Drinking Water Quality In Northern Ireland 2007

Drinking Water Quality in Northern Ireland, 2007 A Report by the Drinking Water Inspectorate for Northern Ireland



Northern Ireland Environment Agency



Drinking Water Quality in Northern Ireland, 2007



A Report by the Drinking Water Inspectorate for Northern Ireland



A Report by the Drinking Water Inspectorate for Northern Ireland



Printed and published by Northern Ireland Environment Agency, Design Studio, Klondyke Building, Gasworks Business Park, Lower Ormeau Road, BELFAST, BT7 2JA ISBN 978-1-905127-80-1 November 2008

Contents Foreword Executive Summary Introduction

2

Part 1 - Public Drinking Water Supplies

5

• Overall Drinking Water Quality

6

• Authorised Departures

21

• Consideration of Provisional Enforcement Orders

21

• Incidents and Events Affecting Drinking Water Quality

22

• The Technical Audit Process

26

• Consumer Contacts for Drinking Water Quality Issues

29

Part 2 - Drinking Water Quality in District Council Areas

33

• Summary of Drinking Water Quality Information

33

• Provision of Drinking Water Quality Information to District Councils

33

Part 3 - Protecting Drinking Water Quality

63

• Drinking Water Quality Improvement Programmes

63

• Implementing the Drinking Water Safety Approach - Water Safety Plans

72

Part 4 - Private Water Supplies

79

• Monitoring Programme for Private Supplies

80

• Drinking Water Quality at Private Supplies

82

Part 5 - Drinking Water Quality Standards and Science

87

• Drinking Water Quality Standards

88

• How to Find Out More about Drinking Water Quality

92

Annexes • Annex 1 - Glossary and Definition of Terms

97

• Annex 2 - Roles and Responsibilities

103

• Annex 3 - Drinking Water Quality Look-up Tables

107

• Annex 4 - Calculations Used in the Report

115

• Annex 5 - Authorised Departures

120

• Annex 6 - Formal Notice Action

123

• Annex 7 - Staffing

125

© Crown copyright 2008 The maps used in this report are based upon Ordnance Survey of Northern Ireland’s data with the permission of the Controller of Her Majesty’s Stationery Office, © Crown copyright and database rights EMOU206.2. Unauthorised reproduction infringes © Crown copyright and may lead to prosecution or civil proceedings. Maps also contain data supplied by Northern Ireland Water Ltd (NI Water) and, as such, are protected by NI Water copyright 2008. Printed on 100% post consumer waste. A copy of this report is available on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/annual_reports.htm

Foreword I am pleased to present our 12th annual report on the quality of drinking water in Northern Ireland. It covers the 2007 calendar year for both public and private water supplies. It is the first report since the Inspectorate became a statutorily appointed body in April 2007, under the Water Reform process, and the fourth since new Regulations for public drinking water supplies came into operation in January 2004. Looking back over the period covered by the 12 reports, there has been a steady improvement in publicly supplied drinking water quality, with an accelerating trend in recent years. The overall compliance with European and national drinking water quality standards for all test results has improved from 98.89% in 1996, to 99.60% in 2007. More improvement work remains to be done, however, and this is highlighted in the report. In addition to achieving improved compliance, it is important for Northern Ireland Water Ltd (NI Water) to maintain and effectively operate existing assets. During 2007, the Inspectorate noted deterioration in water quality supplied from some older treatment works and took enforcement action to ensure that drinking water quality from these works is maintained in the remaining period of their operation, before replacement works come on line. In this report, we have continued to present information that will help the reader understand more easily what drinking water quality is like here in Northern Ireland. I am pleased to see this year’s inclusion of local level reporting, where district council summary information on drinking water quality at consumers’ taps is provided. Looking forwards, the drinking water regulatory processes continue to be developed across the UK, with a more risk-based approach being adopted. NI Water is upgrading five of its large water treatment works and bringing them into supply during the latter part of 2008. I welcome the improvements in drinking water quality that this, together with other ongoing investment in infrastructure, will bring. We will also continue to develop constructive working relationships with NI Water and the new statutory bodies appointed under Water Reform: Northern Ireland Utility Regulator, Department of Regional Development stakeholder units, and Consumer Council for Northern Ireland. I hope you find the report interesting and a useful guide to information on drinking water quality in Northern Ireland.

Randal Scott Chief Inspector of Drinking Water for Northern Ireland November 2008

Executive Summary This is the 12th annual report prepared by the Drinking Water Inspectorate Unit of the Northern Ireland Environment Agency (NIEA), acting in its regulatory role in matters relating to drinking water quality. As with previous reports, it gives an account of the Inspectorate’s assessments of, and its checks on, the quality of drinking water provided by Water Service, who, from 1 April 2007, became Northern Ireland Water Ltd (NI Water). NI Water, a government-owned company, is the sole supplier of public water in Northern Ireland. The report also provides details of the quality of the private water supplies which the Inspectorate regulates. While an overall improvement in drinking water quality has been recorded for 2007, this report and previous reports highlight those water quality issues where compliance with the regulatory standards still has to be achieved. Overall microbiological quality has shown a significant improvement at 99.85% compliance compared with 99.76% achieved last year. There was a significant increase in the number of tests taken from service reservoirs meeting the regulatory standards in 2007, as well as increased compliance at water treatment works and at consumers’ taps. Compliance with microbiological standards is important as contraventions may indicate a breach in the integrity of the water supply system or a failure in the treatment process. Where the condition of a consumer’s tap is the reason for microbiological standards not being met, NI Water advises the consumer accordingly. Drinking water quality at consumers’ taps is assessed using ‘mean zonal compliance’, an index which is calculated using 40 parameters from the regulatory sampling programme. In this reporting year, 13 parameters failed to achieve full compliance: trihalomethanes (THMs), iron, aluminium, lead, manganese, pesticides, total pesticides, turbidity, E. coli, nickel, heptachlor epoxide, colour, and hydrogen ion. Compared with last year, there has been a decrease in the compliance achieved at consumers’ taps: 99.34% reported for 2006; and 99.30% reported for 2007. The main reason for this is the significant increased number of THM contraventions. It is disappointing to note this particular deterioration as there had been a progressively upward trend for THMs: from 68.44% in 2004, 75.37% in 2005 and 83.04% in 2006 to this lower value of 79.37% in 2007. NI Water gave the principal reason for this to be due to changes in raw water quality caused by heavy rain. The Inspectorate has emphasized to NI Water the importance of water treatment processes being robust enough to deal with the changing raw water quality: capable of removing organic matter from the raw water and, hence, reducing THMs in the distribution system. During 2007 the Inspectorate took ‘enforcement action’ to address specific operational issues relating to THM noncompliance of the Authorised Departure values in the Dunore Point, Castor Bay and Seagahan supply areas. The necessary remedial measures in relation to this enforcement action are being implemented by NI Water. The completion of new and upgraded water treatment works by 2009, together with careful operational management of the water treatment works and distribution systems, should significantly progress THM compliance. A major infrastructure project involving the water treatment facilities at Dunore Point, Castor Bay, Forked Bridge, Moyola and Ballinrees should deliver improved water quality to more than 50% of Northern Ireland’s population over the next year. Parameters such as iron, aluminium, manganese and turbidity will show improved compliance with the implementation of the mains rehabilitation programme. Lead compliance is expected to further progress with the continued delivery of the orthophosphate treatment programme. Better pesticide compliance is expected with the adoption of a water safety plan approach by NI Water, which includes enhanced catchment management. Variations in water quality compliance performance continue across Northern Ireland, reflecting the need for completion of current and future planned improvement work schemes. This year in the report, the parameters which have not met the regulatory requirements are listed by water supply zones within the district council areas.

Where NI Water supplies water that does not meet the drinking water standards, it must investigate the cause of the problem and notify the Inspectorate of its findings. The Inspectorate assesses each notification and determines whether the failure is likely to recur. If it considers that this is the case, the Inspectorate requires NI Water to take corrective action. Authorised Departures, formal notice and initiation of enforcement action procedures have been used by the Inspectorate as regulatory mechanisms to target issues of non-compliance with drinking water quality standards. These regulatory processes place a requirement upon NI Water to undertake the necessary remedial measures. Events that affect drinking water quality which occur during the day-to-day operation of NI Water’s treatment works and distribution systems are notified to the Inspectorate, who assesses and follows up on each one. If the Inspectorate considers an event to have been serious enough to present a risk, or a potential risk to public health, then it classifies it as an incident. During 2007, 20 incidents and eight events were notified. Of the 20 incidents so notified, 12 related to situations of compromised disinfection, six related to treatment difficulties and two were caused by other factors. Mitigation of the risks of non-compliance at water treatment works is within NI Water’s control. Where necessary, this is being addressed by NI Water through upgrading water treatment processes and reviewing operational practices. The development of a drinking water safety plan approach is seen by the Inspectorate as an effective way of mitigating risks of contamination in the water supply chain, from the source waters in the catchments, through the water treatment works and onwards through the storage and distribution networks to consumers’ taps. In Part 3 of the report, we have looked at the parameters which can be used to highlight different aspects of water quality issues within the supply chain. As part of the Inspectorate’s ongoing work, we undertook the annual technical audit inspection programme during 2007. This enables us to assess whether good practice is being followed as NI Water carries out its statutory obligations. Following the inspections, we present reports containing our conclusions, recommendations, suggestions and comments to NI Water and we require prompt appropriate follow-up action to be taken.

Current Regulatory Framework The Water Reform process established Water Service, who had been operating as an agency within the Department for Regional Development in Northern Ireland during the first three months of this 2007 reporting period, as a governmentowned company, NI Water, from 1 April 2007. The Water and Sewerage Services (Northern Ireland) Order (2006), while establishing the conditions under which NI Water operates, also defines the roles of the ‘regulators’. These are: the Northern Ireland Authority for Utility Regulation (NIAUR) for ‘economic regulation’; the Department for Regional Development for ‘drinking water regulation’; the Northern Ireland Environment Agency for ‘environmental regulation’; and the Consumer Council for Northern Ireland (CCNI) as the ‘customer representation’. Within this new regulatory framework, there have been inherent changes regarding the role and responsibilities of the Drinking Water Inspectorate for Northern Ireland. The Order appointed all scientific staff within the Drinking Water Inspectorate as inspectors to act on behalf of the Department for Regional Development in respect of public supplies (those supplied by NI Water), and on behalf of the Department of the Environment in respect of private water supplies. Randal Scott was designated as the Chief Inspector of Drinking Water by both Departments. The Inspectorate continues to operate as a functional unit from within the Northern Ireland Environment Agency, an agency of the Department of the Environment in Northern Ireland, on behalf of both Departments. .

Drinking Water Quality in Northern Ireland, 2007

Introduction The Drinking Water Inspectorate (the ‘Inspectorate’) is a functional unit within the Northern Ireland Environment Agency, part of the Department of the Environment. It is one of the United Kingdom’s regional regulatory bodies which have statutory duties in terms of drinking water quality. The duties of the Inspectorate for Northern Ireland apply to both public and private water supplies. A public water supply is one provided by Northern Ireland Water Ltd (NI Water) for the purposes of drinking, washing and cooking or food production. A private water supply is any supply of water provided for the purposes of drinking, washing and cooking or food production, other than by NI Water.

The Inspectorate’s Responsibilities The regulatory framework for water supplies in Northern Ireland has changed. The Water and Sewerage Services (Northern Ireland) Order 1973 was rewritten as ‘The Water and Sewerage Services (Northern Ireland) Order 2006’ to enable the Water Reform process to proceed, whereby, Water Service, the public supplier of water in Northern Ireland, began to operate as a government-owned company (Go Co) from 1 April 2007. Following these legislative changes, the Drinking Water Inspectorate is now a statutory appointee, acting on behalf of the Department for Regional Development (DRD) in respect of public water supplies. It continues to act on behalf of the Department of the Environment in relation to private water supplies. The Order also conferred, for the first time, enforcement powers on the Inspectorate in matters arising with NI Water. The Inspectorate’s role is to provide independent reassurance that human health is safeguarded through the provision of safe public water supplies by NI Water. To be safe, drinking water must be wholesome at the time of supply. Wholesomeness is defined by reference to drinking water quality standards and other requirements set out in the Regulations. Many of the drinking water quality standards come from the 1998 EC Drinking Water Directive which came fully into force on 25 December 2003. The Directive focuses on those parameters of importance to human health (known as mandatory parameters), together with others that reflect the control of water treatment processes and the aesthetic quality of drinking water (known as indicator parameters). The Directive also allows member states to set national standards to ensure that the good quality of drinking water already achieved is not allowed to deteriorate. The Inspectorate‘s regulatory responsibilities for public drinking water supplies are contained within The Water Supply (Water Quality) Regulations (Northern Ireland) 2007; and for private water supplies, within The Private Water Supplies Regulations (Northern Ireland) 1994. Our role is to provide guidance to NI Water on how to carry out these regulatory tests and how to report the results. We undertake independent

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Drinking Water Quality in Northern Ireland, 2007

checks to assess if the testing has been carried out to a high standard of analytical quality control. Our purpose here is to provide public reassurance in relation to the integrity of NI Water’s results. Our role also extends to publishing an annual report which provides summaries of these results. Some of the Regulations address specific aspects of drinking water safety, for example, a requirement to adequately treat and disinfect water supplies, and regulation on the control of the use of chemicals and materials of construction used in public water supplies. We also carry out independent technical audits of NI Water’s records and sites to ensure its operational and management procedures are robust and appropriate. On completion of these inspections, we submit reports containing our conclusions, recommendations, suggestions and comments to NI Water. A summary of the inspections carried out are given later in Part 1 of the report. NI Water must notify the Inspectorate of any event, which by reason of its effect, or likely effect on the quality or sufficiency of drinking water, may give rise to a significant risk to consumers’ health. Others, including consumers, may bring such events to our attention. Our role is to investigate and report on these circumstances. Further details of the events and incidents reported to the Inspectorate in 2007 are given in Part 1 of this report. NI Water must investigate the cause of each test result which does not meet the standard and forward these investigation reports to the Inspectorate. Our role is to assess this information, and, where appropriate, initiate the regulatory processes to enable NI Water to bring about the necessary improvements so that standards can be met in a timely and cost-effective way.

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Drinking Water Quality in Northern Ireland, 2007

Part 1 Public Drinking Water Supplies

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Drinking Water Quality in Northern Ireland, 2007

Part 1 Public Drinking Water Supplies This part of the report gives an overview of the drinking water quality provided by Northern Ireland Water Ltd (NI Water). It provides the Inspectorate’s assessment of NI Water’s performance during 2007 in its duty to deliver drinking water to its customers throughout Northern Ireland.

During this 2007 reporting year, following Water Reform, Water Service, an agency within the Department for Regional Development, became Northern Ireland Water Ltd (NI Water) on 1 April, a government-owned company with responsibility to supply and distribute water throughout Northern Ireland. Table 1.1 illustrates some figures about NI Water.

Table 1.1: NI Water Figures NI Water Assets Number of water treatment works Number of service reservoirs Number of water supply zones Length of mains pipe (km)

43 342 62 26,500

Water Supplied Water supplied (Ml/day)

617

% from surface sources (impounding reservoirs) Ml/day

53

% from surface sources (rivers and loughs) Ml/day

42

% from ground sources (boreholes) Ml/day

5

Population Served Northern Ireland population estimate % population supplied by NI Water Properties connected to the public water supply

1,724,000 99 795,000

Number of district councils

26

Number of health authorities

5

Water Sources In Northern Ireland, water supplies are mostly obtained from surface water (approximately 95%), with the remainder being groundwater sources. Water from all these sources is treated and distributed through approximately 26,500 kms of water mains. A higher percentage of the Northern Ireland population, as compared with Great Britain, lives in rural areas. The average

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Drinking Water Quality in Northern Ireland, 2007

length of water main per head of population connected to the public supply in Northern Ireland is estimated at 15.4 metres compared with 6.2 metres in England and Wales, and 9.0 metres in Scotland. Water source has an important impact on the properties of a drinking water supply, such as taste, hardness, acidity (pH) and mineral content. The predominantly surface water sources in Northern Ireland contain naturally occurring organic materials which need to be removed by water treatment processes. Within Northern Ireland, private water supplies are also used by a small percentage of the population (<1%). Information on the regulation of private water supplies is given in Part 4 of the report.

Drinking Water Quality Testing Throughout 2007, NI Water sampled drinking water across Northern Ireland to test for compliance with the standards in The Water Supply (Water Quality) Regulations (Northern Ireland) 2002 and 2007. The Regulations require that sampling programmes are in place to ensure that water quality is monitored at water treatment works, service reservoirs, water supply points and at consumers’ taps in water supply zones.

Overall Drinking Water Quality In 2007, of the 124,404 tests undertaken by NI Water, 499 (0.40%) failed to meet the standards. This is an improvement compared with the 558 (0.45%) tests which failed in 2006, and is due to improved compliance being reported for water treatment works and service reservoirs. While an overall improvement in drinking water quality has been recorded for 2007, this report and previous reports highlight those water quality issues where compliance with the regulatory standards still has to be achieved. Overall microbiological quality has shown a significant improvement at 99.85% compliance compared with 99.76% achieved last year. There was a significant increase in the number of tests taken from service reservoirs meeting the regulatory standards in 2007, as well as increased compliance at water treatment works and consumers’ taps. Compliance with microbiological standards is important as contraventions may indicate a breach in the integrity of the water supply system or a failure in the treatment process. Where the condition of a consumer’s tap is the reason for microbiological standards not being met, NI Water must advise the consumer accordingly. Certain chemical parameters have still not met the standards, mainly: trihalomethanes (THMs), iron, aluminium, lead and manganese, and significant improvement measures still need to be implemented to progress compliance. THM compliance should be substantially achieved by 2009 with the completion of new and upgraded water treatment works. The implementation of the mains rehabilitation programme should further improve compliance for iron, aluminium and manganese, and lead compliance is expected to increase with the continued delivery of the orthophosphate treatment programme.

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Drinking Water Quality in Northern Ireland, 2007

Table 1.2: Overall Water Quality Number of Tests

Number of Tests Not Meeting the Standards

E. coli

9,471

4

Coliform bacteria

9,471

11

18,942

15

387

0

9,471

50

28,800

65

17,581

5

17,581

43

35,162

48

5,568

3

5,568

31

464

0

2,939

3

14,539

37

23,400

343

22,503

6

60,442

386

68,643

100 (0.15%)

124,404

499 (0.40%)

Water Leaving Water Treatment Works

Microbiological Total Nitrite Turbidity* Total

Water in Service Reservoirs E. coli Coliform bacteria Total Water at Consumers’ Taps or Authorised Supply Points E. coli Coliform bacteria Enterococci Clostridium perfringens* Microbiological Total Zone Chemical Analysis Supply Point Chemical Analysis Total Overall Microbiological Quality* Overall Water Quality*

The key water quality results for 2007 are presented in two tables: one showing results for the microbiological parameters (Table 1.3); the other presents the chemical/physical parameters (Table 1.5). Specific drinking water quality issues are further discussed in Part 3 of this report.

*For year-on-year comparison, note that turbidity results for water leaving water treatment works and Clostridium perfringens results for water samples at authorised supply points are included in the 2007 figures.

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Drinking Water Quality in Northern Ireland, 2007

Microbiological Quality To protect public health, microbiological standards have to be met at each individual water treatment works and service reservoir, and at consumers’ taps. The significance of the individual test results for each microbiological parameter at each monitoring location varies, and a single positive result cannot be interpreted without other information. The microbiological results confirm the overall safety of drinking water supplies, with an overall high level of microbiological quality compliance (99.85%) being achieved in 2007.

Table 1.3: Microbiological Parameters

Test Parameters

E. coli Coliform bacteria

Standard

Total Number of Tests

Number of Tests Not Meeting the Standard

Water Leaving Water Treatment Works 0/100ml 9,471 0/100ml 9,471

Comments

4 11

Number of Water Treatment Works (WTW) Sampled = 43 Water Leaving Service Reservoirs E. coli Coliform bacteria

0/100ml 0/100ml 95% compliance required for each reservoir

17,581 17,581

5 43

338 service reservoirs met the annual 95% compliance rule.*

Number of Service Reservoirs Sampled = 342 E. coli Enterococci

Water Sampled at Consumers’ Taps 0/100ml 5,568 0/100ml 464

3 0

Number of Consumers’ Taps Sampled (Water Supply Zones) = 62

Water Leaving Water Treatment Works Cryptosporidium

<1 oocyst per 10 litres**

130

*Note: Erratum in 2006 Report, Part 1, Table 1.3 – correct figure should read 347 service reservoirs met the 95% compliance rule. **Note: This is a reporting value and not a regulatory treatment standard.

8

0

One site (out of 43 WTWs) is on a continuous sampling programme.

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Drinking Water Quality in Northern Ireland, 2007

E. coli at Water Treatment Works and Service Reservoirs In 2007, across Northern Ireland, a total of 27,052 samples for E. coli testing were collected at water treatment works and service reservoirs. E. coli was detected in nine of these samples: four from water treatment works; and five from service reservoirs. Where the reason for failure was due to insufficient disinfection, sampling error or contamination due to ingress, remedial action was undertaken by NI Water. On detecting E. coli, NI Water is required to act promptly to protect public health. The immediate response when finding E. coli in a sample at a works or at a service reservoir is to carry out substantive investigative work and confirm that the water being received by consumers is safe.

Coliform Bacteria at Water Treatment Works Testing for coliform bacteria at works gives reassurance that water is being treated adequately to remove bacterial and viral pathogens. In 2007, of the 43 works in Northern Ireland, nine sites had coliform bacteria contraventions. The Inspectorate has expressed its concern to NI Water regarding these contraventions. Repeated occurrences of coliform bacteria in samples from the same works in one year are of concern and require action to be taken. In 2007, this situation occurred at two sites: Carron Hill and Dunore Point. Investigative work by NI Water reported disinfection problems and unrepresentative sampling as the reasons for failing to comply with the regulatory standard.

Coliform Bacteria at Service Reservoirs Testing for coliform bacteria at service reservoirs is used to give reassurance that the quality of water held at these strategic locations in the distribution system is adequately maintained. Service reservoirs which are not maintained in good structural condition can be prone to inward leakage from contaminated surface water. Secondary disinfection is installed at some service reservoirs in Northern Ireland, particularly where there are long distribution networks. In such cases, NI Water considers it necessary to boost disinfection levels to achieve a disinfection residual at the end of the network. However, it is imperative that secondary disinfection does not disguise a more fundamental problem with a service reservoir, such as compromised integrity. NI Water continues to develop a programme of inspection, cleaning and refurbishment of service reservoirs. The national standard requires that at least 95% of samples collected weekly from each service reservoir throughout the year are free from all coliform bacteria. In 2007, 342 service reservoirs were sampled and 338 met the regulatory standard. Coliform bacteria were present at 35 (10.2%) service reservoirs during 2007.

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Drinking Water Quality in Northern Ireland, 2007

The number of occasions when coliform bacteria were detected at service reservoirs decreased significantly from 68 in 2006, to 43 in 2007. Investigative work revealed inadequate disinfection on 19 occasions; contamination due to ingress on 12 occasions; and inadequate sampling procedures (resulting in unrepresentative sampling of water going into supply) due to dirty, leaking or exposed sample taps as the reasons for samples failing to meet the regulatory requirements on 10 occasions. No apparent reason was found for the remaining two samples. The Inspectorate expressed its concern to NI Water about these water quality issues, particularly where, due to ingress, disinfection was compromised and the microbiological standards were not met. NI Water is taking the appropriate remedial measures through its service reservoir integrity programme and improved operational practices.

Enterococci and E. coli at Consumers’ Taps The presence of Enterococci, like E. coli, is indicative of faecal contamination and neither bacterium should be found in any drinking water sample. In 2007, Enterococci were not found in any of the 464 samples taken by NI Water at consumers’ taps. In 2007, a total of 5,568 consumer tap samples were tested for the presence of E. coli and three were positive. In these cases, there was no indication from the information provided by NI Water as part of its investigative work, of a faecal contamination event affecting other properties in these zones. Further investigative samples were satisfactory.

Coliform Bacteria at Consumers’ Taps The Regulations require that coliform bacteria samples are collected from consumers’ taps. The network of water mains and service reservoirs which are known as the ‘distribution system’ carry water from the water treatment works to consumers. Regardless of how thoroughly the drinking water has been treated, the condition of the distribution system can have an effect on the quality of water passing through it, including the condition of the internal plumbing within consumers’ premises. In 2007 there has been a decrease in the number of samples that failed to comply with the coliform bacteria standard from samples taken from consumers’ taps: 31 (0.56%), compared with 41 (0.81%) in 2006. Of these samples, follow-up investigations report the condition of consumers’ taps as the reason for 19 (61.3%) of the contraventions. NI Water is required to advise the consumer where the contravention has been attributed to the domestic plumbing and what action, if any, the consumer may take. Samplers used by NI Water are trained to collect samples from consumers’ taps. The Inspectorate, however, continues to express its concern that NI Water’s sampling arrangements for all locations, i.e. water treatment works, service reservoirs and consumers’ taps, should not generate unrepresentative sample results.

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Drinking Water Quality in Northern Ireland, 2007

Cryptosporidium at Water Treatment Works The Regulations require NI Water to carry out an annual risk assessment for Cryptosporidium, and during 2007, of the 43 water treatment works assessed, only one site was identified to be included in a continuous monitoring programme for the detection of Cryptosporidium oocysts. This site blends surface water, where treatment includes disinfection, slow sand filtration and rapid gravity filtration, with water from deep boreholes. Monitoring is carried out in accordance with the document ‘Guidance for the Monitoring of Cryptosporidium in Treated Water Supplies in Northern Ireland’, which is available on the website: www.ni-environment.gov.uk/crypto_guidance_april05.pdf. The Guidance identifies factors that contribute towards the assessment of ‘significant risk’, such as: the catchment; water source type and quality; the type of treatment provided; and history of any drinking water related cryptosporidiosis outbreaks. Risk assessment arrangements were established for public health protection and incorporate a formal notification level of one or more oocysts per 10 litres and an alert level of 0.1 oocysts per 10 litres. Of the 130 tests carried out in 2007, all results were below both the formal notification level and the alert reporting level. During 2007, there were no reports of mains water supply related outbreaks of cryptosporidiosis in Northern Ireland.* Table1.4: Cryptosporidium Monitoring

2007

2006

2005

2004

2003

1

4

5

5

5

130

1,137

1,495

1,519

1,502

0

9

41

8

79

0.00

0.79

2.74

0.53

5.3

0

4

5

3

5

% of sites with oocysts detected in one or more samples

0.00

100

100

60

100

% of detections that were <0.1 oocysts/10 litres

100

100

99.80

100

100

Number of samples >1 oocysts/10 litres

0

0

0

0

0

Number of sites with >1 oocysts/10 litres

0

0

0

0

0

0.00

0.015

0.21

0.08

0.09

43

48

48

50

54

Number of sites sampled Number of samples collected Number of samples with oocysts detected % of samples with oocysts detected Number of sites with oocysts detected in one or more samples

Highest concentration of oocysts/10 litres detected

Number of Water Treatment Works Monitoring

* Data source: Communicable Disease Surveillance Centre (Northern Ireland).

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Drinking Water Quality in Northern Ireland, 2007

Clostridium Perfringens



The Regulations require monitoring for Clostridium perfringens as an indicator parameter, and it can be used in association with other parameters to assess the efficiency of water treatment processes. This organism is a spore forming bacterium that is exceptionally resistant to unfavorable conditions in the water environment: extremes of temperature and pH; and disinfection processes such as chlorination and ultraviolet light. It is a normal component of the intestinal flora of up to 35% of humans and other warm-blooded animals. These characteristics make it a useful indicator of either intermittent or historical faecal contamination of a ground water source, or surface water filtration plant performance. Any detection of Clostridium perfringens should trigger an investigation by NI Water. In 2007, 2,939 tests were carried out for Clostridium perfringens on samples collected from water treatment works. Of these, three failed to meet the standard of 0/100ml. The standards were not met at three of the 43 works sampled: Castor Bay, Ballysallagh and Drumaroad.

Chemical/Physical Quality Drinking water quality at consumers’ taps is assessed using mean zonal compliance (MZC), an index which is calculated using 40 parameters from the regulatory sampling programme. For a description of how mean zonal compliance is calculated, please refer to Annex 4. Compared with last year, there has been a decrease in the compliance achieved at consumers’ taps: 99.34% reported for 2006; and 99.30% reported for 2007. The main reason for this is the significant increased number of THM contraventions. Table 1.5 summarizes the percentage zonal compliance of all the samples taken to represent the quality of water at consumers’ taps in 2007. The 13 parameters which did not achieve full regulatory compliance are listed at the top of the table.

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Drinking Water Quality in Northern Ireland, 2007

Table 1.5: % Mean Zonal Compliance of Samples Taken at Consumers’ Taps Parameter 1

Total Trihalomethanes Iron Aluminium Lead Manganese Pesticides - other 2, 3 substances Pesticides - total substances Turbidity E. coli Nickel

Number of Samples 752 2,012 2,012 464 2,012

% Zonal Compliance 79.37 98.29 98.78 98.79 98.87

17,460

99.03

388

99.71

2,012 5,568 464

99.77 99.80 99.80

388

99.90

Colour

2,012

99.91

Hydrogen ion

2,012

99.98

464

100

Taste

2,012

100

Odour

2,012

100

Sodium

464

100

Nitrate

492

100

Nitrite

492

100

Nitrate/Nitrite Formula

492

100

Copper

464

100

Fluoride

387

100

Heptachlor epoxide

Benzo(a)pyrene

Parameter Arsenic Bromate Cadmium Cyanide Chromium Mercury Antimony Selenium Tetrachloroethene/ trichloroethene (sum of 2 substances) PAHs (sum of 4 substances) Enterococci Boron Tetrachloromethane 1,2-dichloroethane Benzene Aldrin Dieldrin Heptachlor

Total Number of Samples

% Zonal Compliance 100 100 100 100 100 100 100 100

388

100

464

100

464 388 388 388 388 388 388 388

100 100 100 100 100 100 100 100

52,427

Mean Zonal Compliance %

The problems reflected by these parameters which have not achieved full compliance do not apply everywhere in Northern Ireland; full details of the water supply zone areas where each parameter standard has not been met is given in Annex 3. Part 2 of this year’s report presents, for the first time, the water supply zones where compliance has not been achieved at the local level of district council area.

Number of Samples 464 464 464 388 464 388 464 464

99.30

1

24 (38.7%) zones have associated Authorised Departure work programmes. All pesticides other than aldrin, dieldrin, heptachlor and heptachlor epoxide.

2

3(4.8%) zones have associated Authorised Departure work programmes.

3

Comparing the overall percentage MZC across the UK for 2007, Northern Ireland reports 99.30%; Scotland, 99.60%; and England and Wales, 99.96%. The improved compliance reported for England and Wales, and Scotland reflects the substantial investment in improvement programmes which have been delivered to increase compliance. In Northern Ireland there is an ongoing programme being implemented to improve drinking water quality compliance.

13

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Drinking Water Quality in Northern Ireland, 2007

Trihalomethanes (THMs) Trihalomethanes arise when chlorine, which is used to disinfect the water and make it microbiologically safe to drink, is added to water containing naturally occurring organic substances. Drinking water in Northern Ireland is predominantly obtained from surface waters, which are likely to contain naturally occurring organic materials. The leaching of this organic content into water supplies is affected by seasonal variations. Water treatment is necessary to remove the organic material prior to disinfection, and optimization of these processes minimizes the production of THMs. In 2007, THMs remain the parameter for which there is the greatest number of tests failing to comply with the regulatory standards. Of the 752 tests carried out, 243 (32.31%) exceeded the standard. It is disappointing to note that this is a significant increase from the 21.31% tests exceeding in 2006. THMs are discussed in more detail in Part 3 of this report. NI Water must continue to maintain a careful balance between maintaining good bacteriological quality through an adequate disinfection residual, and minimizing chlorine levels to limit the formation of THMs. Where possible, without compromising disinfection, NI Water should continue to strive for lower THM values.

Table 1.6: Trihalomethane Compliance with Regulatory Standards Number of Determinations

% of Determinations Not Meeting 100 µg/l

% of Determinations Not Meeting ADs

2007

752

32.31

5.59

2006

704

21.31

1.14

Iron The regulatory standard for iron has been set for aesthetic reasons because levels persistently above the standard can give rise to discoloured water. There is no health risk from the reported exceedences of the iron standard but the presence of excessive iron may make the appearance and taste of the water unacceptable to consumers. There are various reasons why iron might be present in the water: it may be present in the raw water; iron compounds may be added as part of water treatment; or it can be released as a consequence of the corrosion of iron water mains. In 2007, of the 2,012 samples taken for iron, 34 (1.69%) failed to meet the 200 µg/l standard due to the condition of the distribution network. Of these contraventions, Altmore-Gortlenaghan, Lough Ross, Seagahan, Dorisland, Lough Braden and Limavady Water Supply Zones were of particular significance as they had recurring iron contraventions. NI Water is identifying the location of these contraventions and prioritizing remedial action to effect regulatory compliance within the associated rehabilitation work programme. Iron is discussed in more detail in Part 3 of this report. 14

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Drinking Water Quality in Northern Ireland, 2007

Table 1.7: Iron Compliance with Regulatory Standards Number of Determinations

Number of Determinations Not Meeting 200 μg/l

% of Determinations Not Meeting 200 µg/l

2007

2,012

34

1.69

2006

2,016

45

2.33

Aluminium Aluminium can occur naturally in many water sources, particularly those derived from upland areas. Aluminium compounds are also used as an important part of the processes used in the treatment and purification of water, including the removal of harmful organisms. In addition to this primary role, aluminium-based water treatment removes naturally occurring aluminium from water. The regulatory standard for aluminium is based on aesthetic considerations because high concentrations in water may cause discoloration. In 2007 a total of 2,012 samples were tested for aluminium; 30 (1.49%) exceeded the standard. Inadequate treatment or poor control of the coagulation process may lead to aluminium passing through the treatment works and into the supply where it can accumulate in the distribution network. Of the 30 failures for this year, investigative work by NI Water reported 14 were due to disturbance of the mains; 10 related to a water quality incident in the Drumaroad supply area; and a further two were related to treatment problems. Investigation by NI Water was unable to determine the reason for the remaining four failures.

Table 1.8: Aluminium Compliance with Regulatory Standards Number of Determinations

Number of Determinations Not Meeting 200 μg/l

% of Determinations Not Meeting 200 µg/l

2007

2,012

30

1.49

2006

2,016

36

1.79

15

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Drinking Water Quality in Northern Ireland, 2007

Lead The regulatory requirements are set as an interim lead standard of 25 µg/l which was to be met by 25 December 2003, and a final standard of 10 µg/l to be met by 25 December 2013. Meeting the lead standard is a complex matter because although some lead pipes are owned by NI Water, most belong to consumers, i.e. building owners. Many older properties still have service pipes and internal plumbing wholly or partly comprised of lead. Some lead in drinking water may be due to the use of lead solder on copper pipes not owned by NI Water (the use of lead solder on copper pipes has been banned since the early seventies). Whether or not the lead standard is exceeded at a particular tap depends on a number of factors, an important one being the plumbosolvency of the water (the tendency for lead to dissolve in water). The Regulations require NI Water to carry out a programme of measures (water treatment) to reduce the tendency of water supplies to pick up lead from pipes and fittings. A plumbosolvency strategy to deliver improved compliance for the interim lead standard of 25 µg/l introduced a programme of orthophosphate treatment at all the major water treatment works during 2004. NI Water is currently assessing the effectiveness of this treatment and whether the treatment process has been optimized. NI Water has an ongoing programme of replacement of its part of lead service pipes, which is carried out during mains rehabilitation. NI Water will also replace, free of charge, any of its pipes which may be made of lead in the supply to a property, but only when a written request is received from a consumer who has replaced the portion of lead service pipe for which the householder is responsible. In 2007, of the 464 tests carried out for lead, four (0.86%) exceeded the standard. All of these exceedences occurred in water supply zones which have associated orthophosphate treatment programmes in place, and following further investigation, it was found that two of these exceedences occurred at properties which had lead service pipes. Investigation by NI Water found no apparent reason for the other two exceedences. When the sample has exceeded the standard, NI Water notifies the customers and the local Environmental Health Officer. Lead is discussed in more detail in Part 3 of this report.

Table 1.9: Lead Compliance with Regulatory Standards

Number of Determinations

% of Determinations Not Meeting 25 µg/l

% of Determinations Not Meeting 10 µg/l

2007

464

0.86

1.51

2006

480

0.63

2.92

2005

506

1.38

3.56

16

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Drinking Water Quality in Northern Ireland, 2007

Manganese The regulatory standard for manganese has been set for aesthetic reasons. Manganese occurs naturally in many of Northern Ireland’s water sources and is removed by effective water treatment. Where treatment is inadequate, manganese and iron can accumulate in distribution pipes. Of the 2,012 samples taken in 2007, the manganese standard was not met on 23 (1.14%) occasions. Sixteen failures were due to disturbance of the mains; and six were related to the water quality incident in the Drumaroad supply area. Following investigative work, no reason was found for the remaining contravention.

Pesticides Pesticides are a group of substances that include insecticides, herbicides, fungicides and algicides. The Regulations set standards for individual pesticides, as well as a standard for the sum of all the pesticides. The standards are set with a wide margin of safety. Government guidelines specify that sampling and analysis should be undertaken for those pesticides used in significant amounts on catchments and those most likely to reach water supplies. Water sources may contain traces of pesticide residues as a result of agricultural use (pest control on crops) and nonagricultural use (herbicide for weed control on roads, etc). NI Water is required to assess the risk to drinking water from pesticides in use in its catchments and then develop an appropriate pesticide monitoring programme. The Inspectorate would encourage the development of a water safety plan approach as an effective means of mitigating the risks of contamination within catchments used to provide drinking water sources. During 2007, 48 individual pesticides were monitored. Of the 19,012 determinations, five failed to comply with the regulatory standards. On four occasions the regulatory standard was not met for MCPA, and on one occasion, the regulatory standard for heptachlor epoxide was not met. One of the MCPA exceedences also contravened the total pesticide limit of 0.5 µg/l. MCPA is a herbicide used for controlling broad-leaved weeds in grass and cereal crops. Heptachlor epoxide is a broad spectrum insecticide which is currently banned in the UK. When a pesticide contravention occurs, NI Water liaises with the Northern Ireland Environment Agency’s Pollution Control Team to carry out investigations regarding pesticide usage and control within the relevant catchments. Table 1.10 lists the locations where pesticide contraventions have occurred above the regulatory standard for the last three years. The Inspectorate considers the extent and duration of these regulatory contraventions and takes action, as appropriate. Regulatory action has been taken at two locations: firstly, at Lough Cowey Water Treatment Works, where the Inspectorate has granted an Authorised Departure for mecoprop until this works is decommissioned; and secondly, at Altmore Water Treatment Works, where work was being undertaken to put in place a treatment barrier (powdered activated carbon) to remove pesticides from the source water. 17

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Drinking Water Quality in Northern Ireland, 2007

Table 1.10: Pesticide Exceedences at Water Treatment Works 2007

2

 

 

1

 

 

 

 

 

 

 

 

 

 1

 1

1 2

1

W3396, Mourne at Ballaghanery* W3503, Conlig*

 

W3505, Lough Cowey*

3

W4301, Carmoney W4501, Derg

  1

W4541, Glenhordial Total Number of Exceedences *These sites are no longer in service.

18

4

1

1

 

Pentachlorophenol

 

Glyphosate

 

MCPA

W3301, Dunore Point

W3317, Dorisland

 

Mecoprop

W2706, Camlough

Total Pesticides

1

2005

Isoproturon

1

2,4-D

W2501, Altmore

Mecoprop

W1301, Moyola

MCPA

Total Pesticides

Heptachlor Epoxide

MCPA

Water Treatment Works

2006

 

 

 

 

1

1

 

 

 

 

 1

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

 

 1

 

 

 

 

 

 

 

 

 

 

1

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

4

4

1

1

1

1

4

1

1

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Drinking Water Quality in Northern Ireland, 2007

Nickel Nickel is not normally found in drinking water sources, but traces can be found in drinking water due to contact with nickel-plated or chromiumplated taps. In 2007, of the 464 samples taken, one failed the 20 µgNi/l standard due to the condition of the consumer’s tap.

Colour The 20 mg/l Pt/Co regulatory standard for colour is based on aesthetic considerations: water should be clear and bright. Colour in water comes from naturally occurring humic substances, particularly in acidic water sources derived from peaty type catchment areas. The humic substances responsible for colour may form other compounds (such as THMs) when water is disinfected. Colour can be removed by appropriate treatment. In some circumstances, water may also become coloured as it comes into contact with old iron mains. In 2007, of the 2,012 samples taken, two (0.10%) failed to meet the standard for colour. One of these was caused by the condition of the water mains and the other was due to the quality of the water leaving the water treatment works.

Hydrogen ion (pH) The pH is a measure of acidity (or alkalinity) in water. The Regulations prescribe that pH should be between a minimum value of 6.5 and a maximum value of 9.5. In Northern Ireland, many upland waters used for public supply contain acidic organic material derived from peat. The pH of water supplied is adjusted during treatment to control the corrosion of water mains and to reduce the uptake of metals such as lead, copper and zinc from consumers’ plumbing. Contraventions of the pH standard in treated water can often be related to a problem at the water treatment works. Another, usually temporary cause of contravention of the pH standard, arises from newly installed cement-lined water mains in the distribution system. Of the 2,012 samples taken for pH during 2007, the regulatory standards were not met on one occasion when the minimum value of 6.5 was not achieved, and on three occasions when the maximum value of 9.5 was not met. The contraventions were due to operational difficulties in controlling pH in the associated water treatment works.

Water Quality in Distribution A measure of water quality in distribution is operational performance index (OPI [TIM]), which is based on the mean zonal compliance of three parameters which best reflect the causes of discoloured water: turbidity, iron and manganese. For 2007, the OPI (TIM) is 98.98% (98.87% in 2006) here in Northern Ireland. For Scotland, the OPI (TIM) is 99.15% (98.86% in 2006), and in England and Wales it remains at 99.85% in 2007.

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Table 1.11: Operational Performance Index (OPI [TIM]) Parameter

% Mean Zonal Compliance

Turbidity

99.77

Iron

98.29

Manganese

98.87

OPI (TIM)

98.98

The use of this index will help the Inspectorate to identify more clearly where effort is required to raise the quality of water at consumers’ taps. The range of OPI (TIM) values in 2007 across the water supply zones in Northern Ireland varies from 90.28% to 100%. Failure across the region varies and tends to reflect where the distribution network contains a large proportion of cast-iron mains. Further details on this variation are discussed in Part 3 of this report.

Turbidity The regulatory standard for water leaving a water treatment works is a turbidity value of 1 NTU. The finely suspended particles which cause turbidity in water must be removed by effective water treatment. Where treatment is inadequate, these particles will remain in the water going into supply. A turbidity value of < or = 1 NTU is considered necessary to achieve effective disinfection. Turbidity exceedences occurred at 17 (39.5%) water treatment works in 2007. Of the 9,471 samples taken for turbidity analysis from water treatment works, 50 (0.53%) failed to meet the standard; a significant improvement compared with last year when 1.17% failed to meet the standard. This parameter is often, but not always associated with discoloration, which in turn, can be caused by corrosion within the distribution system. Excessive turbidity can make the appearance of the water unacceptable to consumers. Of the 2,012 tests carried out on samples taken at consumers’ taps in 2007, five samples failed to meet the turbidity standard of 4 NTU for consumers’ taps. Four failures were due to disturbance of the mains and one was related to the internal plumbing of the property sampled.

Contraventions – Follow-up Action If NI Water supplies water that does not meet the drinking water standards, it must investigate the cause of the problem and notify the Inspectorate of its findings. The Inspectorate assesses each notification and determines if the failure is likely to recur.

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If the Inspectorate considers that the failure is likely to recur, NI water is required to put a programme of remedial work in place to improve drinking water quality. The Inspectorate implements the appropriate statutory mechanism to secure or facilitate compliance. During this reporting period, the following statutory mechanisms have been in place: Authorised Departures; formal notices; and consideration of provisional enforcement orders.

Authorised Departures (ADs) Where a water treatment works has been identified as being at risk of failing to meet the regulatory standards, and the existing water treatment is considered inadequate, the Inspectorate agrees a water treatment improvement programme with NI Water which is stated within the terms and conditions of an AD. The Regulations recognize that a period of time may be required during which improvement work must be carried out to bring the drinking water into compliance with the regulatory standards. During 2007, ADs were in place for THMs in 24 water supply zones; two for the individual pesticide MCPA; and one for the individual pesticide mecoprop. Further details of these ADs are contained within Annex 5 of this report.

Formal Notice Action Under the previous 2002 Regulations, formal notice action was a process used by the Inspectorate to make improvements to drinking water quality following the failure of a regulatory requirement. The notices which issued in 2006 related to a range of non-compliances with the regulatory standards for THMs, iron, coliform bacteria and pesticides (MCPA and mecoprop). Further details on these formal notices are contained within Annex 6 of this report. The Inspectorate monitors progress with the implementation of any remedial measures and expressed its concern to NI Water regarding the length of time taken for corrective action to be carried out, particularly action relating to coliform contraventions and the installation of chlorine units. Appropriate enforcement action will be taken for any future similar non-compliances under the new 2007 regulatory regime.

Consideration of Provisional Enforcement Orders The Inspectorate’s assessment of a significant contravention of the Regulations may result in ‘enforcement action’ being taken. In 2007 the enforcement process commenced with three ‘minded to enforce’ letters requesting what action NI Water intended to take to secure compliance in relation to recurring THM contraventions above the granted AD level. The Inspectorate accepted appropriate undertakings from NI Water in relation to the Dunore Point, Castor Bay and Seagahan water supply areas. A summary of the corrective action associated with these three consideration of provisional enforcement orders is given in Table 1.12.

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Drinking Water Quality in Northern Ireland, 2007

Table 1.12: Consideration of Provisional Enforcement Orders Issued in 2007 Water Treatment Works (WTWs) and Associated Water Supply Zones

Parameter

Dunore Point WTWs Dunore East Oldpark Woodvale Breda East Breda West

THMs - recurring AD failures

Castor Bay WTWs Banbridge-Babylon Hill Ballydougan-Ballyhannon Lurgan-Magheraliskmisk Castor Bay-Richill

Seagahan WTWs Seagahan

THMs - recurring AD failures

THMs - recurring AD failures

Corrective Action Replacement of Dunore WTWs as required by the terms and conditions of the Authorised Departure. Implement interim remedial operational measures at the ozonation plant; prioritize a programme of reservoir cleaning; and minimize distribution residence times. Replacement of Castor Bay WTWs as required by the terms and conditions of the Authorised Departure. Implement interim remedial operational measures at the ozonation plant; prioritize a programme of reservoir cleaning; and minimize distribution residence times. Replacement of Seagahan WTWs as required by the terms and conditions of the Authorised Departure. Minimize THM levels through best operational practice; keep chlorination regime under review; prioritize a programme of reservoir cleaning; and review distribution residence times and chlorine levels.

Incidents and Events Affecting Drinking Water Quality The Inspectorate requires NI Water to inform it of all events that have affected, or are likely to affect, drinking water quality or sufficiency of supplies, and where as a result, there may be a risk to consumers’ health. This information is required to be provided according to agreed guidance and reporting procedures. NI Water is also encouraged to notify the Inspectorate of events that may fall outside the criteria but which could, nonetheless, impact on water quality or cause concern to consumers.

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Drinking Water Quality in Northern Ireland, 2007

Assessment of Incidents and Events by the Inspectorate When notified, the Inspectorate assesses NI Water’s provisional information to determine whether it is an incident or event. The Inspectorate defines an incident as a situation where there has been a demonstrable deterioration in the quality of drinking water, giving rise to a significant potential risk to the health of consumers or a significant adverse aesthetic water quality change. Where no such deterioration has taken place, the situation is classified as an event. There is always the potential for incidents and events to happen. What matters is how well NI Water minimizes both the risks of occurrence and the consequences of incidents as it acts to protect public health at all times. The Inspectorate assesses all the information available to determine:

what caused the problem and whether or not it was avoidable;



what NI Water did in response and how it handled the situation;



what lessons can be learned to prevent similar incidents in the future; and



if there were any breaches of the Regulations.

l

l

l



l

There are several typical outcomes of an incident assessment by an inspector and these are set out below:

a letter is sent to NI Water and, where appropriate, copied to other relevant parties to advise that the incident is closed;



a letter is sent to NI Water and, where appropriate, copied to other relevant parties, making recommendations for action which NI Water must take to address deficiencies revealed by the incident; and/or



enforcement action may be taken to ensure that satisfactory remedial measures are put in place to prevent further regulatory contraventions.

l



l



l



Details of Notified Incidents and Events During 2007 During 2007, there was a range of incidents and events notified to the Inspectorate: 20 incidents and eight events, as shown in Table 1.13. Of the 20 incidents, 12 related to situations of compromised disinfection; six related to treatment difficulties; and two were caused by other factors. Mitigation of the risks of non-compliance at water treatment works is within NI Water’s control. This is being addressed by NI Water through upgrading water treatment processes and reviewing operational practices, where necessary.

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Drinking Water Quality in Northern Ireland, 2007

When incidents and events are notified to the Inspectorate, the appropriate district councils and health authorities are also notified. When the circumstances are considered, the appropriate health authorities may require ‘boil water advice notifications’ to be issued by NI Water to the ‘affected’ consumers. During 2007, there were no boil water advice notifications issued.

Table 1.13: Drinking Water Quality Incidents and Events in 2007 Nature and Cause of Incident/Event

Incident or Event Classification Incident

Date and Duration of Incident/Event 8 January 2007 (3 days)

Area and Estimate of Population/Properties Potentially Affected Rathlin Island (130 population)

17 January 2007 (1 day)

Ballinrees Water Treatment Treatment failure led to aluminium and turbidity Works exceedences in the final water. (79,000 population)

9 May 2007 (2 days)

Lisraw Service Reservoir (60 properties)

E. coli and coliform bacteria failures caused by inadequate disinfection.

Incident

16 May 2007 (1 day)

Dunore Point Water Treatment Works (30,000 properties)

Coliform bacteria exceedence due to chlorination failure.

Incident

21 May 2007

Altmore Water Treatment Works (22,000 population)

Pesticide (MCPA) exceedence and also total pesticide limit exceeded. Insufficient treatment to remove MCPA from raw water.

Incident

29 May 2007 (1 day)

Lenamore Springs Water Treatment Works and Teebane West Service Reservoir (350 properties)

E. coli and coliform bacteria exceedences due to chlorination failure.

Incident

29 May 2007 (1 day)

Crocknabohil Service Reservoir (110 properties)

E. coli and coliform bacteria exceedences due to chlorination failure at water treatment works.

Incident

12 June 2007

Dorisland Water Treatment Pesticide (MCPA) exceedence due to breakdown Works of carbon dosing plant. (170,000 population)

Incident

13 June 2007 (3 days)

Scarva - Newry Main (2,300 properties)

Coliform bacteria exceedences at four service reservoirs after chlorination failure.

Incident

20 June 2007 (1 day)

Ballymullock Service Reservoir (400 properties)

Coliform bacteria exceedence due to inadequate disinfection.

Incident

24

Coliform bacteria failures in final waters at the water treatment works, service reservoir and in the water supply zone. Investigation by NI Water was unable to identify a specific reason.

Incident

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Drinking Water Quality in Northern Ireland, 2007



Table 1.13: Continued

Nature and Cause of Incident/Event

Incident or Event Classification Incident

Date and Duration of Incident/Event 3 July 2007 (1 day)

Area and Estimate of Population/Properties Potentially Affected Layde Service Reservoir (8 properties)

E. coli and coliform bacteria exceedences due to inadequate disinfection and possible ingress.

19 July 2007 (2 days)

Altmore Water Treatment Works (22,000 population)

Treatment difficulties led to aluminium exceedences in the works’ final water and in supply.

Incident

19 July 2007 (3 days)

Killylane Water Supply Zone (3,200 properties)

E. coli and coliform bacteria failures due to inadequate disinfection.

Incident

July - September 2007 (2 months)

Drumaroad Supply Area (250,000 population)

Aluminium and manganese exceedences due to a number of factors.

Incident

2 October 2007 (2 days)

Loughans Service Reservoir (120 properties)

E. coli and coliform bacteria exceedences following ingress.

Incident

5 October 2007 (4 days)

Coast Road, Ballygalley (50 properties)

Coliform bacteria exceedences due to inadequate disinfection.

Incident

26 October 2007 (5 days)

Ards Boreholes at Ballycullen (74,500 population)

Introduction of new trunk main led to contraventions of the turbidity standard.

Incident

1 November 2007 Drumaroad Water (5 hours) Treatment Works (250,000 population)

Treatment difficulties led to aluminium exceedences in the works’ final water.

Incident

9 November 2007 Stradreagh Water (2 days) Treatment Works (2,500 population)

E. coli and coliform bacteria exceedences due to chlorination failure.

Incident

21 December 2007 (4 days)

Moyola Water Treatment Works (66,000 population)

Mechanical failure on secondary filters led to turbidity exceedences.

Incident

5 February 2007 (1 day)

Carron Hill Water Treatment Works (10,000 population)

E. coli and coliform bacteria exceedences reported due to unrepresentative sampling.

Event

27 April 2007 (1 day)

Carmoney Water Treatment Works (80,000 population)

Coliform bacteria exceedence reported. No apparent reason.

Event

25

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Drinking Water Quality in Northern Ireland, 2007

Table 1.13: Continued Nature and Cause of Incident/Event

Incident or Event Classification Event

Date and Duration of Incident/Event 12 June 2007 (1 day)

Area and Estimate of Population/Properties Potentially Affected Ballysallagh Water Treatment Works (22,500 population)

13 June 2007 (1 day)

Seagahan Water Treatment Works (15,000 population)

Coliform bacteria exceedence reported. No apparent reason.

Event

13 June 2007 (1 day)

Carron Hill Water Treatment Works (10,000 population)

Coliform bacteria exceedence reported. No apparent reason.

Event

18 June 2007 (1 day)

Lough Fea Water Treatment Works (50,000 population)

E. coli and coliform bacteria exceedences reported. No apparent reason.

Event

6 September 2007 (1 day)

Dunore Point Water Treatment Works (30,000 properties)

Coliform bacteria exceedence reported. No apparent reason.

Event

20 December 2007 (12 days)

Shanmoy Borehole Water Treatment Works (24,000 population)

Turbidity exceedences due to naturally occurring particles.

Event

Coliform bacteria exceedence reported. No apparent reason.

The Technical Audit Process Technical audit is the term used for the process by which the Inspectorate checks that NI Water is complying with its statutory obligations. The audit process also allows the Inspectorate to observe whether current good practice is being followed. The inspector will give advance notice to NI Water and explain the purpose of the visit. To aid this process, NI Water identifies a day-to-day contact person for the inspector, and the Inspectorate has a named inspector who is its point of contact for raising enquiries or resolving concerns. The technical audit process consists of three elements:

• Annual Assessment of Drinking Water Quality Data › A check on the quality of water supplied throughout the year, based on information provided by NI Water . › Checking that NI Water has met its obligations in regard to sampling programmes and improvement programmes.

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Drinking Water Quality in Northern Ireland, 2007

• Inspection of Operational Sites › Announced visits to observe selected activities of NI Water which are relevant to its provision of drinking water and the sampling and testing of drinking water supplies.

• Interim Checks › Carried out on aspects of compliance and based on information provided periodically by NI Water. A summary of the Inspectorate’s findings from the 2007 Inspection Programme are given in the table below.

Table 1.14: 2007 Inspection Programme - Summary of Inspectorate’s Findings Location

Audit Activity

Number of Recommendations

Number of Suggestions

Dorisland Water Treatment Works

To check that good practice in water treatment is being operated.

23

13

Gortlenaghan Water Treatment Works

To check that good practice in water treatment is being operated.

6

4

Killyhevlin Water Treatment Works

To check that good practice in water treatment is being operated.

4

3

Drumaroad Water Treatment Works

Post-incident analysis audit.

5

2

Seagahan Water Treatment Works

Post-incident analysis audit.

8

3

Cabragh, Collone, Magheraliskmisk and Redhills Service Reservoirs.

To check that good practice in water distribution is being operated.

16

8

Mains Rehabilitation Programme

To check that good practice in water distribution is being operated.

10

6

NI Water Laboratories

To check that good practice in the analysis of water samples is being operated.

21

14

NI Water Headquarters

To check that good practice of the ‘Laboratory Information Management System’ is being operated.

4

1

Water Quality Samplers

To check that good practice in the collection of water samples is being operated.

18

13

27

Drinking Water Quality in Northern Ireland, 2007

In 2007, the technical audit programme was satisfactorily undertaken and the Inspectorate acknowledges NI Water’s continued cooperation. NI Water has implemented or provided substantive comment on all recommendations and suggestions within the audit reports. During the year, the Inspectorate introduced the use of summary reports; these were provided to NI Water staff at the conclusion of each audit. These reports summarize the main findings from the audit and also agree a date for provision of outstanding information (if applicable). A final audit report is then produced. This approach is both effective and efficient in terms of communicating the outcomes of the audit process to NI Water. Each audit report presents the main conclusions and any recommendations, suggestions or comments made. A clear distinction is made in audit reports between recommendations, which require a formal written response from NI Water, and suggestions. Recommendations are made only where, in the Inspectorate’s opinion, action is required to avoid a foreseeable risk or a breach of a regulatory duty. If such a breach has occurred, then formal action may be considered. Suggestions are made in relation to matters which do not present such a risk; instead they relate to an aspect of best practice. The Inspectorate has noted that for a number of audits carried out in 2007 there was undue delay in receiving appropriate responses from NI Water, and would expect that responses for future audits will be provided within the required timescales.

28

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Drinking Water Quality in Northern Ireland, 2007

Consumer Contacts for Drinking Water Quality Issues In 2007 the Inspectorate requested NI Water to provide information on the complaints and concerns made by its customers as consumer acceptability of drinking water quality is of interest to the Inspectorate. The majority (66%) of these complaints and concerns show that these were related to the appearance of water (see Fig 1.1). Within this category, the main concern (74%) relates to discoloured water, with consumers experiencing orange, brown or black coloured water at their taps (Fig 1.2 refers). It is expected that the long-term mains rehabilitation programme of the distribution system will improve the appearance of water.

Figure 1.1: Main Categories of Consumer Complaints Received by NI Water in 2007 Appearance - 66% Appearance

66%

Taste and Odour - 13% Illness - 1.1% Particles - 2.7% Animalicles - 17% Other - 17%

Taste and Odour

Other

17%

13%

Illness

Animalicles

0.2%

Particles

2.7%

1.1%

Figure 1.2: Breakdown of the Complaints within the Appearance Category Received by NI Water in 2007

Colour - 74.1% Colour

74.1%

White - Chalk - 10.7% White - Air - 12.4% Stained Washing - 0.4% Hardness - 0.3% General - 2.1%

General

2.1%

White - Chalk

10.7%

White - Air

12.4%

Stained Washing

0.4%

Hardness

0.3%

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Drinking Water Quality in Northern Ireland, 2007

NI Water Contact Details: When a consumer has a drinking water quality concern or complaint, he/she should first contact NI Water’s Customer Service Unit and ask them to investigate. Telephone: E-mail:

08457 440088 [email protected]

Address:

NI Water Customer Relations Centre 4th Floor Capital House 3 Upper Queen Street BELFAST BT1 6PU

If, having discussed your concerns with NI Water and you do not feel that the issue has been satisfactorily resolved, you may contact the Consumer Council.

Consumer Council Contact Details: Telephone: E-mail:

Complaints line 08456 016022 [email protected]

Address:

Consumer Council Elizabeth House 116 Holywood Road BELFAST BT4 1NY

Drinking Water Inspectorate Contact Details: Should a consumer feel it necessary to contact the Drinking Water Inspectorate, he/she should use the contact details below. Telephone: Fax: E-mail:

028 9056 9282 028 9056 9263 [email protected]

Address:

Drinking Water Inspectorate Environmental Protection Division Northern Ireland Environment Agency Klondyke Building Cromac Avenue Gasworks Business Park Lower Ormeau Road BELFAST BT7 2JA

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Drinking Water Quality in Northern Ireland, 2007

Where can I get More Information on the Quality of my Drinking Water? General information on drinking water quality matters is available on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/consumer.htm

NI Water Data Tables A summary of all monitoring data provided to the Inspectorate is published in electronic format in the form of tables and is available on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/public_water/drinking_ water_quality.htm The data summarizes the numbers of samples taken and the numbers of samples failing the standard or specification for each parameter as required by the Regulations.

Information Leaflets Recently, Water UK launched a consumer guide entitled ‘Looking after WATER in your home’. It provides advice on how to maintain the quality of tap water in your home. The Inspectorate is pleased to support this industry-wide guide and has promoted and encouraged its use through NI Water, district councils and the Consumer Council for Northern Ireland. This leaflet can be found on Water UK’s website: www.water.org.uk/home/resources-and-links/waterfacts/looking-after-water

Water Hardness In support of the ‘Looking after WATER in your home’ leaflet, the Inspectorate has produced a more detailed local map indicating the areas of hard and soft water in Northern Ireland. This map can be viewed on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/consumer/water_hardness.htm Hard Water can cause scale deposition to form in water heating appliances, such as boilers, kettles, and washing machines, and can also make it more difficult to work up lather from soaps, washing up liquids and washing powders. Soft waters, on the other hand, may be more corrosive to water pipes. To obtain more detailed information on the water hardness in your area, contact NI Water on: 08457 440088.

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Drinking Water Quality in Northern Ireland, 2007

Part 2 Drinking Water Quality in District Council Areas

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Drinking Water Quality in Northern Ireland, 2007

Part 2 Drinking Water Quality in District Council Areas This part of the report provides summary drinking water quality data presented by local district council areas. Also included is a summary of the responses to a questionnaire about drinking water quality which the Inspectorate issued to the district councils.

Summary of Drinking Water Quality Information In this year’s report, the Inspectorate has introduced a new part, ‘Drinking Water Quality in District Council Areas’ as a way of assisting readers to understand more easily what the water quality is like in water supply zones that are within their local district council area. To do this, the Inspectorate has taken each district council area, and, based on the parameters which are used to assess drinking water quality at consumers’ taps, has listed those which have not achieved full compliance with the regulatory standards. These contraventions have been presented in tables using an indicator measure referred to as ‘mean zonal compliance’. The definition of mean zonal compliance is contained within Annex 4. It is important to note that there are 40 parameters which are used to measure water quality within a water supply zone and that it is only when parameters have not achieved 100 percent compliance, that they are listed on the tables. When a contravention occurs, Northern Ireland Water Ltd (NI Water) carries out an investigation and appropriate remedial action is taken. For summary details of work that is being carried out at specific water treatment works, please refer to Annex 5. For more specific detail on the work being carried out, the reader should contact NI Water’s Customer Service Unit on: 08457 440088. The tables that follow list the water supply zones in the district council areas where there has been a contravention. The reader should note that some water supply zones cover more than one district council area, and where this occurs, the results for the whole zone will be included on more than one district council area page. There continues to be variations in water quality compliance performance across Northern Ireland, reflecting the need for the completion of current and future planned improvement work.

Provision of Drinking Water Quality Information to District Councils District councils use various means to keep themselves informed about drinking water quality. The Regulations require NI Water to provide each district council with an annual report summarizing drinking water quality within its area. NI Water has to inform district councils of events affecting drinking water quality within their areas. District councils may carry out their own monitoring programmes and some will get involved in helping to resolve consumer complaints about drinking water quality.

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The Inspectorate is keen to seek the opinions of each Chief Environmental Health Officer on the quality and safety of drinking water supplies in his district council area, and so for the third year running, the Inspectorate issued a short questionnaire to obtain feedback for inclusion in this annual report. The questions invited views on drinking water quality and the extent to which councils were involved in local water quality issues. Of the 26 questionnaires issued, 19 district councils gave their views. A summary of these views were:

• 17 indicated they were satisfied with the quality of the public water supply;



• one indicated that it was generally satisfied with the quality of the public water supply;



• one council indicated that it was concerned with the regular lack of supply of the public water supply and its effect on water quality;



• 16 favoured reporting of water quality issues on a more local interest level;



• 11 councils would like to have reporting on consumer complaints to be included in the report; and



• 10 councils would like to see more detail given on the reasons/ causes of any local incidents of water quality failures, and common incident outcomes details would be considered useful.

Other comments made by district councils included:

• interest in more detail on all parameters including THMs, Cryptosporidium, lead, aluminium, iron and manganese;



• awareness of lead replacement issues; NI Water lead failure notifications; interest in lead communication pipes and advice to householders; and the issuing of public health notice(s) if necessary; and



• NI Water’s handling of customer complaints.

When the questionnaire was issued previously, a common response was that it would be useful to have reporting of water quality issues on a more local level. Also, through the Inspectorate’s engagement with other ‘parties’, it is often asked about local water quality. It is intended that the tables which follow will provide summary information of water quality compliance at a local level. Another common response to the questionnaires was to have more local information presented on both incidents and events, and on consumer complaints. While it is not possible for the Inspectorate to consider presentation of this information on a local basis, summary information has been presented in Part 1 of this report. For more detailed information on these local issues, please contact NI Water at 08457 440088 or [email protected] 34

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Antrim Borough Council Area Water Supply Zones (WSZs) in Council Area Z105 - Bellaghy Z109 - Dunore North Z110 - Killylane Z310 - Dunore East WSZs Area with no WSZs Lakes/Loughs

Table 2.1: % Zonal Compliance in Water Supply Zones in Antrim Borough Council Area

Sampling Location - Zones Z109, Dunore North

Z110, Killylane

Z310, Dunore East

Parameter Aluminium Iron Trihalomethanes Aluminium Iron Trihalomethanes Iron Trihalomethanes

% Zonal Compliance* 98.08 98.08 83.33 98.08 98.08 37.50 98.08 55.56

*All other parameters in this area achieved full compliance and are therefore not included in this table. Bellaghy Water Supply Zone (Z105) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Ards Borough Council Area Water Supply Zones (WSZs) in Council Area Z305 - Clandeboye Z313 - Lisbane Z316 - Lough Cowey Z317 - North Peninsula WSZs Area with no WSZs

Table 2.2: % Zonal Compliance in Water Supply Zones in Ards Borough Council Area

Sampling Location - Zones Z305, Clandeboye Z313, Lisbane Z316, Lough Cowey Z317, North Peninsula

Parameter Iron Manganese Manganese Trihalomethanes Aluminium Manganese

% Zonal Compliance* 98.08 98.08 95.83 91.67 98.08 98.08

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Armagh City and District Council Area Water Supply Zones (WSZs) in Council Area Z209 - Castor Bay-Shanmoy Z210 - Clay Lake Z219 - Seagahan Z221 - Banbridge-Babylon Hill Z222 - Ballydougan-Ballyhannon Z226 - Fofanny Z227 - Castor Bay-Richill WSZs

Table 2.3: % Zonal Compliance in Water Supply Zones in Armagh City and District Council Area

Sampling Location - Zones Z209, Castor Bay-Shanmoy Z210, Clay Lake

Z219, Seagahan

Z221, Banbridge-Babylon Hill

Z222, Ballydougan-Ballyhannon Z227, Castor Bay-Richill

Parameter E. coli Trihalomethanes Lead Manganese Trihalomethanes Colour Iron Manganese Trihalomethanes Aluminium Manganese Trihalomethanes Trihalomethanes Trihalomethanes

% Zonal Compliance* 98.31 33.33 87.50 91.67 0.00 97.22 94.44 97.22 4.17 95.83 95.83 50.00 44.44 33.33

*All other parameters in this area achieved full compliance and are therefore not included in this table. Fofanny Water Supply Zone (Z226) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Ballymena Borough Council Area Water Supply Zones (WSZs) in Council Area Z104 - Ballymena Borough Z105 - Bellaghy Z106 - Buckna Z108 - Dungonnell Z109 - Dunore North Z110 - Killylane WSZs Area with no WSZs

Table 2.4: % Zonal Compliance in Water Supply Zones in Ballymena Borough Council Area

Sampling Location - Zones Z104, Ballymena Borough Z106, Buckna Z108, Dungonnell Z109, Dunore North

Z110, Killylane

Parameter Iron Trihalomethanes Trihalomethanes E. coli Aluminium Iron Trihalomethanes Aluminium Iron Trihalomethanes

% Zonal Compliance* 97.22 79.17 75.00 97.92 98.08 98.08 83.33 98.08 98.08 37.50

*All other parameters in this area achieved full compliance and are therefore not included in this table. Bellaghy Water Supply Zone (Z105) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Ballymoney Borough Council Area Water Supply Zones (WSZs) in Council Area Z101 - Alcrossagh Z102 - Altnahinch Z107 - Drumabest Z108 - Dungonnell WSZs Area with no WSZs

Table 2.5: % Zonal Compliance in Water Supply Zones in Ballymoney Borough Council Area

Sampling Location - Zones Z101, Alcrossagh Z102, Altnahinch Z107, Drumabest Z108, Dungonnell

Parameter Trihalomethanes Iron Trihalomethanes Nickel E. coli

% Zonal Compliance* 87.50 97.22 62.50 87.50 97.92

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Banbridge District Council Area Water Supply Zones (WSZs) in Council Area Z212 - Fofanny-Banbridge Z221 - Banbridge-Babylon Hill Z222 - Ballydougan-Ballyhannon Z226 - Fofanny WSZs

Area with no WSZs

Table 2.6: % Zonal Compliance in Water Supply Zones in Banbridge District Council Area

Sampling Location - Zones Z212, Fofanny-Banbridge Z221, Banbridge-Babylon Hill

Z222, Ballydougan-Ballyhannon

Parameter Iron Aluminium Manganese Trihalomethanes Trihalomethanes

% Zonal Compliance* 95.83 95.85 95.83 50.00 44.44

*All other parameters in this area achieved full compliance and are therefore not included in this table. Fofanny Water Supply Zone (Z226) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Belfast City Council Area Water Supply Zones (WSZs) in Council Area Z301 - Ballyhanwood Z303 - Breda East Z304 - Breda West Z307 - Dorisland Z309 - Dunmurry Z310 - Dunore East Z318 - Oldpark Z321 - Woodvale Z322 - Purdysburn North WSZs Area with no WSZs Lakes/Loughs

Table 2.7: % Zonal Compliance in Water Supply Zones in Belfast City Council Area Sampling Location - Zones Z301, Ballyhanwood Z303, Breda East

Z304, Breda West Z307, Dorisland

Z309, Dunmurry Z310, Dunore East Z318, Oldpark Z321, Woodvale Z322, Purdysburn North

Parameter Aluminium Manganese Aluminium Manganese Trihalomethanes Lead Trihalomethanes Hydrogen ion Iron Manganese Turbidity Trihalomethanes Iron Trihalomethanes Aluminium Trihalomethanes Trihalomethanes Aluminium Iron Manganese Turbidity

% Zonal Compliance* 98.08 98.08 98.08 98.08 87.50 87.50 75.00 98.68 96.05 98.68 97.22 12.50 98.08 55.56 98.08 69.44 55.56 95.83 95.83 95.83 95.45

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Carrickfergus Borough Council Area Water Supply Zones (WSZs) in Council Area Z110 - Killylane Z307 - Dorisland WSZs Area with no WSZs

Table 2.8: % Zonal Compliance in Water Supply Zones in Carrickfergus Borough Council Area

Sampling Location - Zones Z110, Killylane

Z307, Dorisland

Parameter Aluminium Iron Trihalomethanes Hydrogen ion Iron Manganese Turbidity

% Zonal Compliance* 98.08 98.08 37.50 98.68 96.05 98.68 97.22

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Castlereagh Borough Council Area Water Supply Zones (WSZs) in Council Area Z301 - Ballyhanwood Z305 - Clandeboye Z313 - Lisbane Z315 - Lisnabreeny Z319 - Purdysburn South WSZs Area with no WSZs

Lakes/Loughs

Table 2.9: % Zonal Compliance in Water Supply Zones in Castlereagh Borough Council Area

Sampling Location - Zones Z301, Ballyhanwood Z305, Clandeboye Z313, Lisbane Z315, Lisnabreeny Z319, Purdysburn South

Parameter Aluminium Manganese Iron Manganese Manganese Aluminium Manganese Iron Manganese Trihalomethanes

% Zonal Compliance* 98.08 98.08 98.08 98.08 95.83 94.23 96.15 97.22 97.22 87.50

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Coleraine Borough Council Area Water Supply Zones (WSZs) in Council Area Z102 - Altnahinch Z103 - Ballinrees WSZs Area with no WSZs

Table 2.10: % Zonal Compliance in Water Supply Zones in Coleraine Borough Council Area

Sampling Location - Zones Z102, Altnahinch Z103, Ballinrees

Parameter Iron Trihalomethanes Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 97.22 62.50 98.08 98.08 98.08 62.50

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Cookstown District Council Area Water Supply Zones (WSZs) in Council Area Z111 - Lough Fea Z113 - Moyola Z116 - Unagh Z411 - Lough Macrory WSZs Area with no WSZs Lakes/Loughs

Table 2.11: % Zonal Compliance in Water Supply Zones in Cookstown District Council Area

Sampling Location - Zones Z113, Moyola

Parameter Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 97.22 97.22 97.22 70.83

*All other parameters and water supply zones in this area achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Craigavon Borough Council Area Water Supply Zones (WSZs) in Council Area Z222 - Ballydougan-Ballyhannon Z223 - Lurgan-Magheraliskmisk Z227 - Castor Bay-Richill

WSZs Area with no WSZs Lakes/Loughs

Table 2.12: % Zonal Compliance in Water Supply Zones in Craigavon Borough Council Area

Sampling Location - Zones Z222, Ballydougan-Ballyhannon Z223, Lurgan-Magheraliskmisk Z227, Castor Bay-Richill

Parameter Trihalomethanes Manganese Trihalomethanes Trihalomethanes

% Zonal Compliance* 44.44 98.08 45.83 33.33

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Derry City Council Area Water Supply Zones (WSZs) in Council Area Z403 - Carmoney Z409 - Foyle Z413 - Limavady WSZs Area with no WSZs

Table 2.13: % Zonal Compliance in Water Supply Zones in Derry City Council Area

Sampling Location - Zones Z403, Carmoney

Z409, Foyle Z413, Limavady

Parameter Aluminium Iron Manganese Trihalomethanes Turbidity Trihalomethanes Aluminium Colour Iron Manganese Trihalomethanes

% Zonal Compliance* 94.23 98.08 98.08 87.50 97.92 75.00 97.22 97.22 94.44 94.44 75.00

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Down District Council Area Water Supply Zones (WSZs) in Council Area Z212 - Fofanny-Banbridge Z226 - Fofanny Z308 - Downpatrick Z313 - Lisbane Z315 - Lisnabreeny WSZs Area with no WSZs

Table 2.14: % Zonal Compliance in Water Supply Zones in Down District Council Area

Sampling Location - Zones Z212, Fofanny-Banbridge Z308, Downpatrick Z313, Lisbane Z315, Lisnabreeny

Parameter Iron Aluminium Iron Manganese Aluminium Manganese

% Zonal Compliance* 95.83 88.46 98.08 95.83 94.23 96.15

*All other parameters in this area achieved full compliance and are therefore not included in this table. Fofanny Water Supply Zone (Z226) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Dungannon and South Tyrone Borough Council Area Water Supply Zones (WSZs) in Council Area Z201 - Altmore Z202 - Altmore-Gortlenaghan Z209 - Castor Bay-Shanmoy Z219 - Seagahan Z227 - Castor Bay-Richill Z407 - Killyhevlin Z411 - Lough Macrory WSZs Area with no WSZs

Lakes/Loughs

Table 2.15: % Zonal Compliance in Water Supply Zones in Dungannon and South Tyrone Borough Council Area

Sampling Location - Zones Z201, Altmore Z202, Altmore-Gortlenaghan

Z209, Castor Bay-Shanmoy Z219, Seagahan

Z227, Castor Bay-Richill Z407, Killyhevlin

Parameter E. coli Trihalomethanes Aluminium Iron Manganese Trihalomethanes E. coli Trihalomethanes Colour Iron Manganese Trihalomethanes Trihalomethanes Aluminium

% Zonal Compliance* 91.67 66.67 91.67 79.17 91.67 58.33 98.31 33.33 97.22 94.44 97.22 4.17 33.33 98.68

*All other parameters in this area achieved full compliance and are therefore not included in this table. Lough Macrory Water Supply Zone (Z411) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Fermanagh District Council Area Water Supply Zones (WSZs) in Council Area Z401 - Belleek Z407 - Killyhevlin Z410 - Lough Braden WSZs Area with no WSZs Lakes/Loughs

Table 2.16: % Zonal Compliance in Water Supply Zones in Fermanagh District Council Area

Sampling Location - Zones Z407, Killyhevlin Z410, Lough Braden

Parameter Aluminium Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 98.68 91.67 91.67 95.83 75.00

*All other parameters in this area achieved full compliance and are therefore not included in this table. Belleek Water Supply Zone (Z401) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Larne Borough Council Area Water Supply Zones (WSZs) in Council Area Z106 - Buckna Z110 - Killylane Z307 - Dorisland WSZs Area with no WSZs

Table 2.17: % Zonal Compliance in Water Supply Zones in Larne Borough Council Area

Sampling Location - Zones Z106, Buckna Z110, Killylane

Z307, Dorisland

Parameter Trihalomethanes Aluminium Iron Trihalomethanes Hydrogen ion Iron Manganese Turbidity

% Zonal Compliance* 75.00 98.08 98.08 37.50 98.68 96.05 98.68 97.22

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Limavady Borough Council Area Water Supply Zones (WSZs) in Council Area Z402 - Brishey Z403 - Carmoney Z412 - Stradreagh Z413 - Limavady WSZs Area with no WSZs

Table 2.18: % Zonal Compliance in Water Supply Zones in Limavady Borough Council Area

Sampling Location - Zones

Parameter

Z403, Carmoney

Aluminium Iron Manganese Trihalomethanes Turbidity

Z413, Limavady

Aluminium Colour Iron Manganese Trihalomethanes

% Zonal Compliance* 94.23 98.08 98.08 87.50 97.92 97.22 97.22 94.44 94.44 75.00

*All other parameters and water supply zones in this area achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Lisburn City Council Area Water Supply Zones (WSZs) in Council Area Z212 - Fofanny-Banbridge Z223 - Lurgan-Magheraliskmisk Z308 - Downpatrick Z309 - Dunmurry Z310 - Dunore East Z314 - Lisburn North Z315 - Lisnabreeny Z320 - Stoneyford WSZs Area with no WSZs

Lakes/Loughs

Table 2.19: % Zonal Compliance in Water Supply Zones in Lisburn City Council Area

Sampling Location - Zones Z212, Fofanny-Banbridge Z223, Lurgan-Magheraliskmisk Z308, Downpatrick Z309, Dunmurry Z310, Dunore East Z314, Lisburn North Z315, Lisnabreeny Z320, Stoneyford

Parameter Iron Manganese Trihalomethanes Aluminium Iron Trihalomethanes Iron Trihalomethanes Trihalomethanes Aluminium Manganese Trihalomethanes

% Zonal Compliance* 95.83 98.08 45.83 88.46 98.08 12.50 98.08 55.56 25.00 94.23 96.15 50.00

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Magherafelt District Council Area Water Supply Zones (WSZs) in Council Area Z103 - Ballinrees Z111 - Lough Fea Z112 - Mormeal Z113 - Moyola WSZs Area with no WSZs Lakes/Loughs

Table 2.20: % Zonal Compliance in Water Supply Zones in Magherafelt District Council Area

Sampling Location - Zones Z103, Ballinrees

Z112, Mormeal

Z113, Moyola

Parameter Aluminium Iron Manganese Trihalomethanes Aluminium Iron Manganese Trihalomethanes Turbidity Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 98.08 98.08 98.08 62.50 95.83 95.83 95.83 83.33 95.45 97.22 97.22 97.22 70.83

*All other parameters in this area achieved full compliance and are therefore not included in this table. Lough Fea Water Supply Zone (Z111) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Moyle District Council Area Water Supply Zones (WSZs) in Council Area Z101 - Alcrossagh Z102 - Altnahinch Z108 - Dungonnell Z115 - Rathlin WSZs Area with no WSZs

Table 2.21: % Zonal Compliance in Water Supply Zones in Moyle District Council Area Sampling Location - Zones Z101, Alcrossagh Z102, Altnahinch Z108, Dungonnell

Parameter Trihalomethanes Iron Trihalomethanes E. coli

% Zonal Compliance* 87.50 97.22 62.50 97.92

*All other parameters in this area achieved full compliance and are therefore not included in this table. Rathlin Water Supply Zone (Z115) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Newry and Mourne District Council Area Water Supply Zones (WSZs) in Council Area Z214 - Lough Ross Z224 - Silent Valley-Kilkeel Z225 - Newry-Ballintemple Z226 - Fofanny WSZs Area with no WSZs

Table 2.22: % Zonal Compliance in Water Supply Zones in Newry and Mourne District Council Area

Sampling Location - Zones Z214, Lough Ross Z225, Newry-Ballintemple

Parameter Iron Iron Trihalomethanes

% Zonal Compliance* 83.33 95.83 83.33

*All other parameters and water supply zones in this area achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in Newtownabbey Borough Council Area Water Supply Zones (WSZs) in Council Area Z109 - Dunore North Z110 - Killylane Z307 - Dorisland Z310 - Dunore East WSZs Area with no WSZs

Lakes/Loughs

Table 2.23: % Zonal Compliance in Water Supply Zones in Newtownabbey Borough Council Area

Sampling Location - Zones Z109, Dunore North

Z110, Killylane

Z307, Dorisland

Z310, Dunore East

Parameter Aluminium Iron Trihalomethanes Aluminium Iron Trihalomethanes Hydrogen ion Iron Manganese Turbidity Iron Trihalomethanes

% Zonal Compliance* 98.08 98.08 83.33 98.08 98.08 37.50 98.68 96.05 98.68 97.22 98.08 55.56

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Drinking Water Quality in Northern Ireland, 2007

Water Quality in North Down Borough Council Area Water Supply Zones (WSZs) in Council Area Z302 - Ballysallagh Z303 - Breda East Z305 - Clandeboye Z306 - Conlig Z311 - Holywood Z322 - Purdysburn North

WSZs Area with no WSZs

Table 2.24: % Zonal Compliance in Water Supply Zones in North Down Borough Council Area

Sampling Location - Zones

Parameter

Z302, Ballysallagh

Iron Trihalomethanes

Z303, Breda East

Aluminium Manganese Trihalomethanes

Z305, Clandeboye

Iron Manganese

Z306, Conlig Z311, Holywood Z322, Purdysburn North

Lead Trihalomethanes Aluminium Iron Manganese Turbidity

% Zonal Compliance* 95.83 62.50 98.08 98.08 87.50 98.08 98.08 75.00 25.00 95.83 95.83 95.83 95.45

*All other parameters in these water supply zones achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Water Quality in Omagh District Council Area Water Supply Zones (WSZs) in Council Area Z405 - Glenhordial Z408 - Lenamore Springs Z410 - Lough Braden Z411 - Lough Macrory WSZs Area with no WSZs Lakes/Loughs

Table 2.25: % Zonal Compliance in Water Supply Zones in Omagh District Council Area

Sampling Location - Zones Z408, Lenamore Springs Z410, Lough Braden

Parameter Lead Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 75.00 91.67 91.67 95.83 75.00

*All other parameters and water supply zones in this area achieved full compliance and are therefore not included in this table. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Water Quality in Strabane District Council Area Water Supply Zones (WSZs) in Council Area Z404 - Derg Z408 - Lenamore Springs Z410 - Lough Braden Z411 - Lough Macrory WSZs Area with no WSZs

Table 2.26: % Zonal Compliance in Water Supply Zones in Strabane District Council Area

Sampling Location - Zones

Parameter

Z404, Derg

Aluminium Trihalomethanes

Z408, Lenamore Springs Z410, Lough Braden

Lead Aluminium Iron Manganese Trihalomethanes

% Zonal Compliance* 97.22 50.00 75.00 91.67 91.67 95.83 75.00

*All other parameters in this area achieved full compliance and are therefore not included in this table. Lough Macrory Water Supply Zone (Z411) attained full compliance and is therefore not listed. Where a standard has not been met, NI Water carries out an investigation and appropriate remedial action is taken.

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Part 3 Protecting Drinking Water Quality

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Drinking Water Quality in Northern Ireland, 2007

Part 3 Protecting Drinking Water Quality This part of the report gives a summary of the work which is being undertaken by Northern Ireland Water Ltd (NI Water) to protect drinking water quality in Northern Ireland. It looks at the improvement programmes which are being implemented, particularly where the trihalomethane, iron and lead standards have not been met. It also looks at an outline of the water safety plan approach to risk management and an assessment of NI Water’s performance in supplying water from the catchments through the water treatment works and onwards through its distribution networks to consumers’ taps.

Drinking Water Quality Improvement Programmes at Water Treatment Works (WTWs) Where drinking water quality standards have not been met, NI Water has an ongoing major investment programme to improve water quality compliance. NI Water’s drinking water quality investment plans continue to target the areas of non-compliance, with further improvements to water treatment works underway. During 2007, construction work was completed on the new Carron Hill WTWs, close to Crossmaglen. Construction work progressed in the Alpha Public Private Partnerships Project (PPP) which includes NI Water’s treatment facilities at Dunore Point, Castor Bay, Moyola, Forked Bridge and Ballinrees, which together provide 50% of Northern Ireland’s water supply. The completion of this project (which is currently on target for the end of 2008) should significantly improve compliance, particularly for trihalomethanes (THMs). Improvement work at Clay Lake, which serves Keady and the surrounding area, is in the commissioning stage. Other projects which are necessary to increase compliance are underway for Seagahan and Altmore WTWs.

Drinking Water Quality Improvements - Authorised Departure Compliance Programmes With the agreement of the Inspectorate, programmes of improvement work are put in place to enhance drinking water quality wherever necessary. This involves a regulatory process referred to as ‘Authorisation of Departures’ (ADs). In 2007 there were 24 ADs in place for THMs, and three in place for individual pesticides (two for MCPA and one for mecoprop). Of the THM ADs, 17 will end during 2009 with the delivery of the Alpha PPP schemes. Annex 5 provides details of the Authorised Departures that were in place during 2007.

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Trihalomethanes Trihalomethanes are disinfection by-products that arise when chlorine, which is used to disinfect the water and make it microbiologically safe to drink, is added to water containing naturally occurring organic substances. Drinking water in Northern Ireland is predominately abstracted from surface waters (approximately 95%), which contain naturally occurring organic materials. Water treatment is therefore necessary to remove the organic material prior to disinfection, and optimization of these processes minimizes the production of THMs. A history of inadequate treatment to remove this organic material at many of NI Water’s water treatment works has resulted in a high level of THM non-compliance. NI Water’s drinking water quality investment plans continue to target areas of THM non-compliance. Several schemes to upgrade the water treatment works have already been completed and this is reflected in the trend of improving overall compliance for THMs, particularly in recent years, as can be seen below in Figure 3.1. However, it is disappointing to note that this progressively upward trend has seen a decline in 2007. NI Water gave changes in raw water quality caused by heavy rain as the principal reason for this. The Inspectorate has emphasized to NI Water the importance of water treatment processes being robust enough to deal with the changing raw water quality: capable of removing organic material from the raw water and, hence, reducing THMs in the distribution system.

Figure 3.1: Percentage of Tests Meeting the 100 µg/l THM Standard 100100 90 90 80 80 % Compliance

70 70 60 60 50 50 40 40% Compliance

30 30 20 20 10 10 0

0 2000

2000

2001

2001

2002

2002

2003

2003

2004

Year

2004

Year

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2005

2005

2006

2006

2007

2007

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During 2007 the Inspectorate took ‘enforcement action’ to address specific operational issues relating to THM non-compliance of the Authorised Departure levels in the Dunore Point, Castor Bay and Seagahan supply areas. The necessary remedial measures in relation to this enforcement action are being implemented by NI Water. The completion of new and upgraded water treatment works by 2009, together with careful operational management of the water treatment works and distribution systems, should significantly progress THM compliance. The Alpha PPP project involving the water treatment facilities at Dunore Point, Castor Bay, Forked Bridge, Moyola and Ballinrees should deliver improved water quality over the next year. Looking at the maps (Figures 3.2 - 3.5) that follow, it is apparent that there are variations in THM levels in areas within Northern Ireland: some show improving compliance; while other areas show a marked deterioration in 2007. This largely reflects where improvement work to replace or upgrade existing water treatment works has been delivered, and where schemes are in the process of construction and/or commissioning. Improved compliance is particularly evident in water supply zones in the south-eastern parts of Counties Down and Armagh; the Ards Peninsula; and the south-eastern parts of Belfast, supplied by the new treatment facilities at Drumaroad and Fofanny WTWs (which treat the surface waters derived from upland peaty catchments in the Mourne Mountains). In 2007, notable deteriorations in THM compliance are particularly evident in water supply zones in the mid Armagh area, supplied by Seagahan WTWs, and zones supplied by Castor Bay WTWs in the Craigavon area. THM compliance should be significantly increased as NI Water upgrades its infrastructure over the next two years. In parallel to this, NI Water has an action plan in place targeting better THM compliance: this includes a review of its residual disinfection policy and operational practices at existing water treatment works and distribution systems. NI Water must continue to retain a careful balance between maintaining good microbiological quality through an adequate disinfection residual, and minimizing chlorine levels to limit the formation of THMs. Where possible, without compromising disinfection, NI Water should continue to strive for lower THM levels.

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Figure 3.2: Average THM Values in Water Supply Zones Across Northern Ireland in 2004

Average THM values (µg/l) 0 - 50 50.1 - 100 100.1 - 150 No Mains Water Supply

Figure 3.3: Average THM Values in Water Supply Zones Across Northern Ireland in 2005

Average THM values (µg/l) 0 - 50 50.1 - 100 100.1 - 150 No Mains Water Supply

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Figure 3.4: Average THM Values in Water Supply Zones Across Northern Ireland in 2006

Average THM values (µg/l) 0 - 50 50.1 - 100 100.1 - 150 No Mains Water Supply

Figure 3.5: Average THM Values in Water Supply Zones Across Northern Ireland in 2007

Average THM values (µg/l) 0 - 50 50.1 - 100 100.1 - 150 150.1 - 200 No Mains Water Supply

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Drinking Water Quality Improvement Programmes in Distribution Networks In addition to the upgrade of water treatment facilities, NI Water has an ongoing mains rehabilitation programme to restore or replace the existing water mains pipework. In Northern Ireland, there are approximately 26,500 kms of water mains that deliver water to customers’ taps, and many of these mains are made of cast iron. The condition of the water mains may result in consumers receiving discoloured drinking water due to the presence of iron or manganese. Deposits of these naturally occurring substances have accumulated over many years in the distribution networks as a consequence of their presence in source waters and a lack of effective water treatment. In other situations, where the distribution networks are comprised substantially of old unlined cast-iron water mains, these release iron into the water due to corrosion. Where iron has accumulated in the distribution pipes and these deposits get disturbed, they may cause orange-brown or black discoloration of the water. As part of distribution maintenance, NI Water has operated an ongoing scouring and cleaning programme to minimize these water quality problems. NI Water continues to develop a Water Mains Rehabilitation Programme in which supply zones that experience water quality and other supply problems are subjected to a detailed zonal study. Zonal studies indicate the areas where commencement of water mains rehabilitation should be prioritized. Currently work is planned for the rehabilitation of pipework in 71 areas throughout Northern Ireland. Of these, 36 studies have been completed, with 20 ongoing. Studies on eight further zones are due to commence, with the remaining seven zonal studies still to be programmed. This work has resulted in 50 ‘work packages’ being started, and it is expected that 30 of these ‘packages’ will be completed during 2008. A measure of water quality in distribution used by the UK Drinking Water Quality Regulators is an operational performance index called OPI (TIM), which is based on compliance of three parameters which best reflect the causes of discoloured water: turbidity, iron and manganese. In Northern Ireland, the use of this index helps to identify those areas where more effort is required to raise the quality of water at consumers’ taps. Table 3.1 lists those water supply zones in Northern Ireland which have had an OPI (TIM) less than 100% in the period 2004 to 2007. It is important to note that water supply zones may change from year to year as rezoning takes place and, therefore, some zones included in this table have been incorporated in a new zone. This table shows that OPI (TIM) values across the water supply zones in Northern Ireland range from 83.33% to 100%. Failure to achieve 100% compliance across the region varies and tends to reflect where the distribution networks contain a large proportion of cast-iron mains.

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Table 3.1: Operational Performance Index (OPI [TIM]), 2004 - 2007 Zone Code Z102 Z103 Z104 Z105 Z107 Z108 Z109 Z110 Z111 Z112 Z113 Z116 Z201 Z202 Z204 Z205 Z206 Z207 Z208 Z209 Z210 Z211 Z212 Z213 Z214 Z215 Z216 Z217 Z219 Z221 Z223 Z225 Z301 Z302 Z303 Z305 Z306 Z307 Z308 Z309 Z310 Z311 Z312 Z313 Z314 Z315 Z316 Z317

Water Supply Zone Altnahinch Ballinrees Ballymena Borough Bellaghy Drumabest Dungonnell Dunore North Killylane Lough Fea Mormeal Moyola Unagh Altmore Altmore-Gortlenaghan Ballintemple* Ballydougan* Ballyhannon* Banbridge* Castor Bay* Castor Bay-Shanmoy Clay Lake Fofanny-Ballymaconaghy* Fofanny-Banbridge Fofanny-Newry* Lough Ross Lurgan* Magheraliskmisk* Newry* Seagahan Banbridge-Babylon Hill Lurgan-Magheraliskmisk Newry-Ballintemple Ballyhanwood Ballysallagh Breda East Clandeboye Conlig Dorisland Downpatrick Dunmurry Dunore East Holywood Kilkeel/Annalong* Lisbane Lisburn North Lisnabreeny Lough Cowey North Peninsula

2004 2005 % OPI (TIM) % OPI (TIM) 93.52 97.22   99.07 98.61 97.22 95.24 98.61   98.08   98.61 99.07 91.67 97.10 98.04 97.22 98.55 98.55   96.97  96.19 95.10   98.15 98.61 97.22 99.07

83.33 95.83

 

98.00 83.33 98.63 98.08 99.35

99.07       99.36  94.44  98.61 98.15 97.22 83.33 95.83 94.45      

2007 % OPI (TIM) 99.07 98.72 99.07

99.36 99.36 95.70 98.15

90.28

97.22 98.61

    95.83   95.83  

97.10

2006 % OPI (TIM) 92.59

97.22

97.22

99.07

98.61

94.44     97.22    

94.44

96.93

97.32 99.36

98.72 97.22 99.36 98.72 98.68 99.36

97.22 98.61 99.36 98.61 99.36 98.61 99.36 98.72

99.36 91.67 94.20 97.33

91.67 98.61 98.61 96.00

98.72 98.20

99.36 97.22 98.15

98.72 99.36

*These no longer exist as separate zones. 69

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Table 3.1: Continued Zone Water Supply Zone Code Z318 Oldpark Z319 Purdysburn South Z321 Woodvale Z322 Purdysburn North Z403 Carmoney Z407 Killyhevlin Z409 Foyle Z410 Lough Braden Z411 Lough Macrory Z412 Stradreagh Z413 Limavady Overall OPI (TIM) Percentage Number of Water Supply Zones with OPI (TIM) <100%

2004 2005 % OPI (TIM) % OPI (TIM) 99.36 96.97         99.36 99.07 99.07 98.61 98.61 98.61 91.67 96.30 95.37 98.42 98.85 45.1 42.1

While this table can give an indication of which water supply zones have iron and/or manganese and/or turbidity failures, the index is derived from regulatory samples taken randomly in water supply zones, which are geographically delineated areas. The majority of these failures arise from iron contraventions. It is only with further follow-up investigative work that the location of these failures can be identified; this will then give an indication of which areas within the zones need targeted for appropriate corrective action. The map presented in Figure 3.6 shows the geographical distribution of iron failures across Northern Ireland; these have been reported from regulatory compliance sampling programmes over the last four years.

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2006 % OPI (TIM) 99.36 99.07 99.54   98.72         94.44 98.87 33.3

2007 % OPI (TIM) 98.15 95.70 98.03

95.83

96.29 98.98 48.4

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Drinking Water Quality in Northern Ireland, 2007

Figure 3.6: Iron Contraventions in Water Supply Zones, 2004 - 2007

Improving Compliance with Current and Future Lead Standards It is encouraging to report that all the work carried out by NI Water to date has resulted in a significantly improving trend in lead compliance in Northern Ireland, as shown in Figure 3.7. Looking towards the future and based on monitoring during 2007, 99.14% of tests met the interim standard of 25 µg/l, and the number of tests meeting the future standard of 10 µg/l has increased to 98.49%. To further improve compliance with the lead standard is a complex matter because although some lead pipes are owned by NI Water, most belong to consumers (building owners). The responsibility and cost for replacing lead pipes within the owner’s building is not a drinking water quality regulatory requirement: it is a choice that the owner has to make.

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Figure 3.7: Percentage of Tests Meeting the Current and Future Standards for Lead, 2002 - 2007

100 100 100

% Compliance

95 95 95 90 90 90

% %%Compliance Compliance 25µg/l Compliance25µg/l 25 µg/l % Compliance 25µg/l % Compliance 10µg/l % Compliance 10µg/l %%Compliance Compliance10µg/l 10 µg/l

85 85 85 80 80 % % Compliance Compliance 80 % Compliance 75 75 75 70 70 70

2002 2002 2002

2003 2003 2003

2004 2004 2004

Year Year Year

2005 2005 2005

2006 2006 2006

2007 2007 2007

In addition to regulatory samples, NI Water collects samples in response to consumer requests and for other operational reasons. In 2007, the Inspectorate noted that a significant number of operational samples (160) failed the 25 µg/l standard for lead. The main reason for this would be the considerable amount of building renovation work within the Belfast area, where traditionally lead pipe work would have been used. Implementing the Drinking Water Safety Approach Water Safety Plans The primary objectives of a water safety plan designed to protect human health and ensure good water supply practice are: the minimization of contamination of source waters; the reduction or removal of contaminants through appropriate treatment processes; and the prevention of contamination of the distribution network and domestic (building) water systems. A water safety plan is the most effective way of ensuring that a water supply is safe for human consumption. It is based on a comprehensive risk assessment and the adoption of a risk management approach for each of the steps in a water supply chain, from catchment to consumer. NI Water continues to develop its drinking water safety plans which will involve identification of the hazard(s) and calculation of risk of that/ those hazard(s) which could potentially threaten each stage of the water supply process, to ensure that effective controls are in place to protect drinking water quality.

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Water Safety Performance In last year’s report, the Inspectorate looked at parameters which can be used to highlight different aspects of water quality issues within the water supply chain in Northern Ireland. We have continued to look at performance for 2007 using the same parameters. The tables which follow also include 2006 figures for reference.

Water Sources (Catchment) The Drinking Water Quality Regulations do not require NI Water to sample its water sources, although sampling is undertaken for operational reasons. Table 3.2 shows a summary of selected results of tests carried out on samples taken during 2007 from water sources (mainly reservoirs [53%] and rivers and loughs [42%]) used for public supplies in Northern Ireland. The summary data gives an indication of the range of water quality that NI Water is normally required to treat in order to comply with the Drinking Water Quality Regulations.

Table 3.2: Summary of Data from Sampling of Water Sources Parameter Name Coliform bacteria (per 100mls) E. coli (per 100mls) Enterococci (per 100mls) Colour (mg/l Pt/Co) Hydrogen ion (pH) Manganese (µg/l) Iron (sol) (µg/l) Ammonium (mg/l) Nitrate (mg/l) Pesticides - total (µg/l)

Number of Tests 86 86 45 163 163 86 86 163 163 45

2007 Minimum Value 0 0 0 0.7 5.59 1 12 0.1 0.1 0.02

2007 Maximum Value 37,800 14,700 120 483 9.96 19,005 8,569 6.54 46.5 0.56

2007 Average Value 1,023 286 15 56 7.54 433 686 0.09 3.78 0.08

2006 Average Value 1,000 115 14.3 60 7.5 104 430 0.03 3.9 0.06

NI Water should assess the risks within its catchments and establish monitoring programmes as necessary. This is part of the catchment management planning process which will be used to inform drinking water safety plans. These monitoring programmes are necessary for the management of NI Water’s treatment processes in the provision of safe drinking water supplies. This is particularly important in relation to establishing baseline information on raw water quality to evaluate changes such as increased natural organic matter.

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Water Treatment In 2007, risks of water treatment non-compliance continued to be particularly significant for the process control parameters, notably, THMs and aluminium. THMs have been discussed earlier in this part of the report. Good operational control of the water treatment process using aluminium-based coagulants will mitigate the risk of non-compliance with the aluminium standard. Table 3.3: Water Treatment Indicators

Process Control Parameters Colour Hydrogen ion Nitrate Nitrite Aluminium Trihalomethanes Bromate

Place of Sampling Water Supply Zones Water Supply Zones Water Supply Zones Water Treatment Works Water Supply Zones Water Supply Zones Water Supply Zones

% of Tests Not Meeting the Standards in 2007 0.10 0.15 0 0 1.49 32.31 0

Disinfection Parameters Coliform bacteria E. coli Turbidity

Water Treatment Works Water Treatment Works Water Treatment Works

0.12 0.04 0.53

% of Tests Not Meeting the Standards in 2006 0.36 0.21 0 0.13 1.79 21.31 2.08

0.15 0.05 1.17

The second grouping of parameters in the water treatment table looks at the effectiveness of disinfection and pathogen removal. It is encouraging that in 2007 there has been improved compliance with coliform bacteria, E. coli, and, in particular, turbidity. To safeguard drinking water from the risk of microbiological organisms being present, the process of effective disinfection is fundamental to treatment works’ operation. It is therefore paramount that NI Water achieves its primary duty of disinfecting drinking water before it is supplied to consumers and that there are appropriate critical control measures in place. Water Distribution Systems In Table 3.4, two measures are used which describe the cleanliness of the distribution system from where the water leaves the treatment works up to the point of supply to consumers. The selection of distribution parameters is to reflect the age, condition and maintenance status both of the pipes (water mains) and, to a lesser extent, the reservoirs which comprise the distribution networks. The distribution grouping of parameters has previously been discussed under the name of OPI (TIM) earlier in this part of the report (Table 3.1 refers). OPI (TIM) for 2007 is 98.98%; for 2006, it was 98.87%.

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Table 3.4: Water Distribution Indicators

Place of Sampling

% of Tests Not Meeting the Standards in 2007

% of Tests Not Meeting the Standards in 2006

Water Supply Zones Water Supply Zones Water Supply Zones

0.25 1.69 1.14

0.05 2.33 0.41

Service Reservoirs Service Reservoirs

0.24 0.03

0.38 0.03

Distribution Maintenance Turbidity Iron Manganese Reservoir Integrity Coliform bacteria E. coli

Microbiological sampling takes place weekly at service reservoirs as a check on their integrity and general hygienic status. The assessment of reservoir integrity is based on this microbiological quality. In 2007 there were 342 service reservoirs used in Northern Ireland in the supply and distribution of water to consumers. Like disinfection, the integrity of reservoirs gives information on the fundamental water safety record of NI Water as regards to risk of ingress of contaminants. Secondary disinfection is carried out through chlorine boosting at selected service reservoirs in Northern Ireland (particularly those with long distribution networks) to achieve a disinfection residual at the end of the network. However, it is imperative that secondary disinfection does not disguise a more fundamental problem such as compromised reservoir integrity because of the condition (structural integrity) of the reservoir or its configuration (flow management). The Inspectorate has noted that during the year a number of reservoirs with non-trivial microbiological failures have been taken out of service because of integrity problems. In other situations, reservoirs with non-trivial failures were placed on a refurbishment programme of service reservoir integrity.

Water Systems within Buildings Domestic water systems (buildings), particularly the consumer’s drinking water tap, is the point where water is taken for consumption and is therefore where water is judged to be satisfactory, or not, as the case may be. Not all parameters that are monitored for regulatory purposes are wholly within NI Water’s control. Certain parameters are influenced by the nature and condition of water distribution systems within buildings. The parameters in Table 3.5 are selected to assess building water systems.

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Table 3.5: Indicators for Water Systems within Buildings

Building Water Systems Coliform bacteria E. coli Enterococci Nickel Lead Sodium Copper

Place of Sampling

% of Tests Not Meeting the Standards in 2007

% of Tests Not Meeting the Standards in 2006

Water Supply Zones Water Supply Zones Water Supply Zones Water Supply Zones Water Supply Zones Water Supply Zones Water Supply Zones

0.56 0.05 0 0.22 0.86 0 0

0.81 0.08 0 0 0.63 0 0

In assessing the microbiological failures at consumers’ taps it is important to note that the condition of consumers’ taps is something over which NI Water has no control. NI Water is responsible for ensuring that its samplers are trained to lift representative samples. The percentage of tests that failed to comply with the coliform bacteria standard in samples taken at consumers’ taps has shown a significant decrease from 0.81% in 2006, to 0.56% in 2007. Follow-up investigative reports indicate that the conditions pertaining to the sampling of consumers’ taps are the reason for 61.3% of the failures. As a way of helping consumers understand what steps they can take to control risks arising within their homes, the Inspectorate has supported an industry-wide initiative, whereby, Water UK launched a guide called ‘Looking after WATER in your home’ which is available from the website: www.water.org.uk/home/resources-and-links/waterfacts/looking-after-water

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Part 4 Private Water Supplies

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Drinking Water Quality in Northern Ireland, 2007

Part 4 Private Water Supplies

In this part of the report, we give details of the private water supplies for which the Inspectorate has responsibility.



Introduction Northern Ireland Water Ltd (NI Water) supplies water to over 99% of the Northern Ireland population; the remainder of the population has private water supplies. Private water supplies are defined in The Water and Sewerage Services (Northern Ireland) Order 2006 as any supplies of water provided otherwise than by NI Water. Private water supplies are diverse in nature, and there are a range of users: from those which supply single domestic dwellings, to those supplying large commercial activities. The private water supplies for which the Drinking Water Inspectorate for Northern Ireland has a regulatory responsibility under The Private Water Supplies Regulations (Northern Ireland) 1994, are those which serve more than one household and are used for drinking, washing and cooking; or those used in commercial food production: the making, processing, preserving, preparing, or marketing of food or drink (including water) for sale for human consumption. The regulations are implemented by the Inspectorate, with the sampling duties carried out under an agreement with district councils, and in the case of dairy farms, the sampling and analysis is carried out by the Department of Agriculture and Rural Development. There are 1,266 private supplies currently registered with the Inspectorate. It is estimated that there are a further 4,000 private supplies to individual private domestic dwellings and these are not required to be registered under the regulations. Although there are some (mainly commercial) private supplies in urban areas, the majority are situated in the more remote, rural parts of Northern Ireland. Private water supplies may be drawn from a variety of surface and groundwater sources. Surface sources include streams, rivers and lakes; groundwater sources include wells, boreholes and springs. The majority of private supplies in Northern Ireland are from groundwater sources. In Northern Ireland, 91% of the private water supplies registered with the Inspectorate relate to dairy farms; the remaining 9% relate to other commercial and domestic supplies.

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Monitoring Programme for Private Supplies Private water supplies are split into two categories and further assessed into classifications: • category 1 - a supply that is used only for drinking, washing or cooking by people living in properties receiving the supply: water used solely for domestic purposes. Category 1 supplies are placed in classes A to E depending on the number of people supplied, or volume of water used; and • category 2 - a supply that is used to make food or drink that is sold, or is used in properties with a regularly changing population, for example, hospitals, hotels, caravan sites or schools. Category 2 supplies are placed in classes 1 to 5 depending on the volume of water used. A breakdown of the number of private water supplies within each classification is shown below in Table 4.1.

Table 4.1: Number of Private Water Supplies by Classification Classification

Number of Supplies

% of Total

2.5 Dairy Farms 2.5 2.4 2.3 2.2 2.1 1.E Total No.

1,152 9 48 22 15 1 19 1,266

91.00 0.71 3.79 1.74 1.18 0.08 1.50 100

Classifications Excluding Dairy Farms Number of % Excluding Dairy Supplies Farms 9 7.89 48 42.11 22 19.30 15 13.16 1 0.88 19 16.67 114 100

Depending on the classification, a sampling and analysis programme is put in place for each individual private supply. The frequency of the sampling and the range of parameters tested for are based on the nature of the supply. Dairy farms are tested for microbiological parameters. All other registered private water supplies are sampled and tested for microbiological parameters along with a range of physical/chemical parameters. Table 4.2 shows the monitoring frequencies for selected individual classifications.

Table 4.2: Private Water Supplies - Monitoring Frequencies by Classification Classification 2.1 2.2 2.3 2.4 2.5 1.E

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Average Daily Volume (m3/day) >1,000 101 - 1,000 21 - 100 2 - 20 <2 <5

Number of People Served by the Supply >5,000 505 - 5,000 105 - 504 10 - 104 <10 <25

Monitoring Frequency (Samples/Annum) 24 12 6 2 1 1

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4 Number of Supplies

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Number of Supplies

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2

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Drinking Water Quality in Northern Ireland, 2007

8

6

8

The sampling of private water supplies, excluding dairy farms, is carried out on behalf of the Inspectorate by the Environmental Health Departments of 6 the relevant district councils. The Inspectorate has a contract in place for the analysis of samples taken by the councils, and this requires that all analysis 6 must be carried out by UKAS (or equivalent) accredited laboratories. 6

4

A separate sampling, analysis and reporting programme for dairy farms Number of Supplies is carried out by the Quality Assurance Branch of the Department of 4 Agriculture and Rural Development (DARD), and reported annually to the Number of Supplies The AFBI laboratory located at Newforge which has UKAS Inspectorate. 4 accreditation, undertakes the analysis for samples taken at dairy farms. The of Supplies 4 Quality Number Assurance Branch of DARD takes responsibility for investigating and 2 acting upon contraventions of the regulatory standards for private supplies Number of Supplies 2 at dairy farms.

2 The Inspectorate acknowledges the cooperation of staff from both the Quality Assurance Branch of DARD and AFBI‘s Newforge Laboratory, and 2 0 from the relevant district council Environmental Health Departments Ards BC Derry CC Down in carrying out our activities in relation to the Private Water Supplies DC Antrim BC 0 Regulations. Ards BC 0

Larne BC

Coleraine BC Li Derry CC Down DC Ballymena BC Banbridge DC Craigavon BC Antrim BCArmagh C&DC Cookstown DC Fermanagh DC 0 Ballymoney BC A breakdown Ardsof BCprivate water supplies by district council area is shown Coleraine BC Derry CC Down DC Ballymena BC Banbridge DC Craigavon BC below in Figure 4.1 Antrim BC Armagh C&DC Cookstown DC Fermanag 0 Ballymoney BC Ards BC Coleraine BC Derry CC Down Ballymena BC Banbridge DC Craigavon BC Antrim BC Armagh C&DC Ballymoney BC Cookstown DC Ards BC Coleraine BC Dungannon & Sth Tyr BC Derr Ballymena BC Banbridge DC Craigavon BC Antrim BC Armagh C&DC Ballymoney BC Cookstown DC Ards BC Dungannon & Sth Ty Coleraine BC 2.5 1.E 2.1 2.2 2.3 2.4 Ballymena BC Banbridge DC Craigavon BC Antrim BC Armagh C&DC Ballymoney BC Cookstown DC

.

Figure 4.1: Private Water Supplies, 2007 - by District Council Area (Incorporating Classifications)

10

10

Dungann Coleraine BC2.5 2.1 2.2 2.3 2.4 Ballymena BC Banbridge DC C Armagh C&DC Ballymoney BC Cookstown D

8

8

6

6

4

1.E

2.1

2.2

2.3

2.4

1.E

2.1

2.2

2.3

1.E

2.1

2.2

1.E

2.1

4

Number of Supplies

2.1

2.2

2.3

2.4

Magherafelt DC

Strabane DC

Moyle DC

Newtownabbey BC

Newry & Mourne DC

Lisburn CC

Limavady BC

Moyle DC

Magherafelt DC

Fermanagh DC

Lisburn CC

Larne BC

Dungannon & Sth Tyr BC

1.E

Limavady BC

Larne BC

Derry CC Down DC

Coleraine BC Ballymena BC Banbridge DC Craigavon BC Armagh C&DC Ballymoney BC Cookstown DC

Fermanagh DC

Dungannon & Sth Tyr BC

Down DC

Derry CC

Craigavon BC

Cookstown DC

Coleraine BC

Banbridge DC

Ards BC

Ballymoney BC

Antrim BC

Ballymena BC

0

Armagh C&DC

0

2

Ards BC

2

Antrim BC

Number of Supplies

1.E

Strabane DC

Newtownabbey BC Newry & Mourne DC

2.5

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Figure 4.2: Private Water Supplies (Excluding Dairy Farms) in 2007

Drinking Water Quality at Private Supplies Since June 1999, the Inspectorate has been carrying out a sampling and analysis programme at private water supply sites. The following tables and graphs provide summary information for the most recent periods. Table 4.3 provides an overview of the quality of water in private water supplies. The results show that out of a total of 12,723 tests carried out in 2007, 97.37% met the regulatory standards. The regulatory requirements were not met on 334 occasions.

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Table 4.3: Overall Water Quality in Private Water Supplies, 2005 - 2007  

 

Determinations in 2006

Determinations in 2007 Parameters  

Total coliforms Faecal coliforms Trihalomethanes Manganese Iron Odour (quantitative) Aluminium Oxidizability Colour Ammonium Turbidity Hydrogen ion (pH) Sodium Magnesium Nitrate Sulphate Temperature Nitrite Calcium Conductivity Taste (quantitative) Total pesticides Individual pesticides Other parameters Total

 

Exceeding PCV Total No. 961 961 180 181 180 171 180 131 180 180 217 254 130 131 220 131 418 220 131 253 134 67 838 6,274 12,723

No. 114 94 8 21 23 2 1 2 3 3 7 10 2 2 4 4 1 1 0 1 0 1 4 26 334

% 11.86 9.78 4.44 11.60 12.78 1.17 0.56 1.53 1.67 1.67 3.23 3.94 1.54 1.53 1.82 3.05 0.24 0.45 0.00 0.40 0.00 1.49 0.48 0.41 2.63

 

Exceeding PCV Total No. 1,024 1,024 173 176 176 161 176 121 175 175 221 248 121 121 222 122 475 234 121 249 122 69 877 6,075 12,658

No. 154 123 11 27 22 1 0 0 1 1 8 7 2 1 4 4 2 1 1 0 4 1 3 41 419

% 15.04 12.01 6.36 15.34 12.50 0.62 0.00 0.00 0.57 0.57 3.62 2.82 1.65 0.83 1.80 3.28 0.42 0.43 0.83 0.00 3.28 1.45 0.34 0.67 3.31

Determinations in 2005   Total No. 1,201 1,201 169 169 160 160 169 118 170 168 201 252 118 129 207 119 448 264 118 254 118 70 910 5,617 12,510

Exceeding PCV No. 168 141 14 27 21 1 2 2 1 6 10 1 2 0 1 1 5 0 0 0 2 0 2 15 422

% 13.99 11.74 8.28 15.98 13.13 0.63 1.18 1.69 0.59 3.57 4.98 0.40 1.69 0.00 0.48 0.84 1.12 0.00 0.00 0.00 1.69 0.00 0.22 0.27 3.37

Note: The results are reported to the standards in the 1998 Drinking Water Directive. Physical/ Chemical Quality Contraventions of the physical/chemical standards have been reported for a range of parameters. As with previous years where the standards have not been met, the contraventions relate mainly to iron (12.78%), manganese (11.60%), and trihalomethanes (THMs)(4.44%).

Microbiological Quality The overall microbiological quality for all private water supplies is given in Figure 4.3, where it is subdivided into compliance at dairy farms and compliance at all other registered private water supplies (excluding dairy farms). Within Figure 4.4 these compliance rates are further subdivided into classifications for 2007. This shows a compliance rate among private water supplies serving small domestic supplies, classification 1.E, to be lower than the larger category 2, commercial supplies. 83

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Figure 4.3: Summary of Overall Microbiological Quality

Figure904.3: Summary of Overall Microbiological Quality 100

100

% Compliance 85

% Compliance

95

90

95

90

80

85

% Compliance 85

80

80

75

75

Figure ofofMicrobiological Figure4.4 4.4Summary Summary MicrobiologicalQuality Qualityfor for2007 2007bybyClassification Classification 75 2003

20042003 2003

2005 2004 2004

2005 2003 2004

2004

2005

2006

20062005 2005

Total coliforms - non dairy sites

iforms - non dairy sites

20072006 2007

2007 2006 2006

2007

Total coliforms - dairy sites

Faecal-coliforms non Faecaldairy coliformssites - non dairy sites Total coliforms non dairy- sites

Total - dairy Total coliforms - dairy coliforms sites Faecal coliforms - dairy sites Faecal coliforms - non dairy sites sites

Total coliforms - non dairy sites

Faecal coliforms - non dairy sites

Faecal coliforms non dairy sites - non dairy sites

20062005

2007

Faecal coliforms - dairy sites Total coliforms - dairy sites

Faecal coliforms - dairy sites Faecal coliforms - dairy sites

coliforms Faecal coliforms - Total non dairy sites - dairy sites

Faecal- coliforms Total coliforms dairy sites- dairy sites

Figure 4.4: Summary of Microbiological Quality for 2007 by Classification

Classification

Figure 4.4 Summary of Microbiological Quality for 2007 by Classification

2.1

2.1

2.2

2.2

2.3

2.3

2.4

2.4

Classification

Dairy Farms Dairy Farms (2.5) (2.5) 2.5

2.5

1E

1E

0

0 1010

2020

10

20

10

20

3030

30

40

30 4040

40

50

50 % Compliance 5050

Total Coliforms

60

70

60

70 6060

Faecal Coliforms

% Compliance %% Compliance Compliance

Total coliforms

Total Coliforms Total Coliforms

84

Faecal coliforms

Faecal Coliforms Faecal Coliforms

80

80 7070

90

90

100

100 8080

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Pesticides An ongoing pesticide monitoring programme is undertaken for private water supplies. In 2007, the Inspectorate’s sampling programme recorded four pesticide failures of the regulatory standard at four individual sites. On two occasions, the pesticide detected was glyphosate; the remaining two failures were for the pesticides atrazine and isoproturon.

Follow-up Actions on Regulatory Exceedences Exceedences of the regulatory standards at private water supplies are initially reported by the Inspectorate to the relevant district council who will then subsequently inform the owners/users. All contraventions are investigated by the Inspectorate in conjunction with the appropriate Environmental Health Department, and remedial actions are taken depending on the nature and level of the failure. These actions may include carrying out site visits and offering technical advice to owners/ users on treatment options, as well as providing practical advice on source protection of their private supplies to reduce the potential risks of contamination.

Further Information Following collaboration between the UK regions, a technical manual on private water supplies has been published. The manual provides comprehensive guidance and detailed technical advice for owners/users of private water supplies and is a useful tool for those required to assess or work with these supplies. A copy of the manual and other general information relating to private water supplies can be downloaded from the following website: www.privatewatersupplies.gov.uk

Other Useful Websites Further information on private water supplies and general information on drinking water quality can also be found at the following websites:

Drinking Water Inspectorate for Northern Ireland www.ni-environment.gov.uk/environment/drinkWater/private_water.shtml

World Health Organization www.who.int/water_sanitation_health/dwq/gdwq3rev/en/index.html

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Part 5 Drinking Water Quality Standards and Science

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Part 5 Drinking Water Quality Standards and Science How is Drinking Water Quality Regulated? The Legal Framework The Drinking Water Inspectorate for Northern Ireland was formed in 1996 to provide independent reassurance that public water supplies in Northern Ireland are safe, and that drinking water quality is acceptable to consumers. The regulatory framework for water supplies in Northern Ireland has been changed from The Water and Sewerage Services (Northern Ireland) Order 1973 to The Water and Sewerage Services (Northern Ireland) Order 2006. This enabled the Water Reform process to proceed, whereby, Water Service, the public supplier of water in Northern Ireland, began to operate as a government-owned company, Northern Ireland Water Ltd (NI Water) on 1 April 2007. A public water supply is one provided by NI Water for the purposes of drinking, washing, cooking or food production. Water supplies that are not provided by NI Water are known as private water supplies.

Wholesome Drinking Water The law requires that water must be wholesome at the time of supply. Wholesomeness is defined by reference to drinking water quality standards and other requirements set out in The Water Supply (Water Quality) Regulations (Northern Ireland) 2007. These are available on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/public_water/regulations_ guidance.htm Many of these standards come from the 1998 European Drinking Water Directive which came fully into force on 25 December 2003. The Directive focuses on those parameters of importance to human health but it also includes others that relate to the control of water treatment processes and the aesthetic quality of drinking water. The Directive allows member states to set additional or tighter national standards to secure the good quality already achieved and to prevent it from deteriorating in the future. In the United Kingdom there are national specific definitions for wholesomeness of water at water treatment works, service reservoirs and in water supply zones.

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To be wholesome, water leaving a water treatment works must not contain: E. coli in excess of 0/100ml (national requirement);



l

l





l

coliform bacteria in excess of 0/100ml (national requirement); or nitrite in excess of 0.1 mgNO2 /l (Directive requirement).

To be wholesome, water leaving a service reservoir must not contain: l

l



E. coli in excess of 0/100ml (national requirement); or coliform bacteria in excess of 0/100ml in more than 5% of samples taken in a year (national requirement).

To be wholesome, water at consumers’ taps or water leaving a tanker must:

contain nothing alone (other than a parameter) or in combination (including parameters) that is a potential danger to public health (this is a catch-all provision which reflects the concept of wholesomeness as developed over the years);



meet the standards (maximum or minimum in Schedule 1, Tables A and B, i.e. Directive and national standards); and

l

l

l





satisfy the nitrate/nitrite formula (NO3 /50 + NO2/3 ≤ 1) (Directive requirement).

As can be seen, the concept of wholesomeness is based firmly on regulatory standards. However, what should be stressed is that unwholesome drinking water does not necessarily represent a risk to consumers’ health. Most standards are set with a very wide margin of safety and are based on a lifetime’s consumption of water.

Drinking Water Quality Standards The drinking water quality standards are set out in statute in The Water Supply (Water Quality) Regulations (Northern Ireland) 2007. Each regulated substance or organism is known as a parameter. As well as setting standards for each parameter, the Regulations state how often each one should be tested for and where the samples should be taken from. Samples are routinely collected at water treatment works, service reservoirs and customers’ taps. Anyone wishing to find out more about how each standard is derived can do so by accessing the published WHO expert opinion at: www.who.int/topics/drinking_water/en/

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Microbiological Standards To protect public health there are microbiological standards which have to be met at each treatment works and treated water service reservoir or tower. Microbiological determinations are also undertaken on consumer tap samples. The significance of individual test results for each microbiological parameter at each location varies, and a single positive result does not necessarily mean that water is unsafe to drink. Other information is required to assess water safety and each result is assessed on a case-by-case basis.

European Health-Based Chemical Standards European health-based standards for chemicals are set with a wide margin of safety on the basis of a lifetime’s consumption of water and taking into account the amounts present in food. Just because a standard has been set for a substance does not mean that it is present in drinking water. The vast majority of the regulated chemicals are never found in drinking water in Northern Ireland. Others occur only in very specific or local circumstances.

National Chemical and Physical Standards The European Drinking Water Directive recognizes the importance of maintaining a high quality of drinking water, and for this reason, several standards set in the original 1980 Drinking Water Directive (but not the 1998 Drinking Water Directive) have been continued in the form of national standards. Most of the standards address levels that make the water unacceptable to consumers on the grounds of odour, taste or appearance.

Additional Monitoring Parameters In addition to the drinking water standards, NI Water is required to test for additional indicator parameters to assist it with good water supply management and control of the drinking water quality. The Inspectorate’s website can be referenced to find out how each parameter complied with the regulatory standards: www.ni-environment.gov.uk/water/drinkwater/public_water/drinking_ water_quality.htm

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Water Testing NI Water has a duty to collect samples and test for each of the substances and organisms (known as parameters) in the Regulations. NI Water must make the results of this testing available to its customers. The Inspectorate’s role is to carry out independent checks to ensure that this testing is being performed to a high standard of quality control. Laboratories must be accredited and follow recognized methods of analysis such as those published by the Standing Committee of Analysts (SCAs) whose work is described below. The work of the Inspectorate is aimed at providing public reassurance regarding the robustness and the integrity of NI Water’s results. In Parts 1 and 2 of this report, the Inspectorate provides summaries of NI Water’s results for the benefit of consumers, businesses, district councils, health professionals and other regulators.

The Safety of Drinking Water The Regulations make some specific provisions for drinking water safety, for example, there are provisions regarding the parasite Cryptosporidium. There is also a requirement to adequately treat and disinfect water supplies, and there are controls over the chemicals and materials of construction that may be used in public water supplies. The Inspectorate carries out independent technical audits of NI Water’s records and sites to ensure that operational and management procedures are robust and appropriate.

What if Something Goes Wrong? NI Water is required by law to notify the Inspectorate of any event which may give rise to a significant risk to consumers’ health. Others, including consumers, can also make the Inspectorate aware of any such events. The Inspectorate will investigate and report on all these circumstances and, where necessary, initiate appropriate corrective action. Further information on events and incidents notified to the Inspectorate in 2007 can be found in Part 1, Table 1.13 of this report.

Standing Committee of Analysts NI Water is required to follow methods of analysis set within the Directive and the Regulations. National methods are published by the Standing Committee of Analysts. These documents are available free of charge and can be downloaded from the Environment Agency website at: www.environment-agency.gov.uk/nls

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Approval of Products for use in the Provision of Water Supplies The Drinking Water Inspectorate for England and Wales provides a technical resource to facilitate the approval, nationally, of chemicals and materials of construction. Until March 2007, this approval process was carried out by an independent expert committee, the Committee on Products and Processes. This committee was disbanded as part of the government’s ‘Better Regulation Process’ and replaced by the ‘Regulation 31 Enquiries Service’. For further information on the approval of products and for the current ‘List of Approved Products’, please refer to the Drinking Water Inspectorate for England and Wales website: www.dwi.gov.uk/31/approvedProducts.shtm

Drinking Water Science The safety of drinking water is of such importance to public health that the underpinning science is kept under continuous review. The World Health Organization manages a global process of rolling revision of drinking water guidelines on behalf of the water and health regulators in all countries (Guidelines for Drinking Water Quality, Third Edition). These guidelines can also be viewed on the WHO website: www.who.int/water_sanitation_health/dwq/guidelines/en/ All countries are able to contribute knowledge based on published peer review research studies and on data from their national water and health surveillance programmes.

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How to Find Out More about Drinking Water Quality If you want to find out about the quality of drinking water supplied to your home or workplace, then you should first contact NI Water at its Customer Service’s Unit: Tel: E-mail:

08457 440088 [email protected]

If you are researching a particular aspect of drinking water quality it is important to seek information from an appropriate source such as those listed below.

Drinking Water Inspectorate for Northern Ireland (DWI NI) The Drinking Water Inspectorate for Northern Ireland is a unit within the Northern Ireland Environment Agency, responsible for regulating the drinking water quality in Northern Ireland under The Water Supply (Water Quality) Regulations (Northern Ireland) 2007 and The Private Water Supplies Regulations (Northern Ireland) 1994. Web address: www.ni-environment.gov.uk/water/drinkwater.htm Tel: +44 (028) 9056 9282 E-mail: [email protected]

Drinking Water Inspectorate (DWI) England and Wales The Drinking Water Inspectorate (DWI) regulates public water supplies in England and Wales. It is responsible for assessing the quality of drinking water, taking enforcement action if standards are not being met, and appropriate action when water is unfit for human consumption. Web address: www.dwi.gov.uk Tel: +44 (0)207 270 3370 E-mail: [email protected]

Drinking Water Quality Regulator for Scotland (DWQR) The role of the Drinking Water Quality Regulator for Scotland was established in the Water Industry Act 2002 to provide an independent check that Scottish Water is complying with the Drinking Water Quality Regulations. Web address: www.dwqr.org.uk E-mail: [email protected]

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World Health Organization (WHO) The World Health Organization is the United Nations’ specialized agency for health. WHO’s objective is the attainment by all peoples of the highest possible level of health. Health is defined in WHO’s constitution as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Web address: www.who.int/water_sanitation_health/dwq/gdwq3rev/en/ index.html E-mail: [email protected]

Foundation for Water Research (FWR) An independent, non-profit-making organization, with charitable status, that shares and disseminates knowledge about water, wastewater and research into related environmental issues. Web address: www.fwr.org Tel: +44 (0)162 889 1589 E-mail: [email protected]

UK Water Industry Research (UKWIR) UKWIR facilitates collaborative research for UK water operators. The UKWIR programme generates sound science for regulation and practice. Web address: www.ukwir.co.uk Tel: +44 (0)207 344 1807 E-mail: [email protected]

Water UK Water UK is the industry association that represents all UK water and wastewater service suppliers at national and European level. Web address: www.water.org.uk/home Tel: +44 (0)207 344 1844

Water for Health Water for Health is a water industry initiative to guide and inform health authorities, to stimulate interest and research, and to help move water up the public agenda. Web address: www.water.org.uk/home/water-for-health Tel: +44 (0)207 344 1844

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Northern Ireland Environment Agency’s Water Management Unit (WMU) The Northern Ireland Environment Agency has a duty to promote the conservation of the water resources of Northern Ireland and the cleanliness of water in waterways and underground strata. WMU protects the aquatic environment. Web address: www.ni-environment.gov.uk/water/quality.htm Tel: +44 (028) 9262 3100 E-mail: [email protected]

Communicable Disease Surveillance Centre Northern Ireland (CDSC [NI]) The CDSC (NI) was established in 1999. The key elements of the service provided by CDSC (NI) include surveillance of communicable disease and research. It also provides advice and support to DHSSPS, Health and Social Services Boards and Trusts, and professionals. Web address: www.cdscni.org.uk Tel: +44 (028) 9026 3765 E-mail: [email protected]

Northern Ireland Authority for Utility Regulation (NIAUR) The Northern Ireland Authority for Utility Regulation has a responsibility to protect the interests of water and sewerage consumers with regard to price and quality of services, by promoting effective competition in the supply of water and the provision of sewerage services. Web address: http://ofreg.nics.gov.uk/ Tel: +44 (028) 9031 1575

Consumer Council for Northern Ireland The Consumer Council for Northern Ireland is a statutory body whose aims are to promote and safeguard the interests of all consumers in Northern Ireland. Web address: www.gccni.org.uk Tel: +44 (028) 9067 2488 E-mail: [email protected]

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Food Standards Agency Northern Ireland The Food Standards Agency is an independent government department set up by an Act of Parliament in 2000 to protect the public’s health and consumer interests in relation to food, including the use of water in food production. Web address: www.food.gov.uk/northernireland/ Tel: +44 (028) 9041 7700 E-mail: [email protected]

Drinking Water Quality and Health Research Programme Most research into drinking water quality and health is funded by the Department of the Environment, Food and Rural Affairs (DEFRA) in England. On behalf of DEFRA, the Drinking Water Inspectorate for England and Wales manages the national Drinking Water Quality and Health Research Programme (DWQH). The ‘Executive Summaries’ of the DWQH research reports, together with the reports by the former Department of the Environment and Department of the Environment, Transport and the Regions, since 1977, are posted on the Foundation for Water Research (FWR) website: www.fwr.org, with details of how to obtain copies of research reports. Some of the more recent DWQH reports are available in full on the Drinking Water Inspectorate for England and Wales website: www.dwi.gov.uk All enquiries about drinking water quality and research should be addressed in the first instance to: DWI Enquiries, Room M03, 55 Whitehall, London, SW1A 2EY, or e-mail: [email protected] A list of the research completed in 2007 and research in progress in 2008 is available from the Drinking Water Inspectorate for England and Wales website: www.dwi.gov.uk/research/researchindex.shtm .

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Annexes • Annex 1 - Glossary and Definition of Terms • Annex 2 - Roles and Responsibilities • Annex 3 - Drinking Water Quality Look-up Tables • Annex 4 - Calculations Used in the Report • Annex 5 - Authorised Departures • Annex 6 - Formal Notice Action • Annex 7 - Staffing

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Annex 1 - Glossary and Definition of Terms These definitions will assist in the understanding of the report where technical terms have been used.

Aesthetic

associated with the senses of taste, smell and sight.

AFBI

Agri-Food and Biosciences Institute, a non-departmental public body of the Department of Agriculture and Rural Development, created on 1 April 2006.

Aggressive

a term used to indicate that the water has a tendency to dissolve copper (and other metals) from the inner surface of a pipe or water fitting such as a tap.

Alkali

a solution containing an excess of free hydroxyl ions, with a pH greater than seven.

Analytical Quality Control (AQC)

Analytical Quality Control is the method used to ensure that laboratory analysis methods are performing correctly.

Aquifer

underground strata containing water.

Authorised Departure (AD)

authorisation granted by the Inspectorate, in consultation with the Health Authorities, for Northern Ireland Water Ltd to temporarily supply water exceeding a drinking water standard, provided that there is a planned programme of work at the water treatment works to improve the water quality and that there are no adverse health implications.

Authorised Supply Point

a sampling point within the distribution system authorised for certain parameters by the Inspectorate because the results of the analysis of such samples are unlikely to differ in any material respect from the results of the analysis of samples taken from consumers’ taps.

Catchment

the area of land that drains into a watercourse.

Chloramine

a substance formed by reaction between chlorine and ammonia, used as a disinfectant in distribution systems because it has long lasting properties compared to chlorine.

Chloramination

the process of generating a chloramine disinfectant residual in water leaving treatment works.

Chlorine Residual

the small amount of chlorine or chloramines present in drinking water to maintain its quality as it passes through Northern Ireland Water Ltd’s network of pipes and household plumbing.

Coagulation

a process employed during drinking water treatment to assist in the removal of particulate matter.

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Coliforms

a group of bacteria which may be faecal or environmental in origin.

Communication Pipe

the connection from the water main to the consumer property boundary (normally at the outside stop tap).

Compliance Assessment

a comparison made by the Inspectorate of data (gathered by Northern Ireland Water Ltd) against standards and other regulatory requirements.

Compound

a compound consists of two or more elements in chemical combination.

Contact Tank

a tank, normally situated on a water treatment works site, which forms part of the disinfection process. A disinfectant chemical (normally chlorine) is dosed into the water as it flows into the tank. The period of time that the water takes to flow through the tank allows sufficient ‘contact’ time for the chemical to kill or deactivate any viruses or pathogenic organisms that may be present in the water.

Contravention Cryptosporidiosis

a breach of the regulatory requirement.

Cryptosporidium

a protozoan parasite.

DEFRA

Department of the Environment, Food and Rural Affairs.

Determination

an analysis for a specific parameter.

Distribution Systems

Northern Ireland Water Ltd’s network of mains, pipes, pumping stations and service reservoirs through which treated water is conveyed to consumers.

Drinking Water Directive

European Council Directive (98/83/EC), relating to the quality of water intended for human consumption – setting out drinking water standards to be applied to member states.

Drinking Water Standards

the prescribed concentrations or values listed in the Regulations.

Epidemiology

a process of studying the distribution of cases of disease within a population in relation to exposure to possible sources of the infection, with a view to establishing the actual source of the infection.

Epoxy Resin Re-lining

a rehabilitation process in which a cleaned section of iron water main is sprayed with a mixture of epoxy resin and hardener to produce a thin but strong coating of material on the inside of the main.

Event

a situation affecting, or threatening to affect drinking water quality.

Exceedence

relates to a contravention or breach of regulatory standards.

Faecal Coliforms

a subgroup of coliforms, almost exclusively faecal in origin.

Filtration

the separation of suspended particulate matter from a fluid.

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the illness produced by infection with Cryptosporidium.

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Formal Notification

a process which commences with a ‘notice’ to Northern Ireland Water Ltd of the Inspectorate’s intention to initiate a formal process of notification documenting the Inspectorate’s requirements where a regulatory requirement has not been met.

Glyphosate

a broad-based spectrum herbicide used in both agriculture and forestry, and for aquatic weed control.

Granular Activated Carbon (GAC)

an absorbent filtration media used to remove trace organic compounds from water.

Groundwater

water from aquifers or other underground sources.

Incident

an event where there has been a demonstrable deterioration in the quality of drinking water.

Indicator Organism

an organism which indicates the presence of contamination and, hence, the possible presence of pathogens.

Indicator Parameter

something that is measured to check that the control measures, such as water treatment, are working effectively.

Inspectorate

the Drinking Water Inspectorate for Northern Ireland.

Investment Programme

investment in improvement works to water treatment works and distribution systems.

Leaching

to lose, or cause to lose soluble substances by the action of a percolating liquid.

Mains Rehabilitation

restoration of water mains pipework to a proper condition.

Mean Zonal Compliance % (MZC%)

a measure of compliance with drinking water standards - see zonal percentage compliance below.

MCPA

(4-chloro-2-methylphenoxy) acetic acid. An aryloxyalkanoic acid herbicide used for controlling broad-leaved weeds in grass or cereal crops.

MCPP

2-(4-chloro-2-methylphenoxy) propanoic acid. An aryloxyalkanoic acid herbicide used for controlling broad-leaved weeds in grass or cereal crops. Commonly referred to as Mecoprop.

Mecoprop

see MCPP.

Microbiological

associated with the study of microbes.

m3/d

cubic metres per day.

mg/l

milligrams per litre (one thousandth of a gram per litre).

ml

millilitre.

Ml/d

megalitres per day (one Ml/d is equivalent to 1,000 m3/d or 220,000 gallon/d).

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ng/l

nanograms per litre (one billionth of a gram per litre).

µg/l Notice of Intention

micrograms per litre (one millionth of a gram per litre).

Oocyst

the resistant form in which Cryptosporidium occurs in the environment, and which is capable of causing infection.

Organoleptic

characteristics of a substance detected by our senses, for example, taste, odour or colour.

Orthophosphoric Acid

a chemical which is added in low concentrations at water treatment works to minimize the uptake of lead from old pipework.

Ozone Process (Ozonation)

the application of ozone gas in drinking water treatment.

PAHs

a group of organic compounds known as Polycyclic Aromatic Hydrocarbons, comprising, for the purposes of the Regulations, four substances: benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi) perylene, and indeno(1,2,3-cd)pyrene.

Parameters

the substances, organisms and properties listed in Schedules 1 and 2, and regulation 2 of the Regulations.

Pathogen

an organism which causes disease.

Pentachlorophenol

a phenoxyacidic pesticide used primarily for protecting wood from fungal growth.

Pesticides

any fungicide, herbicide, insecticide or related product (excluding medicines) used for the control of pests or diseases.

pH Value

a measure of the acidity or basicity related to the concentration of the hydrogen ion.

Phosphate Dosing

treatment of water that results in a protective film building up on the inside of pipes, minimizing the likelihood of lead being present in drinking water supplied through lead pipes.

Plumbosolvency

the tendency for lead to dissolve in water.

Prescribed Concentration or Value (PCV) Private Water Supplies

the numerical value assigned to drinking water standards defining the maximal or minimal legal concentration or value of a parameter.

Protozoan Parasite

a single-celled organism that can only survive by infecting a host.

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a necessary precursor to the issue of a formal notice – see formal notification above.

any supplies of water provided otherwise than by the public supplier, Northern Ireland Water Ltd.

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Public Registers

the drinking water quality information made available to the public as required by the Regulations.

Public Supplies

water supplied by Northern Ireland Water Ltd.

Raw Water

water prior to receiving treatment for the purpose of drinking.

Regulations

The Water Supply (Water Quality) Regulations (Northern Ireland) 2007 (S.R. No.147, ISBN 978-0-337-96917), or, in the case of private water supplies, The Private Water Supplies Regulations (Northern Ireland) 1994 (S.R. No. 237, ISBN 0-337-912378). Remedial Action action taken to improve a situation. Residual Disinfectant

the small amount of chlorine present in drinking water to maintain its quality as it passes through Northern Ireland Water Ltd’s network of pipes and household plumbing.

Service Connection

connection between the Northern Ireland Water Ltd main to a consumer’s property.

Service Pipe

pipe that connects the consumer’s property to Northern Ireland Water Ltd’s main. It comprises two parts: the communication pipe which is the connection from the water main to the consumer’s property boundary (normally at the outside stop tap) and the supply pipe which runs from the boundary of the property to the consumer’s inside stop tap.

Service Reservoir

a water tower, tank or other reservoir used for the storage of treated water within the distribution system.

Supply Pipe

pipe connecting between the boundary of a consumer’s property to the inside stop tap.

Supply Point

a point, other than a consumer’s tap, authorised for the taking of samples for compliance with the Regulations.

Surface Water

untreated water from rivers, impounding reservoirs or other surface water sources.

Technical Audit

the means of checking that Northern Ireland Water Ltd is complying with its statutory obligations.

Time of Supply

the moment when water passes from Northern Ireland Water Ltd’s pipework into a consumer’s pipework.

Toxicology

the study of the health effects of substances.

Treated Water

water treated for domestic use as defined in the Regulations.

Trihalomethanes (THMs)

a group of organic substances comprising, for the purposes of the Regulations, four substances: trichloromethane (also known as chloroform), tribromomethane (also known as bromoform), dibromochloromethane and dichlorobromomethane.

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Water Supply Zone

a pre-defined area of supply for establishing sampling frequencies, compliance with standards and information to be made publicly available.

WHO

World Health Organization.

Wholesome/ Wholesomeness

a concept of water quality which is defined by reference to standards and other requirements set out in the Regulations.

WRc

Water Research Centre (1989) plc and/or, as the context may require, its predecessor body.

Zonal Percentage Compliance

the percentage of results for a specific parameter which complied with the PCV. The mean zonal percentage compliance is the average of the zonal percentage compliances of all water supply zones in a region.

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Annex 2 - Roles and Responsibilities Introduction In organizational terms, the Drinking Water Inspectorate for Northern Ireland is one of five functional units within the Environmental Protection Directorate of the Northern Ireland Environment Agency (NIEA), an executive agency within the Department of the Environment (DoE) in Northern Ireland. The agency is headed by a Chief Executive and a board of Directors which spans four directorates: Natural Heritage, Built Heritage, Environmental Protection, and Corporate Services. The Inspectorate’s staff are civil servants employed by the Crown. The Chief Inspector of Drinking Water is head of the functional unit. Following legislative changes under the Water and Sewerage Services (Northern Ireland) Order 2006 (‘the Order’), the Inspectorate, on 1 April 2007, became a statutory appointee acting on behalf of the Department for Regional Development (DRD) in respect of public drinking water supplies. The Inspectorate continues to act on behalf of the Department of the Environment in respect of private water supplies. The Order conferred, for the first time, enforcement powers on the Inspectorate in its dealings with Northern Ireland Water Ltd (NI Water). This change brings the Inspectorate ‘into line’ with other UK Drinking Water Regulators. The Inspectorate, in support of its role, has regular contact with health authorities, district councils, government departments, and other UK and EC Drinking Water Quality Regulators. Working relationships with the Northern Ireland Authority for Utility Regulation and the Consumer Council for Northern Ireland are being developed in conjunction with DRD Water Policy Division.

Statement of Functions Regulatory Functions The Inspectorate’s regulatory functions for public and private water supplies are contained within The Water Supply (Water Quality) Regulations (Northern Ireland) 2007 and The Private Water Supplies Regulations (Northern Ireland) 1994.

Other Functions The Inspectorate has responsibility for:

provision of advice and guidance to NI Water on all aspects of the regulatory requirements;



responding to enquiries relating to drinking water quality from consumers, organizations and businesses;

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Drinking Water Quality in Northern Ireland, 2007



provision of advice to Ministers on the Inspectorate’s operational matters, including advice on responses to Parliamentary Questions about those matters; and



provision of technical advice on drinking water issues, policies and standards to Ministers and officials in DRD and DoE.

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Participation in National, European and International Organizations

Working relationships with other UK Drinking Water Quality Regulators is managed within a Memorandum of Understanding.



Contact with member states of the European Union is made through a European Drinking Water Regulators’ Forum.



The Water Directorate (WD) within the Department of Environment, Food and Rural Affairs (DEFRA) has a seat on the EU Drinking Water Directive Article 12 Committee and DWI England and Wales attends as the ‘Technical Adviser’ to the WD. Currently the UK has one additional place available at the Article 12 Meeting. This place is available to the DWQR in Scotland and DWI (NI) on a rotational basis.

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Contacts with Other Organizations In conducting its business, the Inspectorate has regular contact with other organizations within Northern Ireland that have interests in, and responsibilities for various aspects of drinking water quality. Medical advice is obtained from the Chief Medical Officer of the Northern Ireland Department of Health, Social Services and Public Safety (DHSSPS). The Inspectorate liaises with the Chief Environmental Health Officer (also of DHSSPS) on relevant health matters and we also communicate with the Communicable Disease Surveillance Centre (Northern Ireland) and the Food Standards Agency. Regular contact with Environmental Health Officers in district councils continues in connection with both public and private drinking water quality matters. In maintaining and developing good communications between all these interested groups, an established Interdepartmental Drinking Water Liaison Group meets biannually to discuss and progress drinking water quality matters relevant in Northern Ireland.

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As a government-owned company, NI Water has financial, environmental and consumer accountability. The Inspectorate continues to develop working relationships with the other NI regulators: The Northern Ireland Authority for Utility Regulation, the ‘environmental regulator’ in the Northern Ireland Environment Agency, and the Consumer Council for Northern Ireland. The Inspectorate keeps itself informed of research being carried out and has representation on the DEFRA Drinking Water Quality and Health Research Programme Committee. The Inspectorate has regular contact with the Department of Agriculture and Rural Development (DARD) regarding private water supplies.

Information on Drinking Water in England and Wales, and Scotland Drinking water throughout the United Kingdom is subject to the same quality standards and similar Regulations are in place as to those applying in Northern Ireland. The Drinking Water Inspectorate for England and Wales acts for and on behalf of the Secretary of State for the Department for Environment, Food and Rural Affairs (DEFRA) and the National Assembly of Wales, in fulfilling its statutory duties in terms of drinking water quality in England and Wales. The Chief Inspector reports annually to the Secretary of State (DEFRA) and the National Assembly for Wales. Further information is available on the Inspectorate’s website: www.dwi.gov.uk Scottish Water, a publicly owned undertaker, is the sole supplier of public drinking water supplies in Scotland. Regulation is the responsibility of the Drinking Water Quality Regulator for Scotland who is appointed by Scottish Ministers to ensure that the drinking water quality duties imposed on the public water supplier are complied with. Further information on the Regulator’s activities can be obtained from its website: www.dwqr.org.uk The Inspectorate liaises closely with the other UK Regulators and operates in this respect with a publicly available Memorandum of Understanding which can be found on their respective websites. For the Drinking Water Inspectorate for Northern Ireland, this is available from: www.ni-environment.gov.uk/water/drinkwater.htm

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General Information about the Inspectorate General information is available to the public on our website at: www.ni-environment.gov.uk/water/drinkwater.htm

Complaints about the Inspectorate If a complaint is received about the way the Inspectorate handles or carries out its tasks, the Chief Inspector of Drinking Water will initiate an investigation of the issue and inform the complainant of the outcome of his investigation.

The Inspectorate’s Handling of Enquiries The Inspectorate received a range of general information enquiries from businesses and the general public during 2007. Where a written request for information was received, the Inspectorate replied within the 15 working days stipulated in the NIEA’s ‘Statements of Charter Standards’.

NIEA’s Customer Services Standards – Customer Charter The customer charter is available to download from the NIEA’s website: www.ni-environment.gov.uk/customer-charter.pdf

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Annex 3 - Drinking Water Quality Look-up Tables The following tables provide more detail of where the standards have not been met in the individual water supply zones. The tables present by parameter, all the contraventions that occurred in water supply zones and supply points at water treatment works during 2007.

Water Quality in Water Supply Zones, 2007 Table 3.1: % Mean Zonal Compliance - Aluminium

Sampling Location - Zones Number of compliant zones Z103, Ballinrees Z109, Dunore North Z110, Killylane Z112, Mormeal Z113, Moyola Z202, Altmore-Gortlenaghan Z221, Banbridge-Babylon Hill Z301, Ballyhanwood Z303, Breda East Z308, Downpatrick Z315, Lisnabreeny Z317, North Peninsula Z318, Oldpark Z322, Purdysburn North Z403, Carmoney Z404, Derg Z407, Killyhevlin Z410, Lough Braden Z413, Limavady Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

43 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 62

1,188 52 52 52 24 36 24 24 52 52 52 52 52 52 24 52 36 76 24 36 2,012

0 1 1 1 1 1 2 1 1 1 6 3 1 1 1 3 1 1 2 1 30

100.00 98.08 98.08 98.08 95.83 97.22 91.67 95.83 98.08 98.08 88.46 94.23 98.08 98.08 95.83 94.23 97.22 98.68 91.67 97.22

98.78

Table 3.2: % Mean Zonal Compliance - Colour Sampling Location - Zones Number of compliant zones Z219, Seagahan Z413, Limavady Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

60 1 1 62

1,940 36 36 2,012

0 1 1 2

100.00 97.22 97.22

99.91

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Table 3.3: % Mean Zonal Compliance - E. coli Sampling Location - Zones Number of compliant zones Z108, Dungonnell Z201, Altmore Z209, Castor Bay-Shanmoy Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

59 1 1 1 62

5,449 48 12 59 5,568

0 1 1 1 3

100.00 97.92 91.67 98.31

99.80

Table 3.4: % Mean Supply Point Compliance - Heptachlor Epoxide Sampling Location Supply Points Number of compliant supply points W3301, Dunore Point Total number of supply points Mean Supply Point Compliance

Number of Supply Points 42 1 43

Number of Samples 364 24 388

Number of Tests >PCV per Supply Point 0 1 1

% Supply Point Compliance 100.00 95.83 99.90

Table 3.5: % Mean Zonal Compliance - Hydrogen Ion <6.5 Sampling Location - Zones Number of compliant zones Z307, Dorisland Total number of zones Mean Zonal Compliance

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Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

61 1 62

1,936 76 2,012

0 1 1

100.00 98.68

99.98

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Sampling Location - Zones Number of compliant zones Z102, Altnahinch Z103, Ballinrees Z104, Ballymena Borough Z109, Dunore North Z110, Killylane Z112, Mormeal Z113, Moyola Z202, Altmore-Gortlenaghan Z212, Fofanny-Banbridge Z214, Lough Ross Z219, Seagahan Z225, Newry-Ballintemple Z302, Ballysallagh Z305, Clandeboye Z307, Dorisland Z308, Downpatrick Z310, Dunore East Z319, Purdysburn South Z322, Purdysburn North Z403, Carmoney Z410, Lough Braden Z413, Limavady Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

40 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 62

1,164 36 52 36 52 52 24 36 24 24 24 36 24 24 52 76 52 52 36 24 52 24 36 2,012

0 1 1 1 1 1 1 1 5 1 4 2 1 1 1 3 1 1 1 1 1 2 2 34

100.00 97.22 98.08 97.22 98.08 98.08 95.83 97.22 79.17 95.83 83.33 94.44 95.83 95.83 98.08 96.05 98.08 98.08 97.22 95.83 98.08 91.67 94.44

98.29

Sampling Location - Zones Number of compliant zones Z210, Clay Lake Z304, Breda West Z306, Conlig Z408, Lenamore Springs Total number of zones Mean Zonal Compliance

Table 3.6: % Mean Zonal Compliance - Iron

Table 3.7: % Mean Zonal Compliance - Lead

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

58 1 1 1 1 62

440 8 8 4 4 464

0 1 1 1 1 4

100.00 87.50 87.50 75.00 75.00

98.79

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Table 3.8: % Mean Zonal Compliance - Manganese Sampling Location - Zones Number of compliant zones Z103, Ballinrees Z112, Mormeal Z113, Moyola Z202, Altmore-Gortlenaghan Z210, Clay Lake Z219, Seagahan Z221, Banbridge-Babylon Hill Z223, Lurgan-Magheraliskmisk Z301, Ballyhanwood Z303, Breda East Z305, Clandeboye Z307, Dorisland Z313, Lisbane Z315, Lisnabreeny Z317, North Peninsula Z319, Purdysburn South Z322, Purdysburn North Z403, Carmoney Z410, Lough Braden Z413, Limavady Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

42 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 62

1,220 52 24 36 24 12 36 24 52 52 52 52 76 24 52 52 36 24 52 24 36 2,012

0 1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 2 23

100.00 98.08 95.83 97.22 91.67 91.67 97.22 95.83 98.08 98.08 98.08 98.08 98.68 95.83 96.15 98.08 97.22 95.83 98.08 95.83 94.44

98.87

Table 3.9: % Mean Zonal Compliance - Nickel

Sampling Location - Zones Number of compliant zones Z107, Drumabest Total number of zones Mean Zonal Compliance

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Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

61 1 62

456 8 464

0 1 1

100.00 87.50

99.80

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Table 3.10: % Mean Supply Point Compliance - Pesticides - Other Substances Sampling Location Supply Points

Number of Supply Points

Number of Samples

Number of compliant supply points W2501, Altmore W3317, Dorisland W4501, Derg Total number of supply points Mean Supply Point Compliance

40 1 1 1 43

17,432 8 12 8 17,460

Number of Tests >PCV per Supply Point 0 1 2 1 4

% Supply Point Compliance 100.00 87.50 83.33 87.50 99.03

Table 3.11: % Mean Supply Point Compliance - Pesticides - Total Substances Sampling Location Supply Points

Number of Supply Points

Number of Samples

Number of compliant supply points W2501, Altmore Total number of supply points Mean Supply Point Compliance

42 1 43

380 8 388

Number of compliant zones Z101, Alcrossagh Z102, Altnahinch Z103, Ballinrees Z104, Ballymena Borough Z106, Buckna Z109, Dunore North Z110, Killylane Z112, Mormeal Z113, Moyola Z201, Altmore Z202, Altmore-Gortlenaghan Z209, Castor Bay-Shanmoy Z210, Clay Lake Z219, Seagahan Z221, Banbridge-Babylon Hill Z222, Ballydougan-Ballyhannon Z223, Lurgan-Magheraliskmisk Z225, Newry-Ballintemple Z227, Castor Bay-Richill

% Supply Point Compliance 100.00 87.50 99.71

Sampling Location - Zones

Number of Tests >PCV per Supply Point 0 1 1

Table 3.12: % Mean Zonal Compliance - Trihalomethanes Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

28 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

188 8 8 8 24 4 24 8 12 24 12 12 12 12 24 12 36 24 12 12

0 1 3 3 5 1 4 5 2 7 4 5 8 12 23 6 20 13 2 8

100.00 87.50 62.50 62.50 79.17 75.00 83.33 37.50 83.33 70.83 66.67 58.33 33.33 0.00 4.17 50.00 44.44 45.83 83.33 33.33

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Table 3.12: Continued Sampling Location - Zones Z302, Ballysallagh Z303, Breda East Z304, Breda West Z309, Dunmurry Z310, Dunore East Z311, Holywood Z314, Lisburn North Z316, Lough Cowey Z318, Oldpark Z319, Purdysburn South Z320, Stoneyford Z321, Woodvale Z403, Carmoney Z404, Derg Z409, Foyle Z410, Lough Braden Z413, Limavady Total number of zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 62

8 24 8 24 36 12 12 12 36 8 12 36 8 8 8 12 12 752

3 3 2 21 16 9 9 1 11 1 6 16 1 4 2 3 3 243

62.50 87.50 75.00 12.50 55.56 25.00 25.00 91.67 69.44 87.50 50.00 55.56 87.50 50.00 75.00 75.00 75.00

79.37

Table 3.13: % Mean Zonal Compliance - Turbidity Sampling Location - Zones Number of compliant zones Z112, Mormeal Z307, Dorisland Z322, Purdysburn North Z403, Carmoney Total number of zones Mean Zonal Compliance

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Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

58 1 1 1 1 62

1,848 22 72 22 48 2,012

0 1 2 1 1 5

100.00 95.45 97.22 95.45 97.92

99.77

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Water Quality Leaving Water Treatment Works, 2007 The following tables give a summary of the quality of water leaving water treatment works.

Table 3.14: Quality of Water Leaving Water Treatment Works European Directive Standards Parameter Nitrite (works) TOTAL

Prescribed Concentration or Value 0.1 mgNO2/l

Total Number of Tests 387 387

Number of Tests Failed 0 0

% of Tests Failed 0.00 0.00

Number of Works with Failures 0

0

Table 3.15: Quality of Water Leaving Water Treatment Works National Standards Parameter Coliform bacteria E. coli TOTAL

Prescribed Concentration or Value 0/100ml 0/100ml

Total Number of Tests 9,471 9,471 18,942

Number of Tests Failed 11 4 15

% of Tests Failed 0.12 0.04 0.08

Number of Works with Failures 9 4

Table 3.16: Quality of Water Leaving Water Treatment Works Additional European Monitoring Requirements

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Table 3.17: Quality of Water Leaving Water Treatment Works Northern Ireland Requirement

Parameter Cryptosporidium oocysts TOTAL

Reporting Value

Total Number of Tests

<1 oocysts per 10 litres

Number of Tests

% of Tests Reported

Number of Works Reported

130

0

0.00

1*

130

0

0.00

>1 Oocysts/100mls

*Continuous monitoring at one water treatment works assessed at being at risk, out of a total of 43 water treatment works.

Water Quality Sampling The Regulations set out sampling requirements for a range of parameters to be sampled from specific locations. The Inspectorate notes that for 2007 there was a significant improvement towards overall compliance with the regulatory sampling frequency requirements. Where this has not been achieved, the Inspectorate requires NI Water to continue to ensure that a robust sampling programme is in place to enable a target of full compliance to be met. The integrity of monitoring results is fundamental to everyone wanting to know and understand about drinking water quality.

Table 3.18: Summary of Non-Trivial Sampling Shortfalls Number of Water Supply Zones 62

Number of Water Treatment Works 43

Number of Service Reservoirs 342

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Water Supply Zones with Sampling Shortfalls Number 10

% 15.15

Water Treatment Works with Sampling Shortfalls Number 7

% 14.58

Service Reservoirs with Sampling Shortfalls Number 0

% 0.00

Water Supply Zones with Non-Trivial Sampling Shortfalls Number 3

% 4.35

Water Treatment Works with Non-Trivial Sampling Shortfalls Number 0

% 0.00

Service Reservoirs with Non-Trivial Sampling Shortfalls Number 0

% 0.00

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Annex 4 - Calculations Used in the Report Meeting the Standards Mean zonal compliance (MZC%) is an index used by Drinking Water Quality Regulators throughout the United Kingdom to assess water quality compliance at consumers’ taps. The background to this approach can be referenced in the Drinking Water Quality in Northern Ireland, 2004 report which is available on the Inspectorate’s website: www.ni-environment.gov.uk/water/drinkwater/annual_reports.htm The mean zonal compliances comprised the average of the MZC% figures for 40 different parameters that are tested to establish the quality of water. The parameters combining to form this index are listed in Table 4.2.

Definitions Mean Zonal Compliance for a Parameter For any one zone, the zonal compliance for any parameter is: •

the percentage of samples meeting the PCV.

Interpretation of Supply Point Samples Each supply point is viewed as though it was another zone in Northern Ireland and ‘supply point compliance’ is calculated in exactly the same way as zonal compliance. Mean Zonal Compliance for all Parameters For any parameter, mean zonal compliance (MZC%) is defined as: •

the arithmetic mean of the zonal compliance values for any specified group of zones (e.g. a group such as the 62 zones specified by NI Water for 2007).

For those parameters that are monitored at a mixture of supply points and zones, it would be too cumbersome to refer to ‘mean zonal and/or supply point compliance’. In all that follows, therefore, the term ‘mean zonal compliance’ will be taken to mean: •

the arithmetic mean of the zonal compliance values for any specified group of zones and/or supply points.

The specific grouping of particular interest is: •

all zones in Northern Ireland.

The detailed MZC% calculations for this grouping are illustrated by detailed worked examples in the following sections.

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Mean Zonal Compliance for Northern Ireland Consider the example of the parameter colour. The zonal compliance results for the 62 sampling locations (water supply zones) are summarized below.

Table 4.1: Calculation of % Mean Zonal Compliance for Colour

Sampling Location Number of compliant zones Z219, Seagahan Z413, Limavady Total Number of Zones Mean Zonal Compliance

Number of Zones

Number of Samples

Number of Tests >PCV per Zone

% Zonal Compliance

60 1 1 62

1,940 36 36 2,012

0 1 1 2

100.00 97.22 97.22

The values are 100% in all but two zones. The sum of the 62 zonal compliance values is 6,194.44, and so the mean zonal compliance for colour is the sum of the MCZ calculation which provides the numerator of the calculation, divided by the number of zones: 6,194.44/62 = 99.91%.

Overall Compliance Definitions For any specified collection of zones and/or supply points, the overall compliance is: • the arithmetic mean of the mean zonal compliance values for all parameters defined in Table 4.1 of this annex. The arithmetic mean is used in order to give all 40 parameters equal weight in the overall figure.

Overall Compliance for Northern Ireland The detailed calculation of MZC% for colour has already been described, and so it is convenient to continue with this for Northern Ireland as a worked example. Overall, NI Water monitored for 40 parameters at zones and/or supply points during 2007. Of these, 27 had a mean zonal compliance of 100%; the MZC% values for the other 13 parameters are highlighted in Table 4.2.

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99.91

Numerator of MZC Calculation 6,000 97.22 97.22 6,194.44

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Table 4.2: Parameters used in the Calculation of Mean Zonal Compliance Parameter Colour Turbidity Odour Taste Hydrogen ion Sodium Nitrate Nitrite Nitrate/nitrite formula Aluminium Iron Manganese Copper Fluoride Arsenic Cadmium Cyanide Chromium Mercury Nickel Lead Antimony Selenium Pesticides - total substances PAH - sum of 4 substances E. coli Enterococci Boron Benzo(a)pyrene Tetrachloromethane Tetrachloroethene/trichloroethene (sum of 2 substances) Total trihalomethanes 1,2-dichloroethane Benzene Bromate Aldrin Dieldrin Heptachlor Heptachlor epoxide Pesticides - other substances* Total Number of Samples Mean Zonal Compliance %

Point of Compliance Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps (samples taken at works not included) Calculated from samples taken at consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Consumers’ taps Supply point or consumers’ taps Consumers’ taps Consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Consumers’ taps Consumers’ taps (samples taken at works/reservoirs are not included) Consumers’ taps Supply point or consumers’ taps Consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps Supply point or consumers’ taps

Number of Samples

% Zonal Compliance

2,012 2,012 2,012 2,012 2,012 464 492

99.91 99.77 100 100 99.98 100 100

492

100

492

100

2,012 2,012 2,012 464 387 464 464 388 464 388 464 464 464 464 388 464

98.78 98.29 98.87 100 100 100 100 100 100 100 99.80 98.79 100 100 99.71 100

5,568

99.80

464 388 464 388

100 100 100 100

388

100

752 388 388 464 388 388 388 388 17,460 52,427

79.37 100 100 100 100 100 100 99.90 99.03 99.30

*All pesticides other than aldrin, dieldrin, heptachlor and heptachlor epoxide. 117

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The ‘overall compliance’ for Northern Ireland is then calculated as the simple arithmetic mean of these 40 MZC% values, namely 99.30%.

Pesticides - Other Substances NI Water carries out a great deal of pesticide monitoring. However, the specific number and types of pesticides vary depending on the monitoring programme implemented by the various water undertakers in the United Kingdom, so a method is needed not only to standardize the results for comparative purposes, but also to avoid attaching too much weight to the MZC% values for the many individual pesticides. The method adopted is to pool the results for all pesticides other than aldrin, dieldrin, heptachlor and heptachlor epoxide, and to treat them as a single ‘other pesticides’ parameter. A worked example of how to calculate this is given below.

Table 4.3: % Mean Zonal Compliance, Pesticides - Other Substances Sampling Location Supply Points Number of compliant zones W1301, Moyola W2706, Camlough W3317, Dorisland W4301, Carmoney W4541, Glenhordial Total Number of Zones Mean Zonal Compliance

Number of Supply Points 43 1 1 1 1 1 48

Number of Samples* 15,520 320 320 480 320 320 17,280

Number of Tests >PCV per Supply Point 0 1 1 2 2 1 7

% Zonal Compliance

* Samples: Each individual pesticide is considered to be a sample, e.g. if 8 sample bottles were collected during the year and analyzed on each occasion for 40 individual pesticides, then the number of samples reported for that supply point would be 8 x 40 = 320. For each site, every occasion where any individual pesticide is reported >0.1 µg/l, this will be entered in the Number of Tests >PCV per Supply Point column: e.g. Dorisland had >0.1 µg/l on two separate sampling occasions for MCPA; and for Carmoney, two individual pesticides had >0.1 µg/l for glyphosate and mecoprop. (Example calculated using 2005 data.)

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100.00 99.69 99.69 99.58 99.38 99.69

99.96

Numerator of MZC Calculation 4,200 99.69 99.69 99.58 99.38 99.69 4,698.02

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Drinking Water Quality in Northern Ireland, 2007

The Operational Performance Index (OPI [TIM]) Definition For any specified collection of zones, the OPI (TIM) is defined as: •

the arithmetic mean of the mean zonal compliance values for a defined subset of parameters: turbidity, iron and manganese.

An example of this is shown in the table below which lists mean zonal compliance values for turbidity, iron and manganese for all of the water supply zones in Northern Ireland. The derivation of each of the two MZC% values for colour has been shown in Table 4.1. The sets of values for turbidity, iron and manganese are calculated similarly. Once the MZC% values have been determined for the three component parameters, the OPI (TIM) index is simply calculated as the arithmetic mean of the three components as shown in the table below.

Table 4.4: Calculation of OPI (TIM) Mean Zonal Compliance

Parameter

% Mean Zonal Compliance

Turbidity Iron Manganese OPI (TIM)

99.77 98.29 98.87 98.98

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120

Zone Name

Ballymena Borough

Dunore North Dunore East

Oldpark

Woodvale Mormeal Moyola Unagh

Castor Bay-Shanmoy

Banbridge-Babylon Hill Ballydougan-Ballyhannon

Lurgan-Magheraliskmisk

Newry-Ballintemple

Castor Bay-Richill

Clay Lake

Zone Code

Z104

Z109 Z310

Z318

Z321 Z112 Z113 Z116

Z209

Z221 Z222

Z223

Z225

Z227

Z210

Clay Lake

Dunore Point, Dungonnell, Buckna Borehole Dunore Point Dunore Point Dunore Point, Dorisland, Drumaroad Dunore Point, Drumaroad Moyola, Lough Fea Moyola Moyola, Lough Fea Castor Bay, Shanmoy Borewell Castor Bay Castor Bay Castor Bay, Forked Bridge/ Lagan Valley Boreholes at Poleglass Castor Bay, Camlough, Fofanny Castor Bay, Seagahan

WTWs Supplying Water Supply Zone

150

150

150

150

150 150

150

150 150 150 150

150

150 150

150

THMs AD Value µg/l

10,000

1,800

23,900

53,400

26,600 78,000

21,600

91,100 11,200 35,800 15,100

75,200

66,860 79,402

40,800

Population

AD End Date

30 November 2007

24 September 2009

24 September 2009

24 September 2009

24 September 2009 24 September 2009

24 September 2009

15 October 2009 16 July 2009 16 July 2009 16 July 2009

15 October 2009

15 October 2009 15 October 2009

15 October 2009

Table 5.1: 2007 Authorised Departures (ADs) for THMs and Associated Improvement Schemes

Clay Lake WTWs upgrade completed June 2008.

Castor Bay WTWs upgrade started June 2006; completion expected October 2008.

Moyola WTWs upgrade completed September 2008.

Dunore Point WTWs upgrade started June 2006; completion expected October 2008.

Progress with WTWs Compliance Measures

The information contained in the following tables lists by water supply zone, the water treatment works (WTWs) supplying the zone and a summary of the associated Authorised Departure compliance improvement schemes which the Inspectorate has agreed with NI Water.

Annex 5 - Authorised Departures

Drinking Water Quality in Northern Ireland, 2007 www.ni-environment.gov.uk

Dunmurry

Lisburn North

Stoneyford Altmore

Altmore-Gortlenaghan

Seagahan

Holywood

Lough Cowey

Lough Braden

Z309

Z314

Z320 Z201

Z202

Z219

Z311

Z316

Z410

Lough Bradan

150

150

150

Creightons Green, Drumaroad

Lough Cowey

150

150

16,700

7,700

4,200

39,000

19,700

5,900 2,000

18,100

150 150 150

61,000

150

Seagahan

Altmore, Gortlenaghan Borewell

Forked Bridge/Lagan Valley Boreholes at Poleglass, Drumaroad Forked Bridge/Barbour Boreholes at Northern Forked Bridge Altmore

30 November 2010

24 December 2009

31 October 2008

24 December 2009

24 December 2009

24 September 2009 24 December 2009

24 September 2009

24 September 2009

Seagahan WTWs upgrade interim work to be completed by September 2008, with final upgrade to be completed by December 2009. Creightons Green WTWs to be decommissioned by December 2008 and Drumaroad WTWs to supply the area. Lough Cowey WTWs was decommissioned in October 2008. Drumaroad WTWs is now supplying the area. Lough Bradan WTWs upgrade work will begin in November 2008; completion expected November 2009.

Altmore WTWs to be decommissioned following network upgrade. Completion date expected by 2009/2010.

Link main to supply Forked Bridge WTWs with water from Castor Bay WTWs started September 2006; completion expected October 2008.

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Table 5.2: 2007 Authorised Departures (ADs) for Pesticides and Associated Improvement Schemes

Zone Code

Zone Name

WTWs Supplying Water Supply Zone

Z201

Altmore

Altmore

Z202

AltmoreGortlenaghan

Altmore, Gortlenaghan Borewell

Z316

Lough Cowey

Lough Cowey

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Mecoprop AD µg/l

MCPA AD µg/l

Population

AD End Date

0.5

2,000

24 December 2009

19,700

24 December 2009

7,700

24 December 2009

0.5

0.3

Progress with WTWs Compliance Measures Altmore WTWs to be decommissioned following network upgrade. Expected completion date by 2009/2010. Lough Cowey WTWs was decommissioned in October 2008. Drumaroad WTWs is now supplying the area.

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Drinking Water Quality in Northern Ireland, 2007



Annex 6 - Formal Notice Action

Table 6.1: Formal Notice Action Summary Details

Date

Parameter

Location

January - April 2006

Trihalomethanes (THMs)

Clay Lake Water Supply Zone

Recurring THM contraventions. (Ongoing into 2007.)

Authorised Departure granted while water treatment upgrade work is carried out at Clay Lake Water Treatment Works which supplies this area. Upgrade was completed in June 2008.

April 2005 March 2006

Iron

Limavady Water Supply Zone

Recurring iron contraventions due to cast-iron water mains. (Ongoing into 2007.)

Further investigation and survey of water mains in the area. Interim flushing programme. Longer term action will be for water mains rehabilitation to be undertaken, started in January 2008.

March August 2006

THMs

Killylane Water Supply Zone

Recurring THM contraventions. (Ongoing into 2007.)

Review of chlorination practice; review use of blending with Dunore Point water supply; and optimization of the water treatment processes required for Killylane Water Treatment Works.

July - August 2006

Coliform bacteria

Corlea Service Reservoir

Recurring coliform contraventions.

Review of chlorination practice. Self-contained sodium hypochlorite dosing unit commissioned and operational in April 2007.

May - August 2006

Coliform bacteria

Derrylin Service Reservoir

Recurring coliform contraventions. (Ongoing into 2007.)

Review of chlorination practice. Self-contained sodium hypochlorite dosing unit commissioned and operational in May 2007. 99

August September 2006

THMs

Lough Braden Water Supply Zone

Recurring THM contraventions. (Ongoing into 2007.)

Review of chlorination practices at Lough Bradan Water Treatment Works. Authorised Departure granted while water treatment process refurbishment and commissioning is undertaken. Construction work to start in September 2009.

E. coli and coliform bacteria

Trienaltenagh Service Reservoir

Recurring E. coli and coliform contraventions.

Review of chlorination practice. Inspection of service reservoir; ingress identified. Hypochlorite dosing unit to be installed. This service reservoir is included in NI Water’s service reservoir integrity programme of remedial work.

September October 2006

Details

Corrective Action

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Drinking Water Quality in Northern Ireland, 2007

Table 6.1: Continued

Date

Parameter

Location

Details

Corrective Action

June September 2006

Coliform bacteria

Drumharvey Service Reservoir

Recurring coliform contraventions.

Review of chlorination practice. Inspection of service reservoir; ingress identified. Hypochlorite dosing unit to be installed. Temporary chlorination in place.

February October 2006

Coliform bacteria

Loughans Service Reservoir

Recurring coliform contraventions. (Ongoing into 2007.)

Investigatory work carried out; temporary chlorination in place. This service reservoir was taken out of supply in December 2007.

September October 2006

Coliform bacteria

Ballyberidagh Service Reservoir Altmore Water Treatment Works

Recurring coliform contraventions.

Temporary chlorination in place. This service reservoir was taken out of supply in December 2007. Liaison with Northern Ireland Environment Agency’s Pollution Prevention Section, and Forestry Service to investigate any potential catchment activities. Water treatment works process review; particulate activated carbon dosing system is installed. This treatment works is to be decommissioned in 2009.

Coagh Service Reservoir

Recurring coliform contraventions.

August October 2006

October 2006

124

MCPA and total pesticides

Coliform bacteria

Recurring MCPA contraventions. (Ongoing into 2007.)

Hypochlorite dosing unit to be installed. This service reservoir is included in NI Water’s service reservoir integrity programme of remedial work.

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Drinking Water Quality in Northern Ireland, 2007

Annex 7 - Staffing In organizational terms, the Inspectorate is one of five functional units within the Environmental Protection Directorate of the Northern Ireland Environment Agency (NIEA), an executive agency within the Department of the Environment in Northern Ireland. The agency is headed by a Chief Executive and a board of Directors which spans four directorates: Natural Heritage, Built Heritage, Environmental Protection and Corporate Services.

Staff A list of Inspectorate staff in post during 1 January 2007 to 30 June 2008 is given below.

Chief Inspector

Randal Scott

Senior Inspector

Margaret Herron

Senior Inspector

David O’Neill

Senior Inspector

Colin Clements

Higher Scientific Officer

Una Mailey

Higher Scientific Officer

Bernadette Corr

Scientific Officer

Paddy Griffin

Administrative Officer

Claire Shields

Casual Administrative Assistant

Aaron Tedford

Casual Administrative Assistant

Gareth Haddock

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Drinking Water Quality in Northern Ireland, 2007

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Drinking Water Inspectorate for Northern Ireland Environmental Protection Northern Ireland Environment Agency Klondyke Building Cromac Avenue Gasworks Business Park Belfast BT7 2JA T. 028 9056 9282 - F. 028 9056 9263 E: [email protected]

Our aim is to protect, conserve and promote the natural and built environment for the benefit of present and future generations.

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