Water Sanitation

Water Sanitation Maribel U. Cruz , M.D.

Session Objectives 1.

2. 3.

4. 5.

To discuss the situation regarding accessibility to safe water supply in the Philippines To enumerate the National Objectives for health in relation to water sanitation To compare the sources of water supply in terms of quality, quantity & usual points of contamination To differentiate the physical, chemical & bacteriological characteristics of water To enumerate & discuss the approved types of water supply

1.

2. 3.

4.

To discuss the processes involved in the standard water treatment of a public water supply To discuss the different household methods of water treatment To enumerate the different protective measures as provided under the Water Code of the Philippines To discuss the monitoring scheme of the government to ensure a safe public water supply system

Situationer ► Households

with access to safe drinking water have increased for both urban and rural households ► The proportion of HH within 15 min. from water supply facilities increased from 86.2% in 1998 to 87% in 2003 (NDHS) ► The proportion of HH with water supply coming from safe sources increased from 81.7% in 1998 to 89.3% in 2003

Situationer ► Piped

water supply into dwelling, plot or yard increased from 36.8% in 1998 to 39.6% in 2003 ► In urban towns outside of MM, piped water supply coverage increased from 77.6% in 1998 to 88.1% in 2000 ► In MM as a result of privatization of the water distribution system, the service coverage by the 2 concessionaires increased from 67% in 1997 to 90% in 2001

Distribution of Sources of Drinking Water of Households, BSNOH 2000 N MWSS Community faucet Private faucet Bottled water Open dug well Water Tanker Rain , Spring, Streams

Urban 1510 46.0 39.0 7.7 4.8 1.9 4.8 1.9

Rural Total 1193 2703 7.3 43.0 47.5 39.6 21.0 8.8 0.4 4.5 6.8 2.2 0.5 0.4 20.2 3.3

Situationer No. of households with access to safe water in the City of Manila in 2004 Total No. of HH – 304,114 Level I – none Level II - 33,453 (11%) Level III - 270, 661 ( 89%)

Accessibility to Safe Water Supply ► Provinces

with the highest coverage: Southern Leyte, Rizal, Pangasinan, Cavite, and Surigao del Norte

► Lowest

coverage: Zamboanga Sibugay, Sulu, Masbate, Batangas and Pampanga

► Regions

who have achieved >90% coverage of HH: CAR, Ilocos &

Environmental Health ►

Goal : Environmental health conditions in the country are improved Morbidity and Mortality from environmental health hazards are reduced

National Objectives 20052010 Household access to safe water is increased 1. Indicator : Percentage of HH with access to safe water (at national level, urban and rural areas  Target: 94% national; 98% urban; 90% rural  Baseline: 89.3% national; 96.1%

National Objectives 20052010 2. Indicator: Percentage of HH with doubtful water sources practicing boiling and chlorination to make water safe for drinking  Target: more than 27% (boiling) more than 1.7% (chlorination)  Baseline : 27% boiling ; 1.7%

► Water

Storage 89% of urban and 69% of rural respondents used plastic containers with cover 30% rural respondents used clay jars with cover About 7% of urban and 5% of rural respondents put their drinking water in a glass with no cover

Sources of Water A.

Surface Water Derived from streams, brooks, lakes, ponds and rivers Accessible to communities and are of sufficient quantity Subject to seasonal variability Always contaminated by surface run-off Frequently polluted by uncontrolled disposal of human excreta, domestic & industrial wastes

A.

Ground Water Obtained from wells & springs Largest source of water Untreated, non-saline ground water is biologically pure from organisms



Wells – structure that is dug, driven, bored or drilled into the ground for the purpose of securing water

Dug & driven wells – usually confined to soft ground, sand & gravel to a depth of less than 100 ft. Bored & drilled wells – used in hard ground or rock & maybe sunk in depths hundreds or thousands of feet Deep wells – generally greater than 100 ft. in depth and drilled Pollution of wells can result from seepage of organic , industrial and



Spring – ground water seepage which is created when the level of underground water comes in contact with the surface usually at the side of a hill or mountain Contamination of spring water occurs at the point of seepage since surface water may join the spring flow at that

Sources of Water 1.

Rainwater Basically free from impurities Contamination may occur at the collection and storage points

Public Water Supply System ► 2. 4. 6.

9.

Components Collection works – dams, reservoirs, pumps Transportation works – conduits, aqueducts, & main transmission pipes Treatment works - chemical dosing plants, mixing & flocculation tanks, disinfection equipment Distribution works – mains & laterals, pumping machinery

Characteristics of Water Physical 2. Chemical 3. Biological 4. Radiological 1.

Physical Characteristics ► Water

for drinking & household use should be clear, odorless and tasteless ► Turbidity is caused by impurities in suspension. Can be reduced by coagulation, sedimentation and rapid sand filtration ► Color is due to substances in solution ► Odor is removed by aeration, chlorination & adding activated carbon ► Water is most palatable at 50-60 degree F

Chemical Characteristics ► Ground

water has a ph range of 5.9-9.0 ► Hardness – soap consuming property or power of water Temporary – due to carbonates Permanent – due to chlorine, calcium and magnesium salts  Water for drinking & household use should preferably not contain chemical substances in concentrations beyond acceptable limits as defined in the National Standards for Drinking Water

Philippine National Standards for Drinking Water ► Calcium

– 75 mg/L ► Chloride – 2000mg/L ► Mg – 50 mg/L ► Nitrate – 30 mg/L ► Oil & grease – nil ► Ph – 6.5 – 8.5 ► Sulfate – 200 mg/L ► Phenol – 0.001 mg/L

► Arsenic

– 0.05 mg/L ► Barium – 1.0 mg/L ► Copper – 1.0 mg/L ► Cyanide – 0.05 mg/L ► Fluoride - .6 – 1 mg/L ► Iron – 1.0 mg/L ► Lead – 0.05 mg/L ► Mercury - 0.002 mg/L

Biological Characteristics ► Biological

Examination – determines the kind & amount of microscopic life present in the water ► Responsible for the taste & odor of water ► Presence of biological impurities serve as an index of the degree of pollution of the water

Biological Characteristics ► Bacteriological

Examination – determines whether or not the kind & number of bacteria present in the water constitute a health hazard ► A Bacteriological Index for pollution is done to test for coliforms ► Presence of E. coli may mean fecal contamination ► Based on the NSDW, the maximum permissible level for coliforms is not more than 1 for treated water & not more than 3 for untreated water

Radiological Characteristics ► Determination

of radioactive contaminants is not generally done unless there is a very strong reason to suspect their presence ► Presence of Radium 225, Iodine 141 and Strontium 90 would mean nuclear plant discharges reaching the water supply

Water Supply Sanitation ►

► 3. 4. 5. 6.

Objective : To promote and provide safe and potable water through water quality control and surveillance of existing water supply sources Activities Inspection of water supply sources Collection of water samples Disinfection of water sources Household container disinfection

Approved Types of Water Supply Facilities

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   

Level I Facility ( Point Source ) A protected well or developed spring with an outlet but w/o a distribution system Adaptable for rural areas Serves 15-25 households Located not more than 250 m. from the farthest user Yield discharge is from 40 – 140 L/min

2. Level II facility ( Communal faucet system Standposts )  Composed of a source, reservoir , piped distribution network & communal faucets  Located not more than 25 m. from the farthest house  Designed to deliver 40-80 L of water/ day with 1 faucet / 4-6 households  Suitable for rural & urban areas where houses are clustered densely

Level III ( Waterworks System or Individual House Connection)  System with a source, reservoir, piped distribution network & household taps  Suitable for densely populated urban areas  Requires minimum treatment or disinfection 1.

► Unapproved

type of Water facility Water coming from doubtful sources such as open dug wells, unimproved spring , wells that need priming, etc

Treatment of Public Water Supply ► The

nature of treatment depends upon the bacteriological quality of water ► Criteria: Less than 50 coliforms / 100 ml of water - requires disinfection/ chlorination alone 50 – 5,000 coliforms – standard complete treatment 5,000 – 50,000 coliforms – double treatment More than 50,000 – look for another source

Standard Water Treatment ► ► 3. 4. 5. 6.

Usually employed in water treatment plants It involves the following processes Coagulation and flocculation Sedimentation Rapid sand filtration Chlorination

Coagulation & Flocculation ► Process

of changing soluble constituents of raw water to nonsoluble ones by addition of aluminum sulfate or alum to form ‘flocs’ ► A chemical coagulant causes the particles to bind together to form larger , fluffy clusters (flocs) that can be removed by settling or filtering

Sedimentation ► Removal

of solids from water by gravity

settling ► Involves allowing the ‘flocs’ to settle at the bottom of the sedimentation tanks or basins ► At the end of the settling basin , Hydrated lime or Ca(OH)2 is added to the water to increase its ph ► After ph adjustment, Chlorine is added for disinfection & to keep aquatic growths from becoming established in the the filters in the next process

Rapid Sand Filtration ► Process

by which the settled water is filtered thru sand & gravel and drained into the filtered water reservoir ► 1st layer of the filter media is an 18 in. layer of anthracite coal ► 2nd layer - 12 in. of filtered sand ► Four 3 in. layers of stone ranging in size from 1/8 to 3/4 in. ► Bottom – porous layer of glazed tile that supports the filter media

Chlorination ► Most

important single method w/c is universally applied since Chlorine is a powerful germicide , readily available, easy to apply and cheap ► Most important process that is used to produce safe & sanitary drinking water ► 15% solution of Sodium hypochlorite is used

► 2.

3. 4.

5.

Chlorination is important to improve several treatment processes Hypochlorite is sometimes added to raw water ( Pre-chlorination ) to oxidize undesirable materials like Iron & Manganese Hypochlorite is used to improve coagulation Reduces the amount of taste, odor & color producing materials in the water thru oxidation & retardation of decomposition in the settling basins When added prior to filtration, it minimizes biological growth in the filters

► Post-Chlorination

– addition of hypochlorite as a final treatment process and is primarily for the purpose of disinfection ► Enough Chlorine is added to the finished water so that a minimum amount of chlorine remains in the water after a sufficient contact time ► A Free Residual Chlorine of 0.2 – 0.50 ppm should be maintained until the water reaches the consumer at the farthest point in the distribution system

Optional Steps Depending on the Quality of the Raw Water Stabilization – protective measure which reduces the problem of corrosion in the water lines by adding Calciquest , a corrosion inhibitor, to the finished water 2. Fluoridation - safe, effective & economical process to reduce tooth decay  After final addition of hypochlorite, fluoride and corrosion inhibitor, the water is pumped into the distribution system 

Optional Steps Aeration - allows direct contact with oxygen to remove excess chloride & obnoxious odor or taste. Also encourages precipitation of Fe. 4. Softening - Lime filters are used to remove Calcium & magnesium salts 

Agencies Responsible for Disinfection ► Level

I public - Barangay officials and Local Health Agency ► Level II and III - Water supplier ( MWSS, LWUA or water district ► Private wells - Individual / owner

Household Methods of Water Treatment 1. 2. 3. 4. 5. 6.

Boiling Sedimentation Flocculation & Sedimentation Aeration Filtration Chemical Disinfection

Chemical Disinfection

1. Chlorination  properly chlorinated water has residual free chlorine w/c resists recontamination  How to gauge strength of Chlorine: a. Orthotolidine – special organic indicator w/c gives a yellow color in the presence of chlorine b. A faint odor of chlorine after a contact time of 30 min. indicates approx. 0.1 mg/L of water

Chemical Disinfection ► 



Emergency Chlorination of drinking water to make 10% stock solution, add 40 mg of Calcium hypochlorite (2 ½ tbsp. Of bleaching powder) to 1 liter of water 2 tsp. of stock solution to 1 liter of water

2. Disinfection by use of Tincture of Iodine  2 drops of 2% tincture of iodine added to 1 liter of water

Certificate of Potability of Drinking Water ► No

public water system shall be allowed to operate without a certificate of potability issued by the DOH ► The certificate is issued only after the required examinations are performed & the quality of water from the system meets the requirements of the Phil. National Standards for Drinking Water

► The

Types of Water Examination

following examinations are required for drinking water 1. Initial examination – physical, chemical & bacteriological examinations of water from newly constructed systems. Examination of the water for radioactive contaminations should also be done 2. Periodic examination – bacteriological exam should be done as often as possible. Physicochemical examination shall be conducted every

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2.

3.

4.

Water Code of the Philippines

To protect drinking water from contamination, the following measures shall be observed: Washing clothes or bathing w/in a radius of 25 meters from any well or other sources of water is prohibited No artesians, deep or shallow shall be constructed within 25 m. from any source of pollution No radioactive sources or materials shall be stored within a radius of 25 m. from any well or any source of drinking water unless the radioactive source is adequately and safely enclosed in proper shielding

Water Code 1.

2.

No person charged with the management of a public water supply system shall permit any physical connection between its distribution system & that of any other water supply, unless the latter is regularly examined as to its quality by those in charge of the public supply to which the connection is made and found to be potable The installation of a booster pump to boost water direct from the water distribution line of a water supply system where low water pressure prevails is prohibited

Water Code ► 2.

3.

Water Peddlers and Haulers Any person, firm or company engaged in water hauling and vending of water for human consumption shall secure a sanitary permit from the city or municipal health officer Water peddlers & haulers shall undergo medical examination to obtain a health certificate from the local health officer which shall be renewed every year

1.

2.

3.

Water peddlers & haulers are required to obtain water from sources with valid certificate of potability Water containers shall be made of plastic or thin materials to facilitate easy cleaning. The containers shall be cleaned & disinfected before they are filled with water & shall be provided with tight fitting covers All water peddlers & haulers shall observe personal hygiene especially washing of hands with soap & water before working and after using the toilet

Monitoring The Local Health Authority shall establish a Water Surveillance Program thru the creation of Local Drinking Water Quality Monitoring Committee ► Functions of the Committee are: 3. Regular collection & analysis of water samples 4. Evaluate laboratory results as to their compliance standards ►

► 2.

3. 4. 5.

Functions of the Committee cont. Conduct regular or immediate sanitary survey during the existence of a potential cause of contamination Institute remedial measures to correct the deficiency of the water system Inform the public of the latest quality of the drinking water in the locality Perform other functions related to water quality assurance

5 Golden Rules for Safe Water 1. 2. 3.

4. 5.

No one should defecate or urinate near or in a source of drinking water Keep animals away from water collection areas Water for drinking must always be boiled or chlorinated & covered against dust & flies Keep drinking water in a clean container Always wash hands with water & soap before preparing food , eating or feeding little children & after

Summary ► 2. 3. 4. 5. 6.

We have discussed the ff: The situation regarding accessibility to safe water supply Goal and National objectives for water sanitation Sources of water Characteristics of water Approved types of water supply

Summary cont. 1. 2. 3. 4.

Processes involved in standard water treatment Household methods of water treatment Measures to protect our drinking water sources Monitoring to ensure a safe water supply system