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Decommissioning of Pyramid Mountain Microwave Facility (Authors: Masten Brolsma, P.Eng and Court Sandau, Ph.D., P.Chem.) 1.0

INTRODUCTION

In 2004, Jacques Whitford Limited (Jacques Whitford) was retained to complete an environmental site assessment (ESA) and assist in remediation activities during the decommissioning of the Pyramid Mountain microwave tower facility located just outside Jasper, Alberta. The facility was constructed in 1963 by CN/CP as part of a national telecommunications system. Based on changes in technologies, the current owner of the system decided to decommission the facility. Though visible from the Town of Jasper, logistics and limitations in working with a remote site such as access, altitude and mountain weather needed to be employed during the assessment and remediation of the site. The following provides an overview of the characterization, remediation and screening level risk assessment completed at the site. 2.0

SITE OVERVIEW

The site is located on Pyramid Mountain, approximately 10 km northwest of the Town of Jasper, Alberta, in Jasper National Park. Three areas related to the site required assessment and remediation: SnoCat storage garage near Pyramid Lake, Tram Base area and the Microwave Facility on the summit of Pyramid Mountain. Access to the Base Site is via a gated, 12 km fire road leading from Pyramid Lake to the Tram Base. The Garage site (elev. 4000’ / 1220 m) is located approximately 1 km up the access road. The Garage site is within approximately 250 m of Pyramid Lake and a creek draining Pyramid Lake and was used for storage of a snow coach used for snow clearing of the road and general storage. The Tram Base (elev. 6529’ / 1990 m) was occupied by a tram station and a diesel-fuelled power generation facility. The tramway right-of-way connected the Summit Site to the Base Site via an aerial tram, and was occupied by overhead cables supported by three towers. The self-supported microwave terminal tower and associated single-storey building occupied the Summit Site (elev. 9065’ / 2763 m). A tram line was used to transfer diesel fuel from the base of the mountain to the summit where the microwave tower was located. The original underground storage tanks (USTs) used for diesel storage, were eventually replaced with aboveground storage tanks (ASTs) both at the Base and Summit in 1994. Pyramid Mountain Decommissioning

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REMEDIATION CRITERIA

The site was leased from Parks Canada. Although a remediation criteria was not specified in the lease, the lease did identify that the site must be returned to a state “satisfactory” to Parks Canada. As the site is located within a National Park, Federal guidelines were used to assess the level of contamination, wherever possible. Petroleum hydrocarbons and other contaminants of concern were compared to the following: • • •

Canadian Council of Ministers of the Environment (CCME) Canada Wide Standards (2001) based on eco-soil and/or freshwater aquatic life pathways; CCME Soil Quality Guidelines with Parkland settings; and CCME Freshwater Aquatic Life (FAL) guidelines. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX) are compared to the CCME (2004) Canadian Soil Quality Guidelines for Parkland settings or Freshwater Aquatic Life (FAL) criteria. The adjacent photo shows the area surrounding the Tram Base.

4.0

BACKGROUND INFORMATION

The leasee at Pyramid Mountain has changed numerous times due to changes in corporate ownership. Standard to pre-acquisition due diligence, a Phase I ESA was completed by the new owner. Previous environmental assessment, remediation and environmental screening conducted at the site were documented in the following reports: • • •

•

Pyramid Mountain Microwave Facility Upgrading – Project Description and Environmental Screening Report, report prepared by TERA Environmental Consultants (Alta.) Ltd. (TERA), February, 1994; Pyramid Mountain Microwave Facility – Contamination Cleanup Monitoring Report, report prepared by TERA Environmental Consultants (Alta.) Ltd., September, 1994; Phase I Environmental Site Assessment, Microwave Tower Site, Tramway Terminal Site and Tramway Right of Way, Locator Number 1029, Plan 4839 MC, Lots Y and Z, Pyramid Mountain, Alberta, dated September 26, 2002, prepared by Jacques Whitford Environment Limited; and Environmental Screening Report, Demolition of Facilities, Pyramid Mountain Site (ESR), dated June 15, 2004, prepared by Packbox Consulting.

Pyramid Mountain Decommissioning

4.1.1

Summit

Previous environmental work conducted by TERA in 1994 documented four 10,000 L diesel USTs located outside the Summit microwave building. The USTs were used to store diesel fuel for power generation. These tanks were routinely filled by transporting diesel fuel from the Tram Base via two tanks on the tram car. An area at the Summit was also identified as a used crankcase oil dump area. During remediation work in the summer of 1994, the diesel USTs were removed and replaced with three 9,000 L ASTs, and soils from the oil dump area were removed by helicopter for off-site disposal. PHC concentrations in composite confirmatory soil samples collected from the UST and crankcase oil dump area excavations were within the applicable criteria at that time (Alberta Environment’s February 1991, Draft Subsurface Remediation Guidelines For Underground Storage Tanks). In 1995, subsequent to the remediation work, a letter was issued to the leasee at the time, indicating that all requirements had been met and that Parks Canada considered the remediation at both the Base and Summit sites to be complete. The Phase I ESA conducted by Jacques Whitford in August 2002 identified surface staining from hydrocarbon spillage at the Summit and Site in addition to the potential for hazardous building materials typically associated with buildings constructed in the 1960’s. 4.1.2

Tram Base

Previous environmental work conducted by TERA in 1994 documented that four 15,000 L diesel aboveground storage tanks (ASTs) and one 10,000 L diesel underground storage tank (UST) were located outside the base site building. The ASTs and UST were used to store fuel for power generation and tram operation. In addition, two 1,200 L tanks were attached to the tram car and used to transport diesel fuel from the Base Site to the Summit Site. Propane to heat the building was stored in ASTs outside the compound fence. TERA conducted remediation work in the summer of 1994, during which the diesel ASTs and UST were removed and replaced with one 25,000 L diesel AST. The remediation work also included the excavation and removal of petroleum hydrocarbon (PHC) impacted soil. PHC concentrations in composite confirmatory soil samples collected from the excavation following the soil removal were within the applicable criteria at that time (Alberta Environment’s February 1991, Draft Subsurface Remediation Guidelines For Underground Storage Tanks).

Pyramid Mountain Decommissioning

The Phase I ESA conducted by Jacques Whitford in August 2002 identified surface staining from hydrocarbon spillage at the Tram Base in addition to the potential for hazardous building materials typically associated with buildings constructed in the 1960s. 4.1.3

Garage

Other than identifying the potential environmental concerns associated with the storage of petroleum hydrocarbons and maintenance of the SnoCat, no Phase II activities had been conducted at the garage. 5.0

DECOMMISSIONING ASSESSMENTS AND REMEDIATION

Following the requirements of the Canadian Environmental Assessment Act (CEAA) related to decommissioning of facilities within a National Park, the June 2004 Environmental Screening Report (Packbox, 2004) recommended that a Phase II ESA be conducted at the Summit, Tram Base and Garage sites. A summary of the Phase II ESAs completed by Jacques Whitford and the subsequent remediation activities at these areas is summarized below. 5.1

Summit

5.1.1

Assessment Activities

An assessment of the diesel fuel aboveground storage tank (AST) area and surface staining under the tramway was completed on August 31, 2004. Using a hand auger, trowel or mini-excavator, a total of 15 testpits were excavated to investigate potential petroleum hydrocarbon impacts as shown on Drawing No. 1. Field screening and selection of representative soil samples for laboratory analysis was completed using a photoionization detector (PID). Soil samples were analyzed for the following parameters: benzene, toluene, ethylbenzene and xylenes (BTEX), metals, polycyclic aromatic hydrocarbons (PAHs) and F1, F2, F3 and F4 petroleum hydrocarbons (PHC). For landfill permitting purposes, samples were also analyzed for flash point, leachable metals and pH.

Pyramid Mountain Decommissioning

Surface Staining

Drawing No. 1: Summit Site Plan With the exceptions of the samples from testpits TP4 and TP8, concentrations of xylenes, F1, F2 and/or F3 petroleum hydrocarbons in excess of the applicable guidelines were identified in the AST area to a minimum depth of 1.3 m below grade. Sample TP11 was collected within an interstitial space between the floor slab and the building footing. Spillage from inside the generator room likely resulted in some petroleum hydrocarbon impact within the 75 mm (~ 3” ) wide space. Elevated concentrations of F2 and F3 petroleum hydrocarbons in excess of the applicable guidelines have been identified. Impacts are likely associated with waste oil and/or diesel fuel. The sample was also analyzed for metals and PAHs. No metals, with the exception of zinc, were found in concentrations exceeding the applicable guideline. The sample from TP11 also had a naphthalene concentrations (0.67 mg/kg) marginally exceeding the applicable CCME guideline of 0.6 mg/kg. Two surficial samples (TP14 and TP15) were collected on the slope below the tramway. Surface staining is present over an approximate area of 6 m x 5 m. There is relatively little granular material mixed amongst the boulders in this area. Concentrations of F3 Pyramid Mountain Decommissioning

and F4 petroleum hydrocarbons in excess of the applicable guidelines have been identified in the area and were likely associated with waste oil spillage. The TP15 sample was also analyzed for metals and PAHs. No metals, with the exception of barium, were found in concentrations exceeding the applicable guideline. The sample from TP15 did not have any PAH concentrations exceeding the applicable CCME guideline. 5.1.2

Surface Staining

Remedial Action Plan

Copies of the summit assessment results and a proposed remedial action plan (RAP) were presented to Parks Canada by Jacques Whitford. The proposed remediation for the Summit Site included the following: •

AST Area: Excavation of diesel-impacted granular backfill above the bedrock. Accessible soils with petroleum hydrocarbon concentrations exceeding the applicable CCME guideline to be excavated and transferred outside Jasper National Park to a provincially-approved Class II landfill. Jacques Whitford personnel to be present to screen soils and determine the extent of the excavation and collect confirmatory soil samples for laboratory analysis. The excavation area to be backfilled and sloped to meet the remaining floor slab with concrete from the tram tower demolition and/or clean granular material from another portion of the summit area. Summit Building Floor Slab: Access to any impacted soils under the floor slab would require demolition and removal of the 300 mm thick slab. Given that Parks Canada intended to use this slab at a future date, any impacted soils in this area would be effectively capped by both the slab and building footing which extends to approximately 0.6 m (2 feet) below grade. Hence, no additional soils were intended to be removed from underneath the slab. Should indications of residual impacts be observed along the footing, then a hydrocarbon resistant liner (i.e., 25 mil ORP) would be installed at the base of the footing (see Drawing No. 2). To prevent snow melt and/or rainfall from entering into the interstitial space, a strip of 25 mil thick hydrocarbon resistant liner will be placed near the top and covered with clean gravel. The 3” insulation located between the slab and footing should have helped reduce migration of hydrocarbons from inside the building to under the slab. A 6 mil poly was also placed under the slab during construction which should also help reduce vertical migration. The 3” insulation was not to be removed as part of demolition activities.

Pyramid Mountain Decommissioning

Drawing No. 2: Summit AST Remedial Excavation Cross-section Below Tram Line: Surficial petroleum hydrocarbon impacted soils below the tramline are mixed with boulders and on a steep slope. Removal on impacted soils would be difficult and as such it was proposed that approximately 0.3 m of native cover be placed over this area. To demonstrate the low risk in leaving these soils in place under additional surface cover, an environmental screening of possible valuable ecosystem receptors (VECs) was completed as part of the remedial action plan. It was expected that only the “ecosoil contact” pathway would be applicable. As stated above, additional soil analyses are being completed for the TP15 sample for polycyclic aromatic hydrocarbons (PAHs) to assess if any volatile and/or carcinogen parameters are still present in these likely weathered hydrocarbons. Results of the screening level ecological risk assessment would be provided to Parks Canada. The proposed RAP was accepted Parks Canada on September 14, 2004. 5.1.3

Screening Level Risk Assessment

Following the remedial excavation for the diesel AST area, residual soil impacts in excess of the applicable remediation guidelines were still present at the bottom of the former tank nest and under a floor slab that remains in place. An environmental liner was installed in the AST area and then backfilled with clean materials. No remedial excavation of the waste oil impacted soil on the steep slope below the summit was proposed. Rather, the placement of approximately 300 mm of native surface cover was

Pyramid Mountain Decommissioning

planned for June 2005. A screening level risk assessment (SLRA) was complete as part of the agreed upon remedial action plan for the Summit site. In 1996, the CCME adopted the use of a three-tiered risk assessment framework composed of sequentially more sophisticated and complex evaluation. The three tiers, or levels, of this approach consist of a screening assessment, preliminary quantitative risk assessment and a detailed quantitative risk assessment. These tiers represent increasing levels of effort; however, whatever level of effort, the risk assessment should address the same essential components, those being hazard assessment, receptor characterisation, exposure Exposure Receptor assessment and risk characterisation. The Pathway RISK qualitative SLRA presented in this report is equivalent to the first level CCME screening level assessment. Hazard The objective of the qualitative SLRA was to identify significant source-pathway-receptor linkages and to provide a qualitative assessment of risk to human and ecological receptors based on potential hazard. If all three of these conditions – exposure, receptor, hazard – are met, then a potential risk to either human or ecological health may exist.

The following steps were undertaken in the qualitative SLRA: • • •

• • • • •

Contaminant Screening - Identification of the chemicals that may pose a health risk in the soil, groundwater, surface water and sediment by comparing them to screening criteria; Hazard Assessment – Identification of the potential toxicity or hazard that each of the chemicals may pose to human or ecological health; Receptor Screening – Determination of the receptors that may be exposed to the hazard(s) identified above in the soil, groundwater and surface water at the site. In the case of ecological receptors, the species, communities, habitats and valued environmental components (VECs) should be identified; Exposure Pathway Screening - Qualitative evaluation of the likelihood, or degree, to which the receptors will be exposed to the identified hazard(s) in the various media; Development of Conceptual Model – Illustration of the relationship between the chemicals of concern, the receptors, and the exposure pathways (as depicted in the figure above); Risk Characterization - Qualitative assessment of the potential health risk of each hazard to each receptors, based on the degree of exposure; Risk Management Recommendations – Based on the results of the SLRA, recommendations in order to limit any potentially unacceptable risks; and Uncertainty Assessment - A qualitative assessment of the uncertainty associated with the risk estimation. Pyramid Mountain Decommissioning

The primary objective of the SLRA process is to screen for potential risks associated with identified areas and chemicals of potential concern (CoPCs). Based on the results of the SLRA for the subject site, if any potential risks are identified, those CoPCs may be further investigated and a site-specific quantitative risk assessment may be conducted. The CoPCs carried forward in the SLRA were barium, zinc, naphthalene, and petroleum hydrocarbon (PHC) Fractions F1 (C6 – C10), F2 (>C10 – C16), F3 (>C16 – C32) and F4 (>C32) in surface soil as shown in Table 1. For the purpose of the SLRA it was assumed that CoPC impacts exist beneath the Site, at concentrations similar to the maximum measured concentrations. Table 1 – Summary of CoPCs in Soil – Parkland Land Use Chemicals of Potential Concern Metal Metal PAH Petroleum Hydrocarbons Petroleum Hydrocarbons Petroleum Hydrocarbons Petroleum Hydrocarbons

Barium Zinc Naphthalene F1 (C6 – C10) F2 (>C10 - C16) F3 (>C16 – C32) F4 (>C32)

CCME (2003) SQG1 – Residential/ Parkland (ppm) 500 200 0.67

CCME (2001) CWS For Coarse-grained Surface Soils2 Residential/ Parkland (ppm) nv nv nv

370 (West Wall)

nv

130

4800 (West Wall)

nv

450

23000 (TP11-1)

nv

400

12000 (TP14, TP15)

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2800

Maximum Soil Concentration (ppm) 632 (TP15-1) 350 (TP11-1) 0.67 (TP11-1)

Notes: nv – no value 1 - Canadian Council of Ministers of the Environment (CCME) Canadian Environmental Quality Guidelines: Soil Quality Guidelines (1991, Updated 1997, 1999 & 2003) 2 - Canadian Council of Ministers of the Environment "Canada-Wide Standards for Petroleum Hydrocarbons (PHC) in Soil" (May 2001) for coarse grained surface soils (< 1.5 m below grade) – Eco Soil Contact (plants and invertebrates)

Based on the site assessment activities undertaken at the subject site to date and a review of the data provided by those site assessment activities, the SLRA determined that residual barium, zinc, naphthalene, and PHC fraction F1, F2, F3 and F4 concentrations at the site pose a low risk to human and ecological (hoary marmot, pika and mountain goat) receptors. Using the conservative assumptions included in the SLRA, no potential adverse health effects associated with the exposure of human or ecological receptors to the maximum concentrations of CoPC measured to date at the Summit area of the site were found.

Pyramid Mountain Decommissioning

5.1.4

Remedial Activities

The summit remedial excavation was completed between September 6 to 10, 2004. Approximately 80 m3 (160.12 tonnes) were excavated and placed in soil bags for transfer from the summit to the tram base and then to a Class II landfill. All granular backfill from the tank nest was found to be impacted with diesel fuel. The soil was excavated and placed in soil bags for transfer off the summit. The excavation was extended to approximately 2.0 to 2.4 m deep where either the concrete anchor slab from the original UST nest or bedrock was found. The excavation was extended horizontally to the building footing on the western side or the edge of the mountain slope on the other sides. Boulders on the perimeter of the excavation were a limiting factor in the size of the excavation. Jacques Whitford personnel were on site to direct the excavation and collect confirmatory soil samples. Confirmatory soil samples for laboratory analyses were collected from the base and sidewalls of the final excavation. Residual F1, F2 and/or F3 petroleum hydrocarbon concentrations on the base and sidewalls were found to exceed the applicable guidelines. No residual BTEX concentrations were found exceeding the applicable guideline.

Pyramid Mountain Decommissioning

5.1.5

Restoration

A site inspection of the final excavation was completed by Parks Canada in September 2004. Parks Canada was in agreement that all soils reasonably accessible for excavation had been removed. Jacques Whitford provided Parks Canada with details on the liner installation to manage the residual impacts. On October 5, 2004, Jacques Whitford personnel were on site to assist in the installation of the environmental liner and supervise the start of backfilling. Backfilling the excavation continued from October 6 to 15, 2004 prior to the work being halted by winter weather and was completed in June 2005. The 3” insulation gap between the remaining floor slab and footing were also be sealed in June 2005.

Former surface stained area

5.2

Tram Base

5.2.1

Assessment Activities

The screening level risk assessment completed for the Summit Site (AST nest and slope below the tram) showed that there are no unacceptable ecological or human risks from the residual impacts at the Summit Site. Placement of clean surface cover over the surficially stained area below the summit tram was completed in June 2005.

On August 31, 2004, eight hand auger holes were used to complete an initial assessment of the surface staining under the tram loading area. Concentrations of F1, F2 and F3 petroleum hydrocarbons in excess of the applicable guidelines were identified in the tramway area.

Pyramid Mountain Decommissioning

The sample from below the tram loading area was also analyzed for leachable metals, pH and flash point for landfill disposal permitting purposes. No leachable metals were found in detectable concentrations and meet the requirements of the Alberta Waste Control Regulation. A flashpoint of > 61°C was found which defines it as a non-hazardous material under the Transportation of Dangerous Goods Act. On October 15, 2004, a preliminary remedial excavation and delineation program was completed using a trackedhoe excavator. Demolition of the tram building was not complete at the time and the diesel AST was yet to be removed. These conditions and other remaining construction equipment restricted the available investigation areas. The preliminary remedial excavation extended from the tram loading platform southerly towards the lease limit. The excavation was approximately 10 m (north – south) x 6 m (east – west). A similar methodology to the Summit excavation was followed in terms of field screening with a PID and collection of confirmatory soil samples from the base and sidewalls of the excavation. Based on visual impacts below the former platform footings, a testpit was excavated to approximately 4.5 m below grade, the maximum reach of the excavator. Soils deeper than 4 m below grade were wet and continued to exhibit hydrocarbon staining. A soil sample collected from the base had a F2 PHC concentration of 1000 mg/kg that exceeds the applicable F2 guideline of 450 mg/kg. Two testpits (TP1 and TP2) were excavated to the east and north of the excavation for delineation purposes. No field indications of petroleum hydrocarbon impact were found. Prior to demolition of the tram building, observations of hydrocarbon odours were noted in the crawl space. Demolition of the area was incomplete in October 2004 and as such further investigation and an estimate of any impacted soils, if any, can not be completed until it is completed. Similarly, an investigation of possible impacts under the diesel AST was completed in June 2005.

Pyramid Mountain Decommissioning

5.2.2

Remediation

Diesel impacted soils with petroleum hydrocarbon concentrations exceeding the applicable CCME guideline that were excavated on October 16, 2004 were returned to the excavation as truck access to the site was no longer possible due to snow. The remainder of the site demolition and remedial excavation was scheduled for June 2005. From June – December 2005, soils with petroleum hydrocarbon concentrations exceeding the remediation objectives were excavated and transferred outside Jasper National Park to Class II landfills. The excavation area will be backfilled and/or regraded to meet the final grade for the area. Jacques Whitford personnel was present to screen soils to determine the extent of the excavation and collect confirmatory soil samples for laboratory analysis. 5.3

Garage

Jacques Whitford personnel were on-site on August 31, 2004 to complete an assessment of the garages. A visual inspection inside the SnoCat garage and the two testpits on the back (east side) were excavated to assess potential petroleum hydrocarbon impacts. The second garage was not inspected but reportedly did not contain any materials of environmental concern. A soil sample of oil-stained gravels was also collected after the SnoCat had been removed. Detectable concentrations of F2 and F3 petroleum hydrocarbons below the applicable guidelines were identified in the sample. No leachable metals were found in detectable concentrations and meet the requirements of the Alberta Waste Control Regulation. A flashpoint of > 61°C was found which defines it as a non-hazardous material under the Transportation of Dangerous Goods Act. The garages were removed from the site in October 2004 thus allowing access to any hydrocarbon-impacted soils. Jacques Whitford completed landfill permitting for the analytical the West Yellowhead Regional Landfill and acceptance of the material was granted. Waste oil and/or diesel impacted soils (i.e., surfaced stained soils) with petroleum hydrocarbon concentrations exceeding the applicable CCME guideline were to Pyramid Mountain Decommissioning

be excavated and transferred outside Jasper National Park to the Hinton landfill. Jacques Whitford personnel will be present to screen soils to determine the extent of the excavation and collect confirmatory soil samples for laboratory analysis. The excavation area will be backfilled or recontoured to meet the final grade for the area. A report will be provided to Parks Canada documenting the work completed. The remedial excavation (surface scrape) was scheduled for June 2005. 6.0

LOGISTICS

A brief summary of the logistics associated the assessment and remediation of the Pyramid Microwave facility are: • • •

• •

Mountain Weather (Rain, Snow, Freezing Temperatures, Flying From Summit after Tram Removal). Short Constructions season (June – early October). Access: The 12 km fire road from Pyramid Lake to the Tram Base gains approximately 2500 vertical feet (approx. 10% grade on last 4 km). Excavation Water Discharge (Freshwater Aquatic Life concerns). Ecological Setting (National Park).

Authors Masten Brolsma, P.Eng., is a Senior Environmental Engineer with Jacques Whitford. He has 15 years experience in the assessment, remedial options evaluation, risk assessments, remediation, permitting and reporting for the residential, military, commercial and industrial sites in Western Canada and the Arctic including sites within National Parks. Courtney D. Sandau, Ph.D., PChem., is a Senior Risk Assessor and serves as Jacques Whitford’s Western Regional Lead for the Risk Assessment Service line. Court’s expertise is the toxicology of contaminants and their effects on human and wildlife health. He has project related experience with human health and ecological risk assessments and community based risk assessments from across Canada. Court has also developed litigation experience working with attorneys as an expert witness for class action law suits and board appearances. Pyramid Mountain Decommissioning