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Golder Associates: Draft Report On Environmental Assessment
INTRODUCTION
1.1 Purpose
1.2 Project Overview
1.3 Proponent Identification
1.4 Phase 1 Landfill
1.5 Project Rationale
1.6 Sources of Waste
1.7 Boundaries
1.8 Impact Assessment Approach.
2.0 BASELINE CONDITIONS
2.1 Site Location
2.2 Earthquake Design Criteria
2.3 Climate
2.4 Existing Landfill
2.5 Hydrogeology
2.5.1 Geological Setting and Groundwater Flow Regime
2.5.2 Leachate Control from Phase 1 Landfill
2.5.3 Groundwater Chemistry
2.6 Dust Deposition
3.0 PROJECT DESCRIPTION
3.1 Landfill Siting
3.1.1 Property Boundary
3.1.2 Other Facilities
3.1.3 Airports
3.1.4 Surface Water
3.1.5 Floodplain
3.1.6 Unstable Areas
3.1.7 Other Excluded Areas
3.2 Conceptual Model of Existing Site
3.3 Regulatory Criteria and Existing Water Quality
3.4 Ash Properties
3.4.1 Ash Solids
3.4.2 Ash Leachate
3.5 Conceptual Water Balance Model
3.6 Rationale for Landfill Design Concept
3.7 Engineering Concept
3.8 Capacity and Lifespan
3.9 Conceptual Operations Plan
3.10 Conceptual Closure Plan
3.11 Cost Estimate
4.0 POTENTIAL IMPACTS
4.1 Groundwater
4.1.1 Calculation of Groundwater-to-Leachate Volume Mixing Ratio
4.1.2 Impact of Mixing Ratio on Groundwater Quality
4.2 Dustfall
4.3 Conclusions
5.0 CONFORMANCE TABLE
6.0 CLOSING COMMENTS
1.1 Purpose
1.2 Project Overview
1.3 Proponent Identification
1.4 Phase 1 Landfill
1.5 Project Rationale
1.6 Sources of Waste
1.7 Boundaries
1.8 Impact Assessment Approach.
2.0 BASELINE CONDITIONS
2.1 Site Location
2.2 Earthquake Design Criteria
2.3 Climate
2.4 Existing Landfill
2.5 Hydrogeology
2.5.1 Geological Setting and Groundwater Flow Regime
2.5.2 Leachate Control from Phase 1 Landfill
2.5.3 Groundwater Chemistry
2.6 Dust Deposition
3.0 PROJECT DESCRIPTION
3.1 Landfill Siting
3.1.1 Property Boundary
3.1.2 Other Facilities
3.1.3 Airports
3.1.4 Surface Water
3.1.5 Floodplain
3.1.6 Unstable Areas
3.1.7 Other Excluded Areas
3.2 Conceptual Model of Existing Site
3.3 Regulatory Criteria and Existing Water Quality
3.4 Ash Properties
3.4.1 Ash Solids
3.4.2 Ash Leachate
3.5 Conceptual Water Balance Model
3.6 Rationale for Landfill Design Concept
3.7 Engineering Concept
3.8 Capacity and Lifespan
3.9 Conceptual Operations Plan
3.10 Conceptual Closure Plan
3.11 Cost Estimate
4.0 POTENTIAL IMPACTS
4.1 Groundwater
4.1.1 Calculation of Groundwater-to-Leachate Volume Mixing Ratio
4.1.2 Impact of Mixing Ratio on Groundwater Quality
4.2 Dustfall
4.3 Conclusions
5.0 CONFORMANCE TABLE
6.0 CLOSING COMMENTS
Golder Associates Ltd.
500 - 4260 Still Creek Drive Bumaby. British Columbia V5C 6C6 Telephone 604-296-420D Fax 6CK-293-5253
DRAFT REPORT ON ENVIRONMENTAL ASSESSMENT
WILDWOOD LANDFILL EXPANSION
CATALYST PAPER CORPORATION
WILDWOOD, BC
Submitted to:
Catalyst Paper Corporation
Powell River Division
6270 Yew Street
Powell River. BC
V8A 4K1
EXECUTIVE SUMMARY
The following briefly summarizes the Environmental Assessment for the Phase 2 expansion of the existing Wildwood Landfill. Powell River. BC (Project). Please read the entire report, including appendices, for complete information.
The Project
The Project consists of the vertical expansion (Phase 2) of the closed Wildwood Landfill (Phase 1) at Powell River, and includes installation of a liner, construction of a leachate collection and leak detection system, leachate conveyance piping to an existing leachate line, and storm water drainage. The Phase 2 expansion is anticipated to have a waste disposal capacity of approximately 520.000 m . Assuming that the mini-landfill will reach its capacity in 2008. and based on annual waste disposal rates of 14.000 (anticipated near-term disposal rate) to 25.000 m (based on the operation of the power boiler at 100% capacity) per year, the Phase 2 expansion is anticipated to have a life of approximately 20 to 37 years, with ail estimated closure date between 2028 and 2045.
Purpose
The Phase 2 expansion is for the disposal of paper mill waste and waste from a pulp mill that ceased operation in 2001, including fly ash. asbestos and miscellaneous mill waste.
Baseline Conditions
The Phase 2 expansion will be located on land owned by Catalyst and will be bounded by granitic bedrock on the southwest boundary. The Phase 2 landfill is approximately 200 m to the southeast of Highway 101. and is approximately 300 m to the northwest of Powell Lake. The Phase 2 landfill is located in an area that has a coastal rainforest climate, with a mean annual precipitation of about 1.100 mm.
Soil Conditions - The surficial geology of the site generally consists of compact to dense sands and gravels containing layers of clay, silt and fine sand overlying granitic bedrock. The thickness of the clay, silt and fine sand layers varies from 0.1 m to 1.5 m. and the bedrock surface slopes in a southeast direction at about 4 degrees to Powell Lake. A granitic bedrock knob exists to the west of the Phase 1 landfill.
Groundwater - The groundwater conditions at the site comprise a number of perched aquifers in the sand and gravel layer, overlying a regional groundwater flow regime in the upper, fractured zone of the bedrock and the sand and gravel unit. The perched aquifers have been identified above the confining silt and clay layers at depths of approximately 11 m. 19 m. 29 m and 38 m below existing ground surface, and are recharged by precipitation. Groundwater in the perched aquifers moves laterally within the aquifers and vertically through the confining layers. Groundwater flows in the regional regime in a southeast direction at a velocity on the order of 1 m per day towards Powell Lake, and discharges at springs located on the slope above Powell Lake.
Environmental Protection Measures
Many environmental protection features are included in the Project description. The Phase 2 landfill will be constructed with a geomembrane liner, and a leachate collection and leak detection system. After construction but before commencement of filling with waste, an electrical leak location survey will be conducted on the geomembrane liner and any leaks identified will be repaired. The conceptual operations plan describes the landfill operational measures for the protection of the environment. The conceptual closure plan describes the manner in which the Phase 2 landfill will be closed. Both the operations and closure plans contain provisions for monitoring.
Impact Assessment
The Phase 2 landfill is a structure that is designed to protect the environment. The results of the environmental assessment indicate that the Project will have a low magnitude effect on groundwater and dust deposition.
1.0 INTRODUCTION
1.1 Purpose
This document, which has been prepared by Golder Associates Ltd. (Golder), is part of an application for a permit under the British Columbia Environmental Assessment Act to expand the existing Wildwood Landfill owned by Catalyst Paper Corporation (Catalyst). This report has been prepared in accordance with the Terms of Reference (TOR) issued on September 8. 2006 to the Ministry of Environment (MOE). The TOR were prepared following the MOE's guidance on Applications for Permits under the Environmental Management Act - Technical Assessment.
This application only pertains to the Phase 2 landfill expansion (the Project), which is a vertical expansion of a landfill operated under Permit PR-04565 originally issued on December 7. 1976. This report does not address the Phase 1 landfil except as it directly pertains to development of the Phase 2 landfill.
1.2 Project Overview
The Project consists of the Phase 2 expansion, leachate conveyance piping to an existing leachate line, and storm water drainage.
In this report:
- "Phase 1 landfill'* refers to the existing Wildwood Landfill, including the asphalt-covered area and the mini-landfill:
- "Mini-landfill" refers to the 2-hectare lined area that is currently being filled with waste at the north comer of the Phase 1 landfill:
- "Phase 2 landfill" or "Landfill" refers to the proposed vertical expansion of the Phase 1 landfill: and
- Powell Lake refers to Powell Lake and Powell River.
1.3 Proponent Identification
The proponent is Catalyst Paper Corporation, and the primary Project contact is:
Sarah Barkowski
Manager. Environment & Quality Systems
Catalyst Paper. Powell River Division
6270 Yew Street
Powell River. BC
V8A 4K1
Tel: 604-483-2850
1.4 Phase 1 Landfill
The Phase 1 landfill (previously referred to as the Wildwood Landfill) was owned and operated by MacMillan Bloedel (MB) Paper Ltd. from the 1960's until its closure in 1995. In June 199S. MB Paper Ltd. sold the pulp and paper mill located in Powell River. BC to Pacifica Papers Inc. Pacifica Papers Inc. merged with Norske Skos Canada on August 27, 2001. forming a new company. NorskeCanada. In October 2005. NorskeCanada changed its name to Catalyst Paper Corporation. The Phase 1 landfill has been included in all of these corporate transactions.
While active, the Phase 1 landfill received a variety of waste materials from the Powell River mill site. At the time of its closure in 1995. approximately 70% of the wastes received by the Phase 1 landfill were ash. cinders and clinker from burnt hog fuel, together with small, unburnt wood chips and sand grit. Another 20% of the waste stream was reportedly liquor dregs, and the remaining 10% comprised building debris, timber, wood chips, steel rebar. concrete and steel drums. Black liquor sludge containing organic and caustic liquids was also reportedly landfilled on an infrequent basis. At the time of closure, the southeastern portion of the Phase 1 landfill contained sand and gravel containing Bunker C oil and cutting oil. An asbestos pit was located at the southwestern comer of the property. Landfilling appears to have occurred progressively from the southeast end of the site towards the northwest. There is some uncertainty about the nature of materials contained within the older portion of the landfill
(Hardy BBT Ltd.. 1990).
The waste in the Phase 1 landfill was estimated by MB Paper Ltd.'s staff to range in thickness from S m to 11 m. with the maximum thickness at the south end of the site, except in the vicinity of the Bunker C remediation area, where up to 15 m of waste was estimated (HBT AGRA Ltd., 1994). In many areas of the Phase 1 landfill, excavation prior to placement of the waste was reportedly conducted to the top of a silt layer or material reported to be glacial till.
Closure of the Phase 1 landfill consisted of covering the landfill with a low-permeability asphalt cap to minimize recharge from precipitation, and installation of a leachate collection system. The leachate collection system initially consisted of three recovery wells located within the uppermost perched groundwater flow system (PW95-1. PW95-8 and PW95-9) along the south edge of the Phase 1 landfill. Three additional recovery wells (PW99-2. PW99-4 and PW99-5) were installed in lower groundwater flow zones along the east edge of the Phase 1 landfill in 1999 (and became operational in March 2000) to intercept leachate that may have been by-passing the original collection system. The liquid recovered by these wells is conveyed by pipeline to Catalyst's mill site wastewater treatment plant, where it is treated along with the mill's wastewater prior to discharge.
In January 1996. a new, smaller landfill (referred to as the "mini-landfill") was established within the footprint (northeast corner) of the Phase 1 landfill. The mini-landfill is lined with a geomembrane and soil bentonite liner, and has provisions for leachate detection and collection. Filling of the new mini-landfill cell commenced on August 27. 1996. The mini-landfill is permitted under the Environmental Management Act (Permit PR-04565) to receive fly ash. miscellaneous mill waste and waste asbestos.
1.5 Project Rationale
The Phase 2 landfill is required to provide capacity for the disposal of paper mill waste (primarily ash), as defined by the permit, in the future. The Landfill may also be used to dispose allowable waste associated with a pulp mill that ceased operation in late November 2001. The Landfill is situated on land owned by Catalyst.
1.6 Sources of Waste
Waste disposed at the Landfill will consist primarily of ash from Power Boiler 19 (a fluidized bed boiler) and minor amounts of miscellaneous mill waste, including dregs from the closed pulp mill and asbestos.
Catalyst estimates that approximately 13.000 to 14.000 m3 of fly ash and 500 m3 of miscellaneous mill waste would be disposed of annually in the Landfill over the next few years. Should the power boiler operation be increased to 100% capacity in a few years to increase "green energy" generation and reduce purchased electricity costs, the total volume of waste that could be deposited annually at the landfill could increase to approximately 25.000 m per year.
1.7 Boundaries
The study area for this impact assessment varied for different disciplines as follows:
| Discipline | Description of Spatial Boundary |
| Hydrogeology | Area within and immediately downgradient of the Phase 2 landfill to Powell Lake |
| Dust | Area within 50 m of the Landfill |
The temporal boundaries assume construction commencing in 2008. a landfilling period ranging from 20 years to 37 years, and 25 years after closure (i.e.. post-closure). The baseline was assumed to be the conditions observed during field studies conducted between August 2006 and December 2006.
1.8 Impact Assessment Approach
The TOR identified two potential environmental issues that need to be addressed for this Project:
- Potential impacts by leachate on groundwater; and
- Dustfall generation by the operation of the Landfill.
The Landfill is an environmental protection structure (i.e.. a structure with the purpose of protecting the environment) and thus, environmental protection measures are incorporated as part of the project description. For example, surface water will be protected by providing suitable engineering works to prevent leachate from entering surface water. In the context of this report, "impact" refers to environmental changes that result from the Project, assuming the Project description is implemented. In general, impacts have been predicted according to three criteria (magnitude, geographic extent and duration) defined as follows:
TABLE 1: Impact Classification Definitions
| Criteria | Value | Description |
| Magnitude | High | Substantially above baseline and above standards |
| Moderate | Distinctly above baseline and above standards | |
| Low | Slightly above baseline - no detrimental effect | |
| No Effect | No change from baseline - no detrimental effect | |
| Geographic Extent | Broad | Impact extends beyond study area |
| Moderate | Impact extends beyond the Landfill property but within the study area | |
| Local | Impact is restricted to the Landfill property | |
| Duration | Long-term | Impact extends beyond post-closure phase |
| Moderate-term | Impact extends up to 25 years after Landfill closure | |
| Short-term | Impact is limited to less than 3 years |
Where impact magnitude is "no effect", geographic extent and duration characteristics are not applicable (N. A).
To further clarify the assessment of potential impacts to groundwater, the following definitions for magnitude of impact to groundwater were used:
- High magnitude impact is a predicted annual average leachate percolation rate from the Landfill (based on Hydrologic Evaluation of Landfill Performance (HELP) water balance modelling) to the groundwater being significantly greater than (on a comparable unit area basis) the current annual average precipitation infiltration through the asphalt cover of the Phase 1 landfill. "Significant"' is defined as an increase that is predicted to result in a distinct increase in constituent concentrations and exceedence of many water quality standards in groundwater at and beyond the Landfill property line;
- Moderate magnitude impact is a predicted annual average leachate percolation rate from the Landfill to the groundwater being somewhat greater than the current annual average precipitation infiltration through the asphalt cover of the Phase 1 landfill. "Somewhat"* is defined as an increase that is predicted to result in an increase in the concentration of chemical constituents in groundwater to about the water quality standards at the Landfill property line;
- Low magnitude impact is a predicted annual average leachate percolation rate from the Landfill to the groundwater being slightly greater than the current annual average precipitation infiltration through the asphalt cover of the Phase 1 landfill. "Slightly" is defined as a predicted increase that is unlikely to result in concentrations of chemical constituents in groundwater that exceed the water quality standards at the Landfill property line; and
- Negligible magnitude impact is a predicted annual average leac late percolation rate from the Landfill equal to or less than the current annual average precipitation infiltration through the asphalt cover of the Phase 1 landfill.
Where impact magnitude is "negligible", geographic extent and duration characteristics are not applicable (N/A).
2.0 BASELINE CONDITIONS
2.1 Site Location
The Landfill is located in the Wildwood area of the City of Powell River (see Figure 1). The limits of the Phase 2 expansion, defined using NAD S3 Universal Transverse Mercator (UTM) grid in metres, are as follows:
| Boundary | Easting | Northing |
| North | 388.154 | 5.526.966 |
| South | 388.202 | 5.526.638 |
| East | 388.278 | 5.526.767 |
| West | 387,942 | 5.526.S20 |
The ceutroid of the Landfill will be located approximately at:
- Latitude 49° 53' 0" and longitude 124° 33' 26"
- UTM NAD 83 coordinates: 388.126E 5.526.817N
The legal description of the land within which the Phase 1 and Phase 2 landfills are located (the Landfill property) is:
- Block 48. DL 1901A, Plan 9096. Group 1. New Westminster District.
Catalyst intends to submit a re-zoning application for the triangular-shaped section of land located on the northwest side of the site (part of Block 55. Plan S096) that has been historically used as a landfill.
2.2 Earthquake Design Criteria
The Landfill is located in a relatively high seismic risk area. According to the 2005 National Building Code of Canada, the peak firm-ground acceleration at the site for the Phase 2 landfill is approximately 0.299 g (one g represents a seismic acceleration of 9.81 m/s"). This is referred to as the "design earthquake" that was used in this environmental assessment to assess the seismic behaviour of the Phase 2 landfill. The methodology for the seismic assessment and the results of the analysis are presented in Appendix III of this report
2.3 Climate
According to Environment Canada climate normals, the mean annual temperature in the City of Powell River is 10.6°C. and monthly temperatures range from approximately 4°C in winter to IS.3°C in summer. The total annual precipitation is 1.103 mm. of which about 69% falls between October and March. The wettest month is November and the driest month is July. Snowfall is limited due to relatively mild temperatures and accounts for less than 3% of the annual precipitation.
Recent wind data from the City of Powell River Airport (2001 - 2005) show predominant winds from the east-southeast, with a high frequency from the west-northwest as well. A summary of wind speed and direction is provided in Figure 2 as a windrose.
Click on image to enlarge:
FIGURE 2: Powell River Airport Windrose (2001 - 2005)
2.4 Existing Landfill
The Phase 1 landfill was closed and provided with a 4.S-hectare asphalt cap on the top surface in 1996. To close the Phase 1 landfill, native sand (with some gravel) was placed generally to 0.3 m to 0.5 m thickness (thicker in some areas) to grade the site. The southern half of the graded surface was used as a stockpile area for material to be used in the construction of the mini-landfill. After completion of the mini-landfill construction, the top of the existing landfill was paved with asphalt. Based on the average of six cores of the asphalt obtained by Golder on October 12, 2006. the following properties of the asphalt were determined:
Thickness: 72 mm
Hydraulic conductivity: 4 x 10-10 cm sec
Asphalt content: 6.9%
Relative compaction: 98.3% of maximum theoretical relative density
Air voids ratio: 1.7%
Settlement monitoring of the asphalt surface at three locations by Emery and Rae Land Surveying Ltd. since October 1995 has recorded approximately 30 mm of settlement over the five-year period to January 2001. and no measurable settlement over the six-year period between January 2001 and January 2007. Localized cracking of the asphalt surface was noted in 2000 in one area located at the south edge adjacent to the dewatering pump control shed. The cracks were later filled with an asphalt patching compound. Since 2000. the asphalt surface has been inspected annually and any identified cracks were repaired.
The mini-landfill was designed by Agra Earth and Environmental Ltd. (Agra) in 1996 (project no. VE-50514) and covers an area of approximately 2.0 hectares. The base of the mini-landfill is some 7 to 10 m below the elevation of the adjacent asphalt cap of the closed landfill. Based on Agra's design drawings, the lining system design consists of (from top to bottom):
- Minimum 300 mm of soil cover having less than 5% passing the USS No. 200 sieve:
- Geotextile (a synthetic cloth that can be used as a filter or separator):
- 150 mm of leachate collection system gravel (i.e., sand and gravel having less than 5% passing the USS No. 200 sieve), or geonet on 3 horizontal to 1 vertical (3H:1V) side slopes. In the lowest part, two 200 mm diameter pipes covered with drain rock exist. These pipes daylight at the edge of the east side of the mini-landfill:
- 60 mil ( .5 nun) thick high density polyethylene (HDPE) geomembrane:
150 mm of leachate co
- 500 mm of soil-bentonite;
- Geotextile;
- 150 mm of leak detection system gravel (i.e.. sand and gravel having less than 5% passing the USS No. 200 sieve);
- A leak detection sump located at the southeast end of the mini-landfill and consisting of drain gravel overlying a 200 mm diameter leak detection pipe. This pipe daylights at the edge of the east side of the mini-landfill: and
- Prepared subgrade.
2.5 Hydrogeology
2.5.1 Geological Setting and Groundwater Flow Regime
The following is a general description of the inferred geology and groundwater flow regime at the site.
The Phase 1 landfill is located in a bedrock valley filled with sand and gravel deposits. Prior to filling, the Phase 1 landfill site was a former sand and gravel quarry. The area occupied by the Phase 1 landfill is bounded to the west and east by ridges of granitic bedrock, with exposed bedrock along the southwest edge of the Phase 1 landfill. The ground surface slopes downward (at about 4 degrees) in a southeast direction from the southeast edge of the Phase 1 landfill to Powell Lake. The portion of the hillside immediately above Powell Lake is a steep bank with a slope on the order of 30 degrees. The northwest edge of the Phase 1 landfill appears to represent a saddle point in the surface topography, with the ground surface sloping downwards towards the west and southwest at some distance northwest of the Phase 1 landfill. The topography of the site is shown on Figure 3. and an orthophoto of the site taken on September 5. 2006 is shown on Figure 4.
Beneath the site, the bedrock surface slopes in a southeast direction from an elevation of approximately 100 m above sea level at the south edge of the Phase 1 landfill to an elevation of about 60 m above sea level just before the break in slope above the shoreline.
A medium sand to sand and gravel layer is present above the bedrock surface. Regional groundwater flow occurs in a southeast direction within the upper, fractured zone of the bedrock and the sand unit. The thickness of the saturated zone above the bedrock is inferred to range between 5 m and 10 m in the central portion of the Phase 1 landfill to between 2 m and 20 m downgradient of the Phase 1 landfill. Groundwater flow within the regional zone is estimated to occur under an average gradient of 0.011. resulting in a velocity of on the order of 1 ni day. Groundwater is inferred to discharge from the upper portion of the regional aquifer to springs located on the slope above Powell Lake. Groundwater within bedrock is inferred to discharge as underflow to Powell Lake.
The regional aquifer is overlain by a sequence of sands and gravels that contain layers of clay, silt and fine sand ranging from 0.1 m to 1.5 m in thickness. The presence of these confining layers has created perched groundwater conditions. Perched aquifers have been identified beneath the southern crest of the Phase 1 landfill above the confining layers at depths of approximately 11 m. 19 m. 29 m and 38 m below ground surface. Groundwater is inferred to move laterally in the aquifers and vertically through the confining layers, as illustrated in the geological cross-sections in Figures 5 and 6 and the groundwater contour map of the regional flow zone in Figure 7. Groundwater is inferred to discharge from the regional zone to springs identified on the slope above Powell River. Groundwater discharge may also occur from the shallower perched zones through colluvium on the slope above the spring zone.
As part of this environmental assessment for the Phase 2 landfill, monitoring wells were installed at two locations upgradient of the mini-landfill to augment information on previously established groundwater flow directions and velocities and to confirm that groundwater flow is not directed away from the Phase 1 landfill towards the northwest. The monitoring wells were installed at the north comer of the site (MW06-1L) and to the northwest of previously existing well 93-2 (MW06-2U and MW06-2L) (see Figure 3 for the approximate locations of monitoring wells). Installation of the two new upgradient monitoring wells confirmed that this area is upgradient of the Phase 1 landfill and groundwater flow is directed towards the southeast. While only the regional flow zone was encountered at MW06-1L. both the regional flow zone and a perched, upper flow zone (inferred to represent the 19 m flow zone) were encountered at MW06-2U and L.
2.5.2 Leachate Control from Phase 1 Landfill
The current leachate recovery system for the Phase 1 landfill consists of one operational recovery well (PW95-1) that extracts groundwater from the 11 m flow zone, two recovery wells (PW99-2 and PW99-4) that extract groundwater from the 19 m flow zone, and one recovery well (PW99-5) that extracts groundwater from the 29 m flow zone. Recovery wells PW95-S and PW95-9. which are completed in the 11 m flow zone, have remained dry since May 2000. and are therefore no longer active. Recovery wells PW95-1. PW95-S and PW95-9 were initially activated on September 30. 1995. while recovery wells PW99-2. PW99-4 and PW99-5 were first activated on March 30. 2000. The approximate locations of the recovery wells are shown on Figure 3.
2.5.3 Groundwater Chemistry
Groundwater quality has been monitored downgradient of the Phase 1 landfill since 1989. During the initial stages of monitoring in the 1990"s. groundwater impacted by leachate was characterized by pH values of up to 12.1 and specific conductivities of up to 16.700 uS/cm. These constituents are largely attributed to the leaching of alkaline materials (lime, dregs, ash) that were placed historically in the Phase 1 landfill. Other leachate indicator parameters were detected historically at the following maximum concentrations: sulphate (2.890 mg/L), alkalinity (>6.000 nig L). total organic carbon (TOC) (6*8.325 mg/L), metals, total chlorinated phenols (0.122 mg/L), and dioxins and furans (26,706 pg/L1).
Concentrations of these constituents in groundwater have historically been the highest at shallow depths (in the perched 11 m, 19 m and 29 m flow zones) and in close proximity to the downgradient edge of the Phase 1 landfill. In particular, concentrations were the highest at monitoring well 89-5 located on the east side of the downgradient edge of the Phase 1 landfill and screened in the 11 m flow zone, and at monitoring well AH6L screened in the 29 m flow zone and located approximately 60 m downgradient of 89-5. Concentrations of leachate indicator parameters generally tend to decrease with depth and with increasing distance along the flow path away from the Phase 1 landfill. Historically, elevated levels of these parameters have also been measured in springs discharging to Powell Lake. The following maximum" concentrations were observed in the Spring (SI) before Phase 1 landfill closure and leachate control measures were implemented in the mid 1990's: pH (8.4), specific conductivity (1060 uS/cm), sulphate (69.3 mg/L), alkalinity (242 mg.'L). TOC (42 mg/L). total chlorinated phenols (0.00042 mg/L), and dioxins and furans (4.1 pg L). The approximate location of Spring SI is shown on Figure 7.
Since 2000. the majority of the leachate indicator parameters appear to have stabilized within each of the flow zones, with the exception of TOC and sulphate concentrations at all locations which have been erratic but appear to be declining. Specifically, the elevated concentrations observed to be discharging downgradient of the site into Powell River at the Spring (SI) prior to Phase 1 landfill closure have declined. The December 2006 concentrations of selected leachate indicator parameters measured at SI included pH (8.1). specific conductivity (243 uS cm), sulphate (20.8 mg/1). alkalinity (83.8 mg L). TOC (4.41 mg/L), total chlorinated phenols (not detected) and dioxins and furans (0 pg L). The results from the December 2006 groundwater sampling event are presented in Tables II-C-1 to 5 (referred to as Annex C).
2 Neglects elevated concentrations from the July 2004 sampling event that were considered to be anomalous.
| Constituent | Maximum Concentration in Leachate | Concentration at Spring (SI) prior to Leachate Control Measures | Concentration at Spring (SI) in December 2006 |
| PH | 12.1 | 8.4 | S.l |
|
Specific Conductivity (uS cm) | 16.700 | 1.060 | 243 |
| Sulphate (ma. L) | 2.390 | 69.3 | 20.3 |
| Alkalinity (ma/L) | >6.000 | 242 | 83.S |
| TOC (ms.L) | 6S.325 | 42 | 4.41 |
| Total Chlorinated Phenols (mg.'L) | 0.122 | 0.00042 | Not detected |
| Dioxins and Furans (P2L): | 26,706 | 4.1 | Not detected |
2.6 Dust Deposition
Four dustfall and four metal collection canisters were placed on the north perimeter of the Phase 1 landfill as indicated on Figure 3 to assess dust deposition due to current landfill operations. One field blank (CPP05) was left sealed to be used as a other sample results.
The canisters were exposed from August 1 5, 2006 to August 21, 2006. at which time the canisters were capped to avoid contamination from a typical borehole drilling occurring at the landfill. The canister lids were removed once drilling ceased on September 7. 2006 and sampling was continued until October 3. 2006. This resulted in a total of 30-day exposure for each canister. Catalyst's records indicate that 5 to 6 loads of fly ash shiny were deposited at the mini-landfill per day during the dust sampling period.
Following collection, samples were sent to Maxxam Analytics Ltd. for analysis of total dustfall. fixed (inorganic) dustfall and metals. Total dustfall represents the total mass of dustfall collected in the sample. Fixed dustfall is the mass of the inorganic component of the sample. The metal analysis measures the deposition rates of selected metals in the sample. The results of the dustfall sampling indicated that three of the four total dustfall and fixed dustfall values were below the detection limit of the gravimetric analysis (0.5 and 0.3 mg 100cm2 30days. respectively). The other dustfall sample was obtained from Station CPP03 located 70 m southeast from the north corner of the Phase 1 landfill (adjacent to the landfill access road). The total dustfall deposition rate in the sample at this location was 9.75 mg 100cm2 30days (see Appendix I for results), and is well below the British Columbia pollution control objective for residential areas of 52.5 mg/ 100cm2 30days. Analysis of trace metals in the samples indicated that most metal species were below or very near detection limits. However, all but one sample had detectable phosphorus and all samples had detectable silicon. Both of these elements occur naturally and the overall deposition rates are very low. One sample had detectable uranium and zirconium, but the values were just above the method detection limits.
3.0 PROJECT DESCRIPTION
3.1 Landfill Siting
The following summarizes criteria for landfill siting (based on the BC Landfill Criteria for Municipal Solid Waste since there are no similar criteria available for industrial landfills), and describes conceptually how the Landfill addresses these criteria. Figure S shows the Landfill and surrounding lands.
3.1.1 Property Boundary
Criteria - The Landfill Criteria state that a 50 m wide buffer zone is required between discharged municipal solid waste and the property line. However, buffer zones between 15 m and 50 m may be approved depending on adjacent land use and environmental factors.
Landfill Site - The actual buffer between the nearest property not owned by Catalyst and the proposed waste is more than 50 m. This nearest property is occupied by Highway 101.
3.1.2 Other Facilities
Criteria - The Landfill Criteria state that the distance between discharged municipal solid waste and the nearest residence, water supply well, water supply intake, hotel, restaurant, food processing facility, school, church, or public park is to be a minimum of 300 m. However, lesser setbacks may be approved where justified.
Landfill Site - The Phase 1 landfill is located at least 300 m from the nearest water supply intake, hotel, restaurant, food processing facility, school, church, or public park. There are no water supply wells located downgradient between the landfill and Powell Lake.
There are several residences and a gas station and convenience store located between 100 m and 300 m from the Landfill. However, the impact assessment (see Section 4) predicts that the impact to these residences and the store from dust, and the impact on their groundwater from Landfill leachate are considered to be low.
3.1.3 Airports
Criteria - The Landfill Criteria state that the distance between an airport utilized by commercial aircraft and a landfill containing food wastes that may attract birds is to be a minimum of 8 km.
Landfill Site - The Landfill will not contain food wastes and therefore, the Landfill site meets this criterion. The Landfill is also located more than 6 km from Powell River Airport.
3.1.4 Surface Water
Criteria - The Landfill Criteria state that the distance between discharged municipal solid waste and the nearest surface water is to be a minimum of 100 m. However, lesser setbacks may be approved where justified by hydrogeological investigations.
Landfill Site - The Landfill is located more than 300 m from Powell Lake, which is the nearest significant perennial surface water body to the Landfill. Therefore, the Landfill site meets this criterion.
3.1.4 Surface Water
Criteria - The Landfill Criteria state that the distance between discharged municipal solid waste and the nearest surface water is to be a minimum of 100 m. However, lesser setbacks may be approved where justified by hydrogeological investigations.
Landfill Site - The Landfill is located more than 300 m from Powell Lake, which is the nearest significant perennial surface water body to the Landfill. Therefore, the Landfill site meets this criterion.
3.1.5 Floodplain
Criteria - The Landfill Criteria state that landfills sited within 200-year floodplain* need to be designed to prevent washouts.
Landfill Site - The Landfill is not located within a floodplain since the overall topography slopes towards the ocean and the natural ground surface in the area of the Landfill ranges between elevation 120 m and 135 m (Geodetic datum).
3.1.6 Unstable Areas
Criteria - The Landfill Criteria state that the landfill is not to be located in an area that is unstable due to static forces, such as due to improper filling on poor foundation soils, landslide areas, and Karst terrain.
Landfill Site - A geotechnical site investigation conducted at the site indicates that the natural, undisturbed foundation soils beneath and at the toe of the Phase 1 landfill are considered to be stable with respect to static forces and the design earthquake (see Appendix III).
3.1.7 Other Excluded Areas
Criteria - The Landfill Criteria state that the landfill is not to be located within the boundaries of those areas (e.g.. parks or designated wildlife areas) listed in Section 3(e) of the Special Waste Regulation.
Landfill Site - The Landfill is not identified on available maps as being located within an area that has been listed in Section 3(e) of the Hazardous Waste Regulation (which superseded the Special Waste Regulation in 2004).
3.2 Conceptual Model of Existing Site
The following is a generalized and simplified description of the existing. pre-Project site conditions based on the baseline investigations described in Section 2. This conceptual model provides context for the proposed environmental protection features for the Phase 2 landfill.
The site is located in an area that has a coastal rainforest climate, with a mean annual precipitation of about 1.100 mm year.
The Phase 1 landfill comprises two areas:
- A 2-hectare mini-landfill that is lined with a HDPE geomembrane and soil-bentonite composite liner, and is currently an active landfill for the mill: and
- A 4.8-hectare area that is closed and has a final cover consisting of. on average, 72 mm thickness of asphalt.
The Phase 2 landfill will be developed on top of the existing Phase 1 landfill and the outer limits of the waste of the Phase 2 landfill will be within the footprint of the Phase 1 landfill. Adjacent to the west side of the Phase 1 landfill is an approximately 30 m high bedrock knob with a maximum elevation of 164.2 m and a steep face facing the Landfill. The bedrock knob is approximately 9 m above the highest point of the landfill. Figure 9 shows a typical cross-section of the Phase 2 landfill.
Beneath and around the Phase 1 landfill, the soil conditions are inferred to generally consist of compact to dense sands and gravels containing layers of clay, silt and fine sand overlying granitic bedrock. A granitic bedrock knob exists to the west of the Phase 1 landfill. Surface water near the site consists of ephemeral water courses (including those on the asphalt final cover) that flow during rainfall events. Powell Lake is located about 250 m downslope from the toe of the Phase 1 landfill and more than 300 m from the toe of the Phase 2 landfill.
Groundwater flow", as illustrated by the schematic in Figure 10. consists of a regional groundwater flow zone within the deep sands and gravels and the upper portion of fractured bedrock, together with a complex sequence of shallower groundwater flow zones perched above discontinuous silt layers. Groundwater in the regional flow zone and overlying perched zones is directed towards Powell Lake. The velocity of groundwater flow within the regional flowr zone is estimated to be on the order of 1 m'day. Groundwater is inferred to discharge from the regional zone to springs on the slope above Powell Lake and possibly from some of the shallower perched zones through colluvium on the slope above.
3.3 Regulatory Criteria and Existing Water Quality
Groundwater chemistry was compared to the standards outlined in the BC Contaminated Sites Regulation (CSR) for the protection of freshwater aquatic life and drinking water. The freshwater aquatic life standards are considered applicable because groundwater is ultimately discharged to the freshwater aquatic environment of Powell Lake. Although the closest water wells are estimated to be more than 5 km east (and cross-gradient) of the site, drinking water standards were also applied because Powell Lake serves as a water supply source for the Wildwood community. The water supply intake for Wildwood is over 1.5 km upstream from the site. The water supply intake for the mill site is located downstream of the site. However, this water is not used as drinking water.
A review of the groundwater chemistry results from the 2006 annual monitoring program (Appendix II) indicates that the groundwater chemistry at the property boundary (i.e.. at the spring SI) was below the CSR standards for all parameters for which standards are available. No CSR standards are available for dioxins and fiuans. No dioxin and furan congeners were detected during the wet-season monitoring event at the Spring in December 2006. However, two congeners were detected at pg L levels during the dry-season monitoring event. Since no dioxin and furan congeners with non-zero toxicity factors were detected dining the dry-season monitoring event, the toxicity equivalence (TEQ) for the dry-season monitoring event was 0 pg/L.
3.4 Ash Properties
3.4.1 Ash Solids
Golder tested one cylinder of ash that was cast into a concrete sampling cylinder at the mini-landfill on December 15. 2006. and the following summarizes the test results:
| Parameter | Result | |
| Bulk density | I.eSOkaiir* | |
| Water content | 34% by dry weight | |
| Unconfined compressive strength | 2.1 MPa after 32 days | |
| Hydraulic conductivity | 2x10" cm sec |
Catalyst samples the ash for trace metals, leachable metals, and major components on a regular basis. The following summarizes the average values of parameters in 25 ash samples collected by Catalyst from August 29. 2005 to January 23. 2006.
| Parameter | Average Value | |
| Chloride. Cl- | 2.0% by weight | |
| Sulphate. SO42' | 1.5%by weight | |
| Loss on ignition | 2.6% by weight | |
| 5 mm to 600um size | 0.25% by weight | |
| 600 um - 150 um size | 9.1% by weight | |
| <150 um size | 90.7% by weight | |
| Bulk density | 910 k2m: |
Catalyst estimates that the major constituents of the fly ash are oxides of silicon, calcium and aluminium, which comprise approximately 80% of the ash by weight. The remaining 20% is reported to consist of oxides of numerous trace metals. The ash is not considered to be a hazardous waste as defined by the Hazardous Waste Regulation. In particular:
- TCLP Tests - The results of Toxicity Characteristic Leaching Procedure (TCLP) tests on 25 ash samples collected by Catalyst between August 29. 2005 and January 23, 2006 are summarized in the table below, which indicates that none of the metals were at concentrations that exceed the limits defined by the Hazardous Waste Regulation Leachate Quality Standards;
| Leachate Metals (TCLP) | Maximum (ppm) | Minimum (ppm) | Average (ppm) |
| Leachate Quality Standards (ppm) | |||
| Antimony | ND | |||||||
| Arsenic | ND | 2.5 | ||||||
| Barium | ND | 100 | ||||||
| Beryllium | ND | |||||||
| Boron | 7.00 | 1.35 | 3.95 | 500 | ||||
| Cadmium | 0.05 | 0.05 | 0.05 | 0.5 | ||||
| Calcium | 2.6S0 | 342.0 | 1.756.1 | |||||
| Chromium | 0.29 | 0.29 | 0.29 | 5 | ||||
| Cobalt | 0.07 | 0.06 | 0.06 | |||||
| Copper | XD | 100 | ||||||
| Iron | 2.50 | 0.20 | 0.70 | |||||
| Lead | XD | 5 | ||||||
| Magnesium | 239 | 0.64 | 137.5S | |||||
| Mercury | XD | 0.1 | ||||||
| Nickel | 0.44 | 0.28 | 0.36 | |||||
| Selenium | XD | 1 | ||||||
| Silver | XD | 5 | ||||||
| Thallium | XD | |||||||
| Vanadium | 1.23 | 0.16 | 0.35 | |||||
| Zinc | 2.40 | 2.40 | 2.40 | 500 | ||||
Note: "ND" stands for 'not detectable".
- Dioxins/Furans in Ash - Golder obtained a sample of the ash on December 15. 2006 and had ALS Environmental test the ash solids for dioxin. furans. The ash sample was reported to have a toxicity equivalence of 138 pg/g (NATO or I-TEQJ) or 0.13S ppb. This is far below the lower limit of 100 ppb (ng/g) TEQ that defines a hazardous waste in British Columbia, and even below the 0.35 ppb Standards for Triggering Contaminated Soil Relocation Agreements of the Contaminated Sites Regulation for Soil Relocation to Non-Agricultural Land;
- Dioxins Furans in Synthetic Ash Leachate - Golder obtained a sample of the ash on December 15, 2006. crushed the sample, and had ALS Environmental extract synthetic leachate in accordance with US Environmental Protection Agency (USEPA) Method 1312 using water as the leachant. ALS Environmental then tested the synthetic leachate for dioxin furans. The synthetic leachate was reported to have a toxicity equivalence of 3.6S pgL. This is far below the maximum contaminant level (MCL) for dioxin in water of 30 pg L as set by the USEPA: and
- PAHs - The October 26. 2006 sample was also tested for polycyclic aromatic hydrocarbons (PAHs). Most of the tested PAH compounds had concentrations below detection limits and all concentrations were well below the Standards for Triggering Contaminated Soil Relocation Agreements of the Contaminated Sites Regulation for Soil Relocation to Non-Asricultural Land.
3.4.2 Ash Leachate
To assess leachate impacts, leachate chemistry data from the Ciofton Block 2B landfill were assumed to be representative of leachate from the Phase 2 landfill. The Crofton Block 2B Landfill contains ash from the Crofton mill boiler located in Crofton. BC.
To support the use of Crofton Block 2B leachate for the analysis of the Phase 2 landfill, a synthetic precipitation leachate procedure (SPLP) was conducted on a sample of the mill ash according to USEPA Method 1312. except that the leachant (i.e.. liquid that flowed through the sample) was non-pH adjusted, reagent grade water (since the synthetic leachate was analyzed for more parameters than just metals). The results of this test were compared with the results from a sample of the ash from the Crofton mill earned out using the same methodology. The results, summarized in Table II-E-3. are similar for both samples and support the use of Crofton Block 2B leachate in the analyses for the Phase 2 landfill.
Leachate from the leachate collection system for the Phase 1 landfill is not considered to be representative of leachate from the future Phase 2 landfill because the former may be affected by dilution by groundwater and by wastes that will not be deposited in any significant quantities in the Phase 2 landfill (e.g.. wood chips, dregs).
3 The Contaminated Sites Regulation (Schedule 7) indicates that NATO International Toxicity Equivalency Factors (TEF) are to be used.
3.5 Conceptual Water Balance Model
Water balance modeling was carried out using the Hydrologic Evaluation of Landfill Performance (HELP) model, version 3.07. The model results were used as input to the development of a design concept for the leachate management system for the Phase 2 landfill and for conceptual design of the leachate collection system. Two activity scenarios for a lined landfill with leachate collection system at approximately 15-m pipe spacing were assessed: operational scenario (i.e.. period during which the Landfill is active) and post-closure scenario (i.e.. period after closure when the Landfill is no longer being filled with waste). The waste was assumed to have a hydraulic conductivity of 1 x 10" cm sec. which is two orders of magnitude higher than that determined by a test on a cylinder of ash as described in section 3.4.1.
The Landfill was assumed to have a single HDPE geomembrane liner installed on a prepared sand fill base having a hydraulic conductivity of 1 x 10-2 cm/sec. and with a suitable quality assurance quality control program but allowing for the potential for one 1-cm2 hole per hectare.
For the operational scenario, it was assumed that surface runoff would occur from a 0.5% active Landfill slope. For the post-closure scenario, the hydraulic conductivity of the drainage layer above the waste was assumed to be 1 x 10-2 cm sec. Surface slopes of 3 % and 33% were modeled, and the drain spacing in the final cover drainage layer was assumed to be 10 m. Figure 11 shows conceptually the final cover cross-section analyzed.
The results of the HELP modeling for the post-closure scenario are shown conceptually on Figure 12 and indicate the following leachate percolation rates through the geomembrane liner to the sand bedding below the Phase 2 landfill:
- Operational scenario: 1.2 mm year
- Post-closure scenario: 2.6 mm year
If the asphalt layer cracks and is not impermeable, the above are the estimated leachate percolation rates into the Phase 1 waste. If the existing asphalt layer remains impermeable, then leachate percolation into the Phase 1 waste would be about 0.1 mm year for both scenarios.
The above leachate percolation rates are very small and are not expected to significantly influence groundwater flow.
3.6 Rationale for Landfill Design Concept
The asphalt cover of the Phase 1 landfill has low permeability and is presently an effective barrier to the infiltration of precipitation into the existing waste. Asphalt is widely known in the pavement industry as a "flexible pavement" because it can deflect or flex under many cycles of loading while maintaining its integrity. As such, it is anticipated that the existing asphalt would deform, while largely maintaining its integrity, in response to settlement caused by the existing waste compressing under the load of the additional waste that will be placed in the Phase 2 landfill. The magnitude of settlement cannot be determined accurately due to the heterogeneous nature of the waste. However our experience at woodwaste landfills suggests that short-term (i.e.. one to two years) settlements of 2% to 10% of the thickness of the existing waste may occur. Based on previously observed localized cracking of the asphalt surface, it is our opinion that the existing asphalt cannot be completely relied upon to function as a primary liner for the Phase 2 landfill. Therefore, a flexible membrane liner (geomembrane) will be provided for the Phase 2 landfill.
In the unlikely event that there is a sharp break in the asphalt of up to 50 mm, our analysis indicates that a HDPE geomembrane overlying a minimum 300 mm of sand bedding could survive this condition without yielding.
The water balance analysis indicates that a single HDPE liner on a sand base with a suitable quality assurance quality control program should be able to limit leakage from the Phase 2 landfill to less than an equivalent of 2.6 mm per year after closure of the Landfill. This is about 0.2% of the annual precipitation at the City of Powell River. The groundwater assessment indicates that this would result in an equivalent of less than 1.5% concentration of leachate in the groundwater prior to discharging at the springs on the slope above Powell Lake. This is less than the 3.7% concentration of leachate in groundwater that would result in exceedances of groundwater quality criteria at the discharge point to Powell River.
Based on the above results, a single HDPE liner (or functionally equivalent material) on a prepared sand base with a compatible leachate collection system is considered to be suitable for the protection of groundwater at the site.
As an added safety measure, a leak location survey will be conducted on the HDPE liner to allow repair of leaks after liner installation. This will minimize leakage through the geomembrane liner.
3.7 Engineering Concept
The above section discussed the rationale for the design concept. The following provides further information on the design concept for the major components of the Phase 2 landfill. A plan showing the conceptual bottom of Phase 2 contours is provided on Figure 13.
The Phase 2 landfill will be constructed on top of both the mini-landfill and the existing asphalt-covered Phase 1 landfill, and will occupy a 6.1-hectare area. The Phase 2 extension over the mini-landfill will rely on the existing lining system of the mini-landfill (i.e.. new liner will not be constructed over the mini-landfill for the Phase 2 landfill development).
On top of the existing asphalt area, a layer of sand bedding, overlain by a geomembrane. will be provided. The geomembrane will shingle over the mini- landfill (i.e.. the geomembrane will extend over the edge of the existing geomembrane of the mini-land fill) a minimum of 6 m. The conceptual contours of the geomembrane liner are illustrated on Figure 14. The sand bedding layer will be provided with perforated pipes to allow detection of leachate that leaks past the geomembrane and flows to these pipes.
A drainage layer will be provided above the geomembrane. I is anticipated that the above-liner drainage system would consist of gravel-covered perforated pipes (or equivalent drainage geocomposite) at approximately 15-m spacing, with the gravel wrapped with a geotextile installed in a clean sand drainage layer. The collected leachate would flow to the existing leachate conveyance pipe to the mill. Figure 15 shows a conceptual design of the leachate collection system for Phase 2.
As an additional safety action, an electrical leak location survey of the Phase 2 geomembrane is proposed after geomembrane and drainage layer placement is complete. Geomembrane leaks detected by this survey would be repaired. Thus, after the electrical leak detection survey and repair, the actual number of leaks in the liner is anticipated to be less than one hole per hectare as assumed in the water balance analysis.
Contaminated runoff from the active area of the Landfill will be directed to a new "active pond", and then from the active pond to the existing leachate conveyance pipe. The purpose of the active pond is to provide temporary storage of runoff from the active landfill surface in the event of a large storm that exceeds the capacity of the existing leachate conveyance pipe. The active pond will be lined with a geomembrane. Figure 16 shows the approximate alignment of the existing leachate conveyance pipe, the conceptual location of the active pond, and the conceptual layout of pipelines connecting the active pond and leachate collection system for Phase 2 with the existing leachate line. Uncontaminated runoff (i.e.. surface runoff that does not contact the active area of the Landfill) will be collected by a drainage course along the perimeter of the active area that will drain the runoff to the existing surface water drainage course located to the southeast of the Phase 1 landfill.
3.8 Capacity and Lifespan
Figure 17 provides a conceptual plan for the Phase 2 landfill at closure. This Phase 2 landfill is estimated to have a total airspace capacity of 638.000 m . excluding the airspace remaining in the mini-landfill up to the elevation of the surrounding asphalt. Allowing for a 0.75 m thick final cover and a 0.75 m thick geomembrane liner system, the total waste volume available in the Phase 2 landfill is approximately 520.000 m . The maximum thickness of Phase 2 waste is anticipated to be about 18 m. which is estimated to exert a pressure of approximately 300 kPa on the existing asphalt surface.
Assuming the mini-landfill will be at capacity up to the elevation of the adjacent asphalt in 2008. the Landfill is anticipated to have a life of approximately 20 years (with an estimated closure date of 2028) based on a waste disposal rate of 25.000 m /year to approximately 37 years (with an estimated closure date of 2045) based on a waste disposal rate of 14.000 m year.
The construction phase of the Landfill is projected to be in the summer of 2008. The operational phase is anticipated to be from 2008 to a time between 2028 and 2045 when final closure would occur. The post-closure phase would be beyond Landfill closure between 2028 and 2045.
3.9 Conceptual Operations Plan
The following is a conceptual plan for operating the Landfill:
a) Materials Acceptable for Disposal
Pulp and paper mill waste, including boiler ash. waste asbestos and miscellaneous mill waste.
b) Materials Not Acceptable for Disposal
Domestic-type waste, such as waste from kitchens, eateries, washrooms or offices, shall not be disposed in the Landfill unless approved by the Ministry of Environment.
c) Maximum Waste Disposal Rate
For the purposes of the permit, the maximum waste disposal rate is anticipated to
be 25.000 m3/year. The normal waste disposal rate is anticipated to be approximately 13.000 to 14.000 m3 of fly ash and 500 m3 of miscellaneous mill waste per year. In the event that the power boiler will be operated at
100% capacity in a few years, the waste disposal rate is anticipated to increase to approximately 25.000 m per year.
d) Site Development and Landfilling Method
The Landfill will be filled progressively in a manner that is orderly and maintains stability. The waste will be filled in lifts by constructing an outside berm of ash that has a relatively low slump consistent with the construction of 3 horizontal to 1 vertical (3H:1V) slopes. This outside berm will serve to contain ash loads that have a higher water content and higher slump.
e) Staffing and Equipment
Two special trucks (i.e., concrete mixers) normally transport the ash to the Landfill. The ash is mixed with water such that the ash flows like concrete when it is discharged at the Landfill. Other wastes are transported to the Landfill in trucks suited to the transport of the particular waste. The truck wash water will be discharged to the leachate collection system. It is anticipated that the Landfill will not have a full-time attendant.
f) Leachate Management
Leachate collected by the leachate management system w 11 be discharged by gravity into the existing leachate collection system for the Phase 1 landfill and plumbed into the normal conveyance piping to the mill. During operation of the Landfill, contaminated runoff from the ash surface will be directed into a lined pond (active pond) where it will discharge into the existing leachate collection system. Uncontaminated runoff will be collected by a drainage course along the perimeter of the active area that will drain the runoff to the existing surface water drainage course located to the southeast of the Phase 1 landfill.
Prior to construction of the Phase 2 landfill, the existing leachate conveyance line will be inspected by Catalyst to confirm that its capacity has not diminished with time.
g) Surface Water and Erosion Control
Surface water will be diverted away from the Landfill by a diversion drainage course that will be lined by the existing asphalt cover for the Phase 1 landfill. The approximate location of the diversion drainage course is illustrated on Figure 17. The diversion drainage course will be designed to handle flows with a minimum 20-year return period.
Barren soil surfaces will be protected from erosion by vegetating the exposed soil as soon as possible after works have been completed in the area.
h) Dust Control
If required by the MOE or if Catalyst personnel consider it necessary, a water truck or functionally equivalent method will be used for dust control.
i) Operational Inspections
Catalyst will undertake periodic inspections of the Landfill operations to verify compliance with the permit and operations and closure plan, the condition of the Landfill works, evidence of erosion or excessive dust, excessive ponding or unusual Landfill settlement, and adequacy of safety measures.
j) Access and Traffic
There is an existing fence, with automatic gate, to control entry to the Landfill. Signs indicating that only authorized persons are allowed entry to the Landfill will be posted. Figure 17 shows one access road up to the top of the Landfill: this will be the main access road.
Detailed design may identify that it is necessary to construct a second road to the top of the Landfill. This second road, if required, would be used only when the area around the main access road is being filled (thus preventing vehicles from
using the main access road).
k) Operational Contingencies
Procedures to address the following operational contingencies will be prepared for a detailed Operations Plan:
- Fires;
- Unauthorized dumping;
- Increase of leachate indicator parameters in groundwater monitoring wells;
And
Detection of leachate in surface water.
l) Monitoring
The following provides a conceptual monitoring plan, which will be reviewed annually as part of the annual report.
Groundwater - Groundwater will be monitored at not less than seven selected groundwater monitoring wells. The locations, frequency, analyte list, quality control and quality assurance practices, and other details will be contained in the detailed Operations Plan.
Surface water - There are no permanent water bodies immediately adjacent to the Landfill, and therefore, regular sampling of surface water is not part of the monitoring plan.
m) Annual Report
An annual report will be prepared that includes:
- Review of groundwater quality data;
- Recommendations for changes, if any. to the monitoring plan;
- Recommendations for changes, if any. to the operations plan; and
- Catalyst's estimate of the type and volume of waste placed during the year and an estimate of the remaining lifespan of the Landfill.
3.10 Conceptual Closure Plan
The following is a conceptual plan for closing the Landfill:
a) Estimate of Total Waste Volumes. Tonnage and Life of Landfill
Upon closure, it is estimated that the Landfill will have the volumes as described in Section 3.8. Depending on the annual rate of waste disposal, the estimated closure date of the Landfill is between 2028 and 2045.
b) Contour Plan of Landfill at Closure
A conceptual contour plan of the Landfill at closure is provided on Figure 17. c)
c) Final Cover Design
Figure 11 shows a conceptual cross-section of the proposed final cover. The conceptual Landfill cover design consists of:
- Grass, trees and shrubs;
- 0.15 m of topsoil as a growing medium;
- 0.3 m. or possibly more, of soil having a hydraulic conductivity of less than 1.2 x 10" cm sec before vegetation influence;
- 0.3 m. or possibly more, of soil having a hydraulic conductivity of 1x10"" cm sec or higher. A system of drains will be installed in the final cover;
- Final Landfill slopes between 3% and 35%;: and
- Surface water drainage works that are designed to allow runoff that meets applicable water quality criteria to flow in a controlled manner to the perimeter ditches.
In the first three years after placement of final cover in the first area of the Phase 2 landfill, the discharge water quality from the system of drains in the final cover will be monitored twice annually during rainfall events to confirm its performance and that the water meets discharge standards.
d) End Use of Landfill After Closure
After closure and unless other mill uses are identified, landfill surface will be
covered with trees, shrubs and grass.
e) Monitoring Plan
A monitoring plan will be included in an updated closure plan that will be
prepared prior to closure of the Landfill. The monitoring plan will include provisions for monitoring of groundwater and surface water, as well as monitoring of water quality from drains in the final cover in the first three years after placement of the first final cover materials.
f) Operation of Leachate Management System
The leachate collection system will be maintained during post-closure until an engineering assessment indicates that the system is no longer necessary for the protection of the environment.
g) Operation of Storm Water Diversion System
Works that divert surface water around the landfill will remain after closure.
3.11 Cost Estimate
The total capital cost, excluding engineering, of the Phase 2 landfill is estimated to be approximately $3 million in 2007 dollars, assuming that all costs exclude taxes. construction involves only one mobilization, and no upgrades to the existing leachate conveyance system are required. This cost estimate does not include operations, maintenance, or closure costs.
4.0 POTENTIAL IMPACTS
4.1 Groundwater
In this section, the potential effects of the Phase 2 landfill on groundwater quality are assessed. Since the existing groundwater quality conditions are acceptable to the MOE and represent baseline conditions, the potential hydrogeological impact of the Phase 2 landfill was evaluated by considering possible changes to groundwater chemistry related to the Project. In accordance with the Terms of Reference, the impact to downgradient groundwater is evaluated at locations where groundwater discharges from
the springs above Powell Lake at the property boundary (see Figure 7 for the approximate locations of springs).
The potential impact of the Landfill on groundwater chemistry is related to the composition of the leachate associated with the waste material, the volume of leachate trickling through the liner and entering the groundwater system, and the groundwater flow rate as discussed below.
4.1.1 Calculation of Groundwater-to-Leachate Volume Mixing Ratio
To assess the potential impact to water quality, the groundwater-to-leachate volume mixing ratio was calculated at the spring (SI) located adjacent to Powell Lake. This calculation was completed by mixing the estimated volume of leachate generated from the new landfill with groundwater flowing beneath and downgradient of the Landfill (i.e.. groundwater that flows through the perched flow zones and recharges from precipitation). The analysis was completed on a volumetric basis and did not account for additional chemical reactions that may occur during leachate transport or for additional dilution by advection. dispersion or biodegradation processes. It is expected that these processes would further reduce the predicted leachate concentrations at the spring.
Mixing calculations were completed for a "best estimate"' of hydrogeologic input parameters (presented in Appendix II) and for an upper and lower range of hydraulic conductivity and precipitation recharge values. All assumptions and sources of information for each step are provided in Appendix II.
Leachate generated from the Landfill was modelled as initially mixed with groundwater flowing through the perched flow zones beneath the Landfill. The analysis was completed for a scenario having a leachate percolation rate of 2.6 mm/year (i.e.. post-closure scenario) through the geomembrane liner to the sand below the liner. Following this mixing, the percent leachate in groundwater below the Landfill was estimated to be approximately 2% to 7%.
Based on a comparison of historical pumping rates relative to groundwater flow within the upper perched flow zones, it was estimated that approximately one half of the groundwater from the perched zones is recovered by the collection system. Groundwater that is not captured by the groundwater recovery wells was conservatively assumed to discharge entirely into the springs with some additional dilution from precipitation infiltrating into the perched flow zones. Based on this assessment, the percent leachate in groundwater just prior to discharging at the springs was estimated to be approximately 0.6% to 1.5%.
The percent leachate in groundwater stated above assumes that the existing asphalt will be fully cracked after closure of the Phase 2 landfill and will provide no resistance to leachate percolation into the Phase 1 waste and the underlying native soil. However, it is anticipated that much of the asphalt would likely maintain its integrity under the additional load of the Phase 2 landfill due to its flexibility, and that extensive cracking is unlikely after closure of the Landfill. This would reduce the rate of leachate percolation through the asphalt into the Phase 1 waste, and the actual percent leachate in groundwater after Landfill closure is anticipated to be lower than the estimated value stated above. In addition, the leak detection layer that will be installed under the asphalt would collect some of the leachate leaking through the asphalt and would further reduce the percent leachate in groundwater.
As part of the above predictions, the perched aquifer system was conservatively assumed not to mix with regional aquifer prior to discharging to the springs. In reality, this mixing would likely occur and would further reduce the predicted percent leachate concentrations.
4.1.2 Impact of Mixing Ratio on Groundwater Quality
Groundwater-to-leachate volume mixing ratios were evaluated by comparing the predicted percent of leachate in groundwater discharging at the springs with the minimum amount of Landfill leachate that would result in an exceedance of the lowest applicable regulatory standards, assuming chemically conservative conditions exist downgradient of the Landfill. This assumption is conservative as it assumes few constituents in the leachate are non-reactive (conservative), meaning that they do not undergo chemical, biological or physical attenuation processes along the groundwater flow path, which include adsorption, ion exchange, secondary mineral precipitation, biodegradation and redox reactions.
The minimum amount of leachate from the Landfill that was required to cause an exceedance of applicable standards was calculated using the lower of the freshwater aquatic life (AW) or drinking water (DW) CSR groundwater standards. For this calculation, leachate from a similar landfill at Catalyst's Crofton mill was considered representative of the leachate that would be generated at the Landfill. This leachate was mixed with the groundwater quality results from the Spring (SI) sample collected in December 2006 (Annex C).
The percent leachate required to trigger an exceedance of the most conservative standards calculated for each constituent listed in Annex C was greater than 3.7%, which is more than double the percent leachate predicted at the Spring (0.6% to 1.5%) due to the Project. The only possible exception is chloride, for which there are no existing groundwater concentrations from the Spring. Based on the limited historical chloride data from other locations at the Phase 1 landfill, the chloride concentration at the Spring is anticipated to be less than 100 nig L. A groundwater chloride concentration of 100 mg/L would result in 3.6% leachate being required to trigger an exceedance of the CSR DW standards. However, the DW standard for chloride is to protect against taste and odour concerns, and is not a health concern.
In summary, the predicted percent leachate in groundwater just prior to discharging at the springs (0.6% to 1.5%) is not expected to increase groundwater concentrations above groundwater standards at the Landfill property line. Therefore, the impact of the Project on groundwater quality is considered to be of low magnitude, local extent and long-term.
4.2 Dustfall
The dustfall monitoring at the Phase 1 landfill between August 15 to 21, 2006 and September 7 to October 3, 2006 was carried out during normal landfill operations. The measured dustfall concentrations in all canisters were below criteria and are considered to be low. In addition, based on the Powell River Airport wind data, the prevailing winds are considered to be from the east-southeast and west-northwest.
Thus, dust generated at the site would not. on most occasions, be blown towards the existing residences to the north of the Landfill. The ash waste is brought to the site in a moist condition, and the waste typically binds and hardens with time if not disturbed.
Based on the dustfall monitoring results, the prevailing wind data from Powell River Airport, and the fact that the ash waste is moist when brought to the site and hardens with time, it is Golder*s opinion that the off-site impacts of dustfall due to normal operations at the Landfill will be of low magnitude, local extent and moderate duration. However. other activities in the region, including logging around the Landfill, could increase the transport distance of airborne dust. Additional dust could also be generated due to traffic by waste transportation trucks on the waste. Therefore, the following additional dustfall monitoring is recommended:
- One round in the summer of 2007 during normal operating conditions: and
- One round during dry weather within the first two years of filling of Phase 2 to confirm the predicted dustfall impacts.
If the above monitoring indicates dustfall concentration exceeding the Provincial objectives due to normal landfill operations, dust suppression measures, such as a water truck, could be implemented to control dustfall levels.
4.3 Conclusions
The Phase 2 landfill is to consist of a geomembrane-lined landfill with a leachate collection and leak detection system. An electrical leak location survey of the geomembrane liner will be carried out and identified leaks will be repaired prior to filling the local area with waste. A detailed operations and closure plan will be prepared outlining the manner that the Landfill is to be operated and the monitoring is to be conducted.
Based on the Project description, the results of the environmental assessment indicate that the Project will have a low magnitude effect on groundwater and dust deposition.
5.0 CONFORMANCE TABLE
The following provides a conformance table to enable cross-referencing of the Terms of Reference requirements with the relevant sections of this report.
TABLE 2: Conformance Table
| TOR Section | EA Report Section | |
| 1 1 | Executive Summary | Executive Summary |
| 1 2 | Table of Contents | Table of Contents |
| 1 3 | Introduction | 1.0 |
| 14 | Site Location | 2.1 |
| 1 5 | Source and Characteristics of Waste | 1.6 and 3.4 |
| 1.6 | Baseline Conditions | 2.0 |
| Hydrogeology | 2-5 | |
| Permeability of Asphalt | 2.4 | |
| Dust Deposition | 2-6 | |
| 1.7 | Project Description | 3.0 |
| Landfill Siting | 3.1 | |
| Identification of Potential Environmental Issues | 1.8 | |
| Water Balance Modelling | 3.5 | |
| Rationale for Design Concept | 3>.6 | |
| Engineering Design Concept | 3.7 | |
| Project Phases | 3.8 | |
| Conceptual Operations Plan | 3.9 | |
| Conceptual Closure Plan | 3.10 | |
| Cost Estimate | 3.11 | |
| 1.8 | Potential Impacts | 4.0 |
| Hydrogeology | 4.1 | |
| Dust Deposition | 4.2 | |
| 1.9 | Conclusions | 4.3 |
| 2.0 | Conformance Table | 5.0 |
6.0 CLOSING COMMENTS
Golder Associates Ltd. (Golder) has prepared this report in a manner consistent with that level of care and skill ordinarily exercised by members of the engineering and science professions currently practicing under similar conditions for active industrial landfills in British Columbia, subject to the time limits and physical constraints applicable to this report. No other warranty, expressed or implied, is made.
This report and all plans, data, drawings and other documents, as well as electronic media prepared by Golder are considered its professional work product and shall remain the copyright property of Golder. who only authorizes Catalyst Paper Corporation and Approved Users to make copies of the report. Approved Users are entities that Golder has stated in writing as Approved Users. Electronic media are susceptible to unauthorized modification, deterioration and incompatibility and therefore, electronic media versions of Golder's work product cannot be relied on.
These analyses are subject o several inherent sources of uncertainty that are common to impact assessments and predictive modelling, such as:
- Natural systems are dynamic and influenced by a highly complex interaction of variables. The current level of understanding, by the profession, of the science associated with these variables, and the relationships amona them, is not complete:
- The volumes of soil, bedrock, water and dust sampled and tested are extremely small in relation to the total volume of these materials that exist within the study area. Soil and groundwater conditions between sampling locations may vary from those described in this report. Therefore, predictions of fixture impacts cannot be made with absolute certainty; and
Geological data from borehole drilling and the review of available information were synthesized to assess the overall geology of the site. This information, together with information from the monitoring well installation and water level monitoring, was used to develop a conceptual model of the site hydrogeology, including the delineation of hydrostratigraphic units, and the occurrence and direction of groundwater now. However, because 01 the inherent variability in hydrogeological conditions, both temporally and spatially localized areas of preferential flow that are not described in the above conceptual model may be present.
Nevertheless. Golder is confident in the assigned rankings for the magnitude of predicted changes to the groundwater quality, and for dustfall for the following reasons:
Groundwater flow calculations were completed in this assessment for the range of input parameters considered reasonable for this site based on the data collected to date:
The analysis used a number of conservative assumptions, including: neglecting attenuation that could occur in the unsaturated zone below the Landfill, neglecting dilution that may occur from mixing in the regional aquifer system prior to discharging at the springs, and neglecting leak location and repair that would be carried out on the geomembrane after its installation;
The chemical mixing in the groundwater was conducted using the conservative assumption that constituents' masses will be conservative during mixing. Few are non-reactive (conservative), meaning they do not undergo chemical, biological or physical attenuation processes along the groundwater flow path, which include adsorption, ion exchange, secondary mineral precipitation, biodegradation and redox reactions; and
Dustfall impacts can be readily mitigated (e.g.. by water truck) should any dustfall
concerns develop during operations.
Yours very truly.
GOLDER ASSOCIATES LTD.
Colin L.Y. Wong. P.Eng.
Principal
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