Technical Volume 10 is an evaluation of the potential impacts of the proposed construction of the South Fraser Perimeter Road on the groundwater quantity and quality conditions.
This Volume shows that the SFPR will impact the Bog by being as close as 50 m to the inferred mound, running through the lagg zone along many of the sections and interfering with the conductivity of the acrotelm layer.
It is also acknowledged that highway run-off water would have a significantly negative affect on the quality of the groundwater in the Bog, but the proponent does not say what mitigation measures would be put in place to capture and prevent highway run-off from changing the water chemistry of the Bog.
These impacts are not only of great concern to the public and are reiterated in documentation from the Burn’s Bog Society, Delta Council and the Scientific Advisory Panel. For many years these agencies have voiced concerns about people walking in the Bog because of the potential for damage to the delicate Microsystems by foot traffic, so how could a 4 lane highway be built in such close proximity to the Bog without substantial negative impacts?
The construction of a major roadway along the northern and western edges of the Bog would mean serious detrimental impacts that would threaten the life of the Bog, and would be contrary to the principles of the protective covenant that is in place to protect the Bog. Therefore the current plans for the SFPR in this area should be dismissed and alternative routes that avoid the north and west sides of the Bog should be sought.
Reference locations in the document and the applied reasoning that resulted in this review summary are listed below.
| Location of Quote or Reference |
Relevant & Specific Quote and/or Comment |
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| Page i para 4 |
Archaeological deposits (i.e., Midden Deposits) were encountered at locations F and G. |
| Page ii para 1 |
The SFPR is aligned over three aquifers mapped and classified by the MOE. The relatively deep and highly productive Newton Upland Aquifer is located east of 128th Street and has low vulnerability to surface contamination. Two aquifers located west of 128th Street are relatively shallow and unconfined, with a correspondingly high vulnerability to surface contamination. These include the South Fraser River Junction Aquifer between 112th and 128th Streets, and the South Fraser River Delta Aquifer, which underlies the entire SFPR west of 112th Street. |
| Page ii para 2 |
Water levels measured at locations A, B, C, D, E, M, N, P and Q confirm the presence of a relatively shallow water table with gentle gradients, flowing radially from Burns Bog.There is a possibility that a reversal in groundwater flow directions towards the bog may occur at one or more locations during dry-season conditions. |
| Page ii para 2 |
Continuous water-level monitoring will be conducted in the vicinity of Burns Bog over the 2006 year to assess the potential for seasonal variations in groundwater flow directions. |
| Page iii para 1 |
Additional groundwater quality sampling will be conducted during the 2006 year to determine the lateral extent of the water types during dry season conditions. |
| Page iv para 1 |
The potential impacts to groundwater hydraulics during both the construction and operation phases will be primarily related to the construction techniques and materials utilized along the SFPR route. |
| Page iv para 3 |
The potential impact of construction on watercourses crossing the alignment is medium, |
| Page iv para 4 |
While occurrences are likely a rarity, the impact of a potential hydrocarbon spill in the event of a major vehicle accident could be high; therefore, a spill response plan should be in place to address this possibility. |
| Page iv para 5 |
The potential for the SFPR to impact well water levels, or the hydraulics of the aquifers hosting the wells, is considered low. Similarly, the impact of SFPR construction and operation on groundwater quality in drilled water wells with adequate surface seals is expected to be low. However, there is a medium to high potential for migration of surface water runoff, particularly during the construction phase, along the casings of dug wells and drilled wells that are improperly sealed and located in close proximity to the alignment. |
| Page iv para 5 |
Consideration should be given to collecting water samples from active water wells that are dug, and drilled water wells located in close proximity (within 50 m) of the alignment to establish baseline water quality conditions prior to construction. |
| Page v para 1 |
Hebda et al. (2000) reported that the physical extent of the Burns Bog water mound is the primary influence on the overall viability of Burns Bog. While the majority of the SFPR is located outside of the Bog mound, five sections (designated Areas 1 to 5 in Figure 14) have been identified where the proposed roadway is positioned nearest to the approximate extent of the Bog mound defined in Figure 6.6 of Hebda et al. (2000). Based on the extent of the water mound inferred from the field program, the proposed roadway fill footprint might extend partly over the mound boundary and, therefore, onto potentially functional Bog east of Area 1 and in Area 2. In Area 3, the proposed SFPR is potentially aligned within 50 m of the inferred mound boundary, while in Area 5, the proposed SFPR is potentially aligned within 200 m of the inferred mound boundary. |
| Page v para 2 |
In areas located in close proximity to the inferred Bog mound, preferential groundwater flow from Burns Bog into roadway fill associated with the SFPR could truncate the characteristic radial flow from the Bog mound and reduce the quantity of groundwater currently flowing from the Bog to areas on the down-gradient side of the proposed roadway. There is also a possibility that during dry season conditions, groundwater flow could be directed from the roadway towards the Bog. The potential impact is expected to be medium east of Area 1 and in Area 2, where the inferred Bog mound is located on both sides of the roadway, and low to medium in Areas 3 and 5, where the down-gradient lands do not represent Bog mound. Since the SFPR roadway section in Area 4 will be constructed upon deep piles extending above ground surface, the potential impacts on groundwater hydraulics in that area are considered low. |
| Page v para 3 |
Compression of peaty sediments in the Burns Bog area (Areas 1 through 3 and Area 5) is expected to create continuous depressions along the toe of fill slopes. Without mitigative measures, groundwater could be induced to flow from the adjacent acrotelm and/or catotelm layers of the Bog strata, which could remove water from storage in the Bog and result in ecosystem disturbances similar to historical drainage ditches (resulting in an impact rating of medium). |
| Page vi para 1 |
SFPR north of the Bog the potential for SFPR roadway construction to affect groundwater quality in this area is considered to be medium. |
| Page 7 |
The EAO has recognized several factors as being crucial to the preservation of Burns Bog (Hebda et al. 2000). The EAO noted that the existence of peat-forming bog vegetation is largely dependant on groundwater and surface hydraulics, in particular the maintenance of a near-surface water table in the Bog mound. Also, the EAO report noted that the unique water chemistry (i.e., acidic and mineral poor) that supports the Bog ecosystem is partly dependent on the maintenance of a functioning “lagg” along the Bog margin. Agricultural drainage improvements were identified as the primary mechanism for water table deepening (i.e., acrotelm deepening), whereas, urban development along the Bog margin was recognized as the primary cause of “lagg” area reduction. |
| Page 7 |
The first phase was conducted from September to December 2004 and consisted of the installation and testing of 28 monitoring wells at 13 locations along the entire length of the SFPR (MW04 series wells), |
| Page 9 |
The second phase was conducted from January through March 2006 and consisted of the installation of 18 monitoring wells at 5 locations within and adjacent to Burns Bog (MW06 series wells). |
| Page 11 |
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| Page 15 |
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The base flow analysis focused primarily on major streams and watercourses considered to be fish habitat. Fifty-nine (59) streams, creeks, ditches and ravines were identified as being potentially affected by the SFPR (Figure 6). Approximately 25% of these are considered to be major creeks or ravines that are of considerable size and/or importance with respect to wetlands/bogs. |
| Page 21 para 2 |
The BC Ministry of Environment (MOE) maintains an on-line aquifer inventory mapping system Relatively more vulnerable and shallower unconfined aquifers are located in Fraser River Sediments underlying the floodplain west of Highway 91 and also along portions of the southern shoreline of the Fraser River (Figure 8). Specifically, the SFPR west of the Highway 91 is located over the South Fraser River Delta Aquifer (Class IIIA), which has high vulnerability and low to moderate usage, and the SFPR section from near 112th Street to 128th Street is located above a portion of the South Fraser River Junction Aquifer (Class IIIB), which has high vulnerability and low usage. |
| Page 21 |
Groundwater discharge from the Fraser Heights embankment is known to sustain watercourses that either directly or indirectly support fish habitat through the supply of nutrients and base water flow. |
| Page 23 para 3 |
The area of steeply sloping terrain immediately east of the Alex Fraser Bridge (Location F) includes known archaeologically sensitive sites. In this location, the water table was measured at 2.5 m-bgs in monitoring well MW04-F2 (shallow) close to the Fraser River, and 5.4 m-bgs at MW04-F1, which is situated approximately 5 m upslope (December 2004). The potential tidal influence on groundwater levels in this sensitive area are discussed further in Section 2.2.4 (Tidal Influence on Groundwater Levels in Archaeologically Sensitive Areas). |
| Page 30 para 3 |
A provision has been made to conduct three additional rounds of groundwater quality sampling over the 2006 year to characterize seasonal variations in groundwater quality. |
| Page 31 |
North edge of Burns Bog: In this study, Type 1 water was found to extend to the south edge of the developed land. The lateral extent of the lagg zone (Type 2 water) appears to be limited or completely absent, likely due to the abrupt change in land use in that area from undeveloped to developed. This pattern is inconsistent with Figure 12 of EBA (2000b), which shows the three distinct water type in this area, with the boundaries of the Type 1 and Type 2 waters located further south. |
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| Page 31 para 2 |
The nitrate concentration detected in groundwater from well MW04-G (13.5 mg/L) exceeded CSR DW standard of 10 mg/L. Well MW04-G is located downgradient of a large residential area where fertilizers may have been used. |
| Page 31 para 3 |
The magnesium concentration at MW04-L2 (127.0 mg/L) exceeded the CSR DW standard of 100 mg/L established based on taste and odour concerns. |
| Page 32 |
The following dissolved metals were detected at concentrations above the CSR IW standards:
�� Manganese in 6 of 6 monitoring wells; and
�� Iron in 2 of 6 wells (MW04-N and MW04-D1).
Boron concentrations at MW04-A (1.16 mg/L) and MW04-D1 (0.12 mg/L) exceeded the lower value of the crop-dependent IW standard, which ranges from 0.5 mg/L to 6 mg/L |
| Page 32 para 2 |
The following dissolved metals were detected at concentrations above CSR AW standards:
�� Cadmium in 6 of 16 wells (MW06-D3S, MW06-E2S, MW06-P2S, MW06-P4,
MW06-Q1, and MW06-Q3); and
�� Zinc in 2 of 16 wells (MW06-D3S and MW06-P4).Aquatic life standards for cadmium and zinc vary with hardness, because as hardness increases the toxicity of cadmium and zinc decreases. Bog groundwater is soft, so cadmium and zinc are toxic at very low concentrations. |
| Page 33 para 1 |
The following total metals were detected at concentrations above CSR DW standards:
�� Aluminum in 7 of 11 monitoring wells (all wells except for MW04-G, MW04-H,
MW04-J, and MW04-L1S);
�� Iron in 10 of 11 monitoring wells (all wells except for MW04-G);
�� Magnesium in 1 of 11 monitoring wells (MW04-L2); and
�� Manganese in 10 of 11 monitoring wells (all wells except for MW04-G). |
| Page 33 para 1 |
Xylene was detected in groundwater at three out of six monitoring wells located in agricultural and developed lands west of Highway 91 (MW04-B, MW04-M and MW04-D1). |
| Page 33 para 1 |
No hydrocarbons exceeded applicable standards at MW04-D1, located on a former landfill, despite the fact that at the time of drilling a strong hydrocarbon-like odour was noted in fill from the screened elevation (Appendix II). Additional investigations of areas where a moderate to high potential for contamination exists are being carried out under a separate scope of work. Therefore, locations where hydrocarbons were found in excess of the CSR in relatively undeveloped areas along the SFPR are not shown in plan view in this study. |
| Page 34 |
Naphthalene was detected at four locations (MW04-I, MW04-JI, MW04-L2, and MW04-L3) east of Highway 91 at concentrations well below the CSR AW standards. Benzo(a)pyrene (0.000023 mg/L) was detected at one location (MW04-F2S) east of Highway 91 above the CSR DW standard of 0.00001 mg/L but below the CSR AW standard of 0.0001 mg/L. The PAHs detected at this monitoring well may result from upgradient hydrocarbon sources from a gas station or commercial industrial property identified during the contaminated site impact assessment (MOT 2006). |
| Page 43 para 3 |
Therefore, if proposed crossing structures are not properly sealed to prevent water losses, or if structure inlets are not configured to restrict water from “recharging” the roadway fill, potential impacts (i.e., reductions) to watercourse base flow could be considered to be medium.In areas where compressible soils are present below the roadway, the hydraulic conductivity of soils adjacent to these watercourses could be reduced in response to fill pressures. |
| Page 45 para 1 |
Impacts associated with road use are primarily related to highway runoff, which has been found to contain heavy metals, suspended solids, hydrocarbons,Highway runoff has the potential to affect surface water quality and ultimately, groundwater quality. |
| Page 45 para 2 |
Heavy metals in highway runoff result primarily from particulate material outfall from vehicle exhausts. |
| Page 46 para 2 |
Hydrocarbons in highway runoff are derived from motor oil, tire wear, atmospheric fallout,and to a lesser extent, erosion of bituminous surfaces |
| Page 46 para 2 |
However, large-scale spills of hydrocarbons and other chemicals from accidents involving vehicles or tanker trucks have the potential to more significantly impact groundwater quality. |
| Page 46 para 3 |
road salt is considered to have a medium impact on groundwater quality. |
| Page 46 |
Hydrocarbons - (from spills) High Salt Medium |
| Page 47 para 2 |
The potential impact of the SFPR construction on water well quality is medium to high for dug wells and drilled wells that are improperly sealed and located in close proximity to the alignment. |
| Page 47 para 1 |
Roadway construction and operation within the five identified Areas is interpreted to represent the highest potential for impacting the Bog, due to the relative proximity of the mound margin. |
| Page 47 para 2 |
Based on the extent of the water mound inferred from the field program, the proposed roadway is aligned directly over portions of the mound east of Area 1 and in Area 2 (Figure 14). In Area 3, the proposed SFPR is potentially aligned within 50 m of the inferred mound boundary, while in Area 5, the proposed SFPR is potentially aligned within 200 m of the inferred mound boundary (Figure 14). In Area 4, the roadway alignment is similarly positioned near the edge of the inferred mound, but will not be constructed using structural fill placement. |
| Page 48 para 1 |
Soils in the vicinity of the five designated “Areas” are known to include relatively thick strata of surficial peats (Golder 2005a; Golder 2005b) and fill materials placed along roadway sections in Areas 1, 2, 3 and 5, will be located partly or entirely on peat. The existing subsurface profile in these areas will change due to consolidation of the peat, combined with peat replacement using relatively permeable fill. East of Area 1 and in Area 2, the proposed roadway fill footprint might also extend partly over the inferred mound boundary and, therefore, onto potentially functional Bog. Similarly, in Areas 3 and 5, the roadway fill footprint is expected to overlie potentially functional Bog. Following initial fill placement in Areas 1, 2, 3 and 5, groundwater is expected to continue flowing radially (overall) from the Bog mound, originating from both acrotelm and catotelm, and into the roadway fill. However, there is some potential for groundwater entering the roadway fill to assume a hydraulically preferred flow direction, within the permeable fill and parallel to the roadway alignment, resulting in a significant deflection from the characteristic radial flow path. |
| Page 48 para 2 |
Lateral deflections of the radial flow of groundwater, along the SFPR alignment, could potentially reduce the quantity of groundwater currently flowing from the Bog to areas on the down-gradient side of the proposed roadway. The potential impact is expected to be medium east of Area 1 and in Area 2, where the inferred Bog mound is located on both sides of the roadway and the function of the down-gradient portion of the Bog is partly dependent on maintenance of existing flow patterns. Impacts associated with changes to groundwater flow directions in Areas 3 and 5 are expected to be low to medium since the down-gradient lands in those areas do not represent Bog mound. |
| Page 48 para 3 |
A downward deflection of the ground surface is anticipated along both margins of the roadway fill, near the toe of the fill side slopes (Figure 14), in areas where the roadway is constructed upon compressible soils (Areas 1 through 3 and Area 5). The depression could form a continuous ditch-like feature along the roadway sections constructed near the Bog. In areas where the roadway fill is specifically located adjacent to or within the Bog mound, the depression could induce groundwater drainage from the relatively elevated acrotelm layer adjacent to the roadway. Groundwater movement, from either the acrotelm and catotelm layers into the roadway fill and/or roadside depressions, could reduce the storage of water in the Bog and increase the flow rate of surface water and groundwater from the Bog, which could deepen the mound water table. The related impacts on the Bog ecosystems could therefore be similar to some historical Bog disturbances relating to drainage ditches, although more localized, as documented by Hebda et al. (2000). Accordingly, the potential impact of drainage of Bog water into roadway depressions is considered medium. |
| Page 48 para 4 |
It is understood that the SFPR roadway section in Area 4 will be constructed upon deep piles extending above ground surface to support at-grade “deck” structures. This approach will preclude placement of a thick granular fill base and significantly reduce the overall footprint of the roadway. Therefore, consolidation of local peaty soils and formation of roadside depressions are not a concern and the potential impacts on groundwater hydraulics in Area 4 are considered low. |
| Page 49 para 4 |
In addition, there is potential that the fill material itself may release constituents that could alter the local groundwater chemistry. The associated impacts on Bog water chemistry are potentially significant in areas where the SFPR alignment is in close proximity to Type I waters. Given the relative importance to the overall Bog viability, the impacts associated with the alteration of water chemistry in Areas 1 and 2, where Type I water has been identified, are considered medium. |
| Page 50 para 1 |
While groundwater is largely expected to flow radially out from the Bog mound, limited dry-season water-level data collected at monitoring wells MW04-C2 and MW04-C3 in the southwest corner of the Bog suggests that in that area, a reversal in the groundwater flow direction (towards the bog) was apparent during dry season conditions. Continuous water-level monitoring will be conducted over 2006 to assess seasonal variations in groundwater flow patterns; however, the limited data raises the possibility that there may be reversal of groundwater flow from the SFPR towards the Bog at some locations during dry season conditions. If this were to occur, this could result in a medium impact to groundwater quality in Areas 1 and 2, where the chemistry of Type I water could be altered by mixing with terrestrial water from the road base fill. The potential impact on groundwater quality in Area 3 (where the water type is uncertain) would be low to medium, |
| Page 50 para 2 |
Another potential impact on Bog water chemistry originates from roadway stormwater runoff, which could increase the proportion of “non-bog” waters within the portion of the Bog that receive the runoff. Accordingly, the impacts to Bog water chemistry associated with stormwater runoff is considered medium for Areas 1 and 2, low to medium for Area 3, and low for the remainder of the alignment, including Areas 4 and 5. |
| Page 51 para 2 |
the potential groundwater quality impacts related to stormwater runoff from the proposed SFPR roadway into this wetland are considered to be medium. |
| Page 52 para 2 |
As currently proposed, the SFPR is aligned through a portion of the “wet” sites and; therefore, road construction will occur directly upon disturbed and possibly intact archaeological deposits, including human remains. |
| Page 55 |
Placement of a continuous (i.e., several kilometres long) roadway fill structure within the Delta Lowland area has the potential to influence both the quality and flow of groundwater associated with Burns Bog in some areas.In addition, conceptual mitigative measures are required to address the maintenance of radial groundwater flow from Burns Bog. While a number of mechanisms could be implemented to achieve this, one option is installing intermittent flow “barriers” at right angles to the alignment axis (i.e., parallel to the radial flow) to reduce the potential for groundwater to flow along the alignment (Figure 15). This approach would result in discrete “compartments” within the roadway fill that are hydraulically separated from adjacent “compartments” by low-permeability zones (i.e., barriers) comprised of natural and/or synthetic materials. As depicted in Figure 15, the low-permeability barriers would be constructed vertically within the roadway fill, extending through the full height of the fill materials. Groundwater flow originating from the up-gradient (i.e., Bog) side of the roadway would continue to flow approximately perpendicular through the roadway fill and congruently with pre-construction subsurface flow patterns. |
| Page 55 para 2 |
The impact of the SFPR on groundwater quality could be reduced by ensuring that the fill material placed as part of the road construction in sensitive areas does not release constituents that would be harmful to bog vegetation or result in a change to Bog water chemistry. This is of particular importance in Areas 1 and 2, where Type I water is present. |
| Page 55 para 3 |
The concept depicted on Figure 15 would also be effective in maintaining the current overall quantity of groundwater (i.e., flow rates) below the proposed alignment. Accordingly, the potential loss of groundwater to the down-gradient side of the roadway, which could be either agricultural lands (e.g., Area 5) or Bog mound (e.g., east of Area 1 & in Area 2), would be effectively addressed. |
| Page 55 para 4 |
Similarly, surface water “berms” could be placed within the shallow depressions along the toe of the fill slopes (Figure 15). The berms would occupy the full wetted-depth of the depressions and would be keyed-in to the “barrier” walls within the roadway fill. The “berms” would effectively retain any groundwater that has “daylighted” from the adjacent strata, thus reducing the potential for continuous drainage of either the acrotelm and catotelm layers while maintaining groundwater levels (i.e., groundwater storage) in the Bog. Water retained in the depressions would ultimately flow down-gradient through the roadway fill, within the adjacent fill “compartment”, in agreement with current shallow groundwater flow trends. The surface water flow barriers (i.e., “berms”) would be designed to allow surface water conveyance along the edge of the fill structure, as required to satisfy applicable drainage requirements. |
| Page 55 para 5 |
Maintaining current groundwater flow directions along the proposed SFPR alignment, using the combined surface and groundwater barrier concept (Figure 15), would assist in preserving the characteristic Bog mound water chemistry (Type I). Specifically, installing the vertical barriers and depression berms will assist in maintaining Bog groundwater flow directions and groundwater levels and, therefore, maintaining the current distribution of Type I water and other “transitional” or “non-bog” waters along portions of the Bog mound. Accordingly, employing mitigative measures such as those described above should reduce the potential impacts on Bog hydraulics and groundwater quality to low. |
| Page 58 para 2 |
Two aquifers located west of 128th Street are relatively shallow and unconfined, with a correspondingly high vulnerability to surface contamination. These include the South Fraser River Junction Aquifer between 112th and 128th Streets, and the South Fraser River Delta Aquifer, which underlies the entire SFPR west of 112th Street. |
| Page 59 para 4 |
West of Highway 91, in agricultural and developed lands, chloride and boron exceeded the lower range of the crop-dependent CSR IW standards at one location (MW04-A). Iron and manganese were also found above IW standards |
| Page 59 para 5 |
East of Highway 91, nitrate, aluminum, iron, magnesium, manganese and benzo(a)pyrene were found above CSR DW standards.Nitrate exceeded DW standards at monitoring well MW04-G, Benzo(a)pryene, which may be related to an upgradient hydrocarbon source, exceeded DW standards at MW04-F2S. |
| Page 59 para 6 |
Six private water wells were identified within 150 m of the SFPR that are active and currently being used for drinking water supply and other uses (i.e., household, irrigation, garden, and/or livestock). |
| Page 60 para 1 |
Consolidation of peat deposits along the overall SFPR will result in a reduction in the hydraulic conductivity of these materials. |
| Page 60 para 2 |
The potential impact of construction on watercourses crossing the alignment is medium, |
| Page 60 para 3 |
the impact of a potential hydrocarbon spill in the event of a major vehicle accident could be high; |
| Page 61 para1 |
In areas located in close proximity to the inferred Bog mound, preferential groundwater flow from Burns Bog into roadway fill associated with the SFPR could truncate the characteristic radial flow from the Bog mound and reduce the quantity of groundwater currently flowing from the Bog to areas on the down-gradient side of the proposed roadway. There is also a possibility that during dry season conditions, groundwater flow could be directed from the roadway towards the Bog. The potential impact is expected to be medium east of Area 1 and in Area 2, where the inferred Bog mound is located on both sides of the roadway, and low to medium in Areas 3 and 5, where the down-gradient lands do not represent inferred Bog mound. |
| Page 61 para2 |
Compression of peaty sediments in the Burns Bog area (Areas 1 through 3 and Area 5) is expected to create continuous depressions along the toe of fill slopes. Without mitigative measures, groundwater could be induced to flow from the adjacent acrotelm and/or catotelm layers of the Bog strata, which could remove water from storage in the Bog and result in ecosystem disturbances similar to historical drainage ditches (resulting in an impact rating of medium). |
| Page 61 para3 |
the potential for SFPR roadway construction to affect groundwater quality in this area is considered to be medium. |
