Aldergrove Aquifer Issues

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A presentation by Golder Associates to Township of Langley Council on a proposed Aldergrove fish farm, Jan. 18, 2010.

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Aldergrove Aquifer Issues

  1. 1. Hydrogeological Assessment Phase 1 Information Review <br />PROPOSED GRAVEL EXTRACTION AND AQUA-FARMING OPERATION 753-264th STREET ALDERGROVE, BC<br />Matthew Munn<br />Jill Sacre<br />January 18, 2010<br />
  2. 2. Introduction<br />Golder Associates Ltd. retained by Township (Sept. 2009) and prepared a Phase 1 Hydrogeological Assessment (Phase 1) report dated October 29, 2009:<br /><ul><li>Step #1 - Initial Data Review/Summary
  3. 3. Step #2 - Identify Data Gaps
  4. 4. Step #3 - Provide Recommendations for Phase 2 </li></li></ul><li>X<br />Step #1 - Initial Data Review/Summary<br />
  5. 5. Step #1 - Data Summary<br />Property Development Plans<br /><ul><li>Application for Township Soil Removal Permit - January 2, 2009
  6. 6. Minutes of Owner’s Meeting with ALC - May 1, 2009</li></li></ul><li> Step #1 - Data Summary<br />
  7. 7. Step #1 - Data Summary<br />Property Development Plansx<br /><ul><li>Supplementary Owner Information (September 9, 2009) - Several hand-drawn figures - Written responses to Township questions - Copy of Piteau Associates Ltd. 1996 “hydrogeological assessment” report (confidential) </li></li></ul><li> Step #1 - Data Summary<br />Owner’s Supplementary Information confirmed: the following property development plans/details:x<br /><ul><li> Multiple excavations ranging from 2.5 m to 6.2 m-bg
  8. 8. Clay will be placed within the aquaculture pond excavation to form four pond “cells”
  9. 9. Base of aquaculture cells will be underlain by a sand layer “drainage system” to intercept incidental leakage
  10. 10. Buried geothermal array of unspecified depth and location</li></li></ul><li> Step #1 - Data Summary<br />Owner’s Supplementary Information confirmed: the following property development plans/details:<br />x<br /><ul><li> All facility ponds will initially be filled with water from an off-site source(s)
  11. 11. Groundwater will not be extracted on-site for facility use
  12. 12. Waste management will include composting of fish and worm waste at unspecified on-site locations, using clay pads to prevent leaching of compost product</li></li></ul><li> Step #1 - Data Summary<br />Aquifer and Groundwater Information Sources<br />x<br /><ul><li> Environment Canada (Halstead, 1986)
  13. 13. BC Ministry of Environment’s Water Resources Atlas
  14. 14. Township Groundwater Modelling (Golder, 2005)
  15. 15. Township Vulnerability Mapping (Golder, 2005)
  16. 16. Piteau Associates Ltd. (April 1996)
  17. 17. Levelton Consultants Ltd. (June 2009)</li></li></ul><li> Step #1 - Data Summary (Aquifers)<br /><ul><li> Sand/gravel MoE Aquifer #15
  18. 18. High vulnerability to contamination (MoE)
  19. 19. Sand/gravel commonly exposed at ground surface
  20. 20. MoE Aquifer #34
  21. 21. Low vulnerability
  22. 22. Confined</li></li></ul><li> Step #1 - Data Summary (Aquifers)<br />X<br /><ul><li> Golder groundwater vulnerability mapping (2005) concluded the entire Site and surrounding areas have a “Very High” vulnerability index </li></li></ul><li> Step #1 - Data Summary (Receptors)<br /><ul><li> 25 registered wells <500 m
  23. 23. Unregistered wells?
  24. 24. 17 water licence POD’s in vicinity
  25. 25. 14 licences on PH Creek
  26. 26. 140,000 gal/day (irrigation and stockwatering)</li></li></ul><li> Step #1 Data Summary – Piteau (1996)<br /><ul><li> Drilled seven exploration holes to max. 11 m-bg
  27. 27. Water table measured at 5 to 6 m-bg on Property (April 9, 1996)
  28. 28. “Radial” flow below Property</li></li></ul><li> Step #1 Data Summary – Piteau (1996)<br /><ul><li> Drilled seven exploration holes to max. 11 m-bg
  29. 29. Water table measured at 5 to 6 m-bg on Property (April 9, 1996)
  30. 30. “Radial” flow below Property</li></li></ul><li> Step #1 Data Summary - Levelton (June 2009)<br /><ul><li> Excavated three Test Holes to max. 7.3 m-bg
  31. 31. Water table not encountered in Test Holes (June 12, 2009)
  32. 32. No MW’s installed
  33. 33. Flow directions not confirmed</li></li></ul><li>X<br />Step #2 - Identify Data Gaps<br />
  34. 34. Step #2 - Identify Data Gaps<br />DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives<br />X<br />
  35. 35. Step #2 - Identify Data Gaps<br />DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives<br />X<br /><ul><li> ALC objective: “determine precise location and depth of aquifer underlying the entire extraction and aquaculture facilities”xGAP = Site exploration to-date (Piteau & Levelton) lacks sufficient data to accurately estimate or confirm either the thickness of the Abbotsford-Sumas aquifer or current groundwater depths within the proposed development areas.</li></li></ul><li> Step #2 - Identify Data Gaps<br />DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives<br />X<br /><ul><li> ALC objective: Assess “potential risk to the aquifer or use of the aquifer on other agricultural lands” xGAP = Risk assessment requires confirmation of current water table depths, local groundwater flow directions and location of all local groundwater receptors/users, including all registered and unregistered wells,water licences and watercourses. </li></li></ul><li> Step #2 - Identify Data Gaps<br />Typical Aquifer/Groundwater Impact Assessment Objectives<br />X<br /><ul><li> Characterize current groundwater resource: - Abbotsford-Sumas Aquifer thickness - aquifer water table depths (seasonal high levels) - groundwater flow directions
  36. 36. Identify groundwater receptors: - confirm water licence intake field locations - confirm all water well locations and intake depths
  37. 37. Characterize development-groundwater interactions: - excavation depths relative to water table - drainage system depths relative to water table - locations of excavations and ponds - locations of geothermal array and compost pad </li></li></ul><li> Step #2 - Identify Data Gaps<br />Typical Aquifer/Groundwater Impact Assessment Objectives<br />X<br /><ul><li> Characterize current groundwater resource: - Abbotsford-Sumas Aquifer thickness - aquifer water table depths (seasonal high levels) - groundwater flow directions
  38. 38. Identify groundwater receptors: - confirm water licence intake field locations - confirm all water well locations and intake depths
  39. 39. Characterize development-groundwater interactions: - excavation depths relative to water table - drainage system depths relative to water table - locations of excavations and ponds - locations of geothermal array and compost pad </li></ul>UNKNOWN<br />
  40. 40. X<br />Step #3 - Recommendations (Phase 2)<br />
  41. 41. Step #3 - Phase 2 Recommendations<br />To address identified data gaps:<br />X<br /><ul><li> Confirm the layout of all gravel excavation locations, secondary ponds, composting pad(s), wetlands and geothermal array
  42. 42. Determine which of Piteau’s 1996 MW’s are functional/viable
  43. 43. Drill four to eight additional on-site MW’s on Property perimeter and within confirmed gravel extraction areas, to confirm Aquifer thickness and facilitate groundwater monitoring program
  44. 44. Continuously monitor on-site groundwater levels to evaluate water table response to rainfall, determine groundwater flow directions, confirm water table depths and seasonal high water table position</li></li></ul><li> Step #3 - Phase 2 Recommendations<br />To address identified data gaps:<br />X<br /><ul><li> Confirm the location of groundwater receptors, including unregistered water supply wells and water licence intakes
  45. 45. Estimate maximum allowable excavation depths, as per typical ALC requirements
  46. 46. Analyze combined Property development details and groundwater monitoring data and identify potential on-site and off-site sources for groundwater hydraulic impacts and/or groundwater quality impacts</li></li></ul><li>PRIMARY CONCLUSIONS<br />Xx<br /><ul><li> Property entirely underlain by Abbotsford-Sumas Aquiferx
  47. 47. Unconfined = highly vulnerable to surface contaminant sources
  48. 48. Second deeper aquifer = low vulnerability
  49. 49. Confirmed and projected water depths (Piteau, 1996) infer proposed excavation depths of 4.5 to 6.2 m will directly intercept the Aquifer water table
  50. 50. Historic groundwater flow directions (Piteau, 1996) infer that groundwater below the site potentially supplies registered and unregistered wells, water licences and a natural receptor(s)</li></li></ul><li>PRIMARY CONCLUSIONS<br />Xx<br /><ul><li> Available data does not satisfy ALC requirements for provision of “conditional approval”
  51. 51. Available information is insufficient to characterize potential on-site or off-site groundwater impacts related to either the gravel extraction or aquaculture components of proposed development </li></li></ul><li>PRIMARY RECOMMENDATION<br />Xx<br /><ul><li> Additional site groundwater exploration/monitoring and confirmation of development plans is required.</li></ul>Without further investigation, potential impacts to localgroundwater resources/aquifers cannot be confirmed to anacceptable degree of certainty. This could be completed as Phase 2 of the Township’s “independent hydrogeology study”, or be required of others, to identify potential impacts to local groundwater flow, local groundwater quality and local groundwater users/receptors.<br />
  52. 52. Hydrogeological Assessment Phase 1 Information Review <br />PROPOSED GRAVEL EXTRACTION AND AQUA-FARMING OPERATION 753-264th STREET ALDERGROVE, BC<br />Matthew Munn<br />Jill Sacre<br />
  53. 53. Hydrogeological Assessment Phase 1 Information Review <br />PROPOSED GRAVEL EXTRACTION AND AQUA-FARMING OPERATION 753-264th STREET ALDERGROVE, BC<br />Matthew Munn<br />Jill Sacre<br />
  54. 54. Introduction<br />Township resolution (July 20, 2009) commissioned an “independent hydrogeology study” to identify and evaluate potential impacts to groundwater resources resulting from gravel extraction and aqua-farming activities proposed for the property at 753 - 264th Street, Aldergrove BC.<br />ALC issued agreement-in-principle (May 7, 2009) with conditions the Owner assess “ … any potential risk to the aquifer or use of the aquifer on adjacent lands …(and) determine the precise location and depth of the aquifer underlying the entire extraction and aquaculture facilities …” <br />
  55. 55. Introduction<br />Golder Associates Ltd. retained by Township (Sept. 2009) and prepared a Phase 1 Hydrogeological Assessment (Phase 1) report dated October 29, 2009:<br /><ul><li>Step #1 - Initial Data Review/Summary - Confirm Property development plans - Identify local groundwater resources and users/receptors
  56. 56. Step #2 - Identify Data Gaps - Interpret local groundwater conditions - Identify additional data required to assess potential groundwater impacts and/or fulfill agency requirements
  57. 57. Step #3 - Provide Recommendations for Phase 2 - To address identified data gaps </li></li></ul><li> Step #1 - Data Summary<br />GENERALINFORMATION <br /><ul><li> Approximately 16.6 acres
  58. 58. Entire property within ALR
  59. 59. Perry Homestead Ck.
  60. 60. Residence, outbuildings and barns/stock buildings</li></li></ul><li> Step #1 - Data Summary<br />Property Development Plans<br /><ul><li>Application for Township Soil Removal Permit - January 2, 2009 - 147,000 m3 gravel removal from unspecified 5 acre area - Sketch identifies a single large aquaculture pond and three small ponds for overall facility water management</li></li></ul><li> Step #1 - Data Summary<br />
  61. 61. Step #1 - Data Summary<br />Property Development Plans<br /><ul><li>Minutes of Meeting with ALC - May 1, 2009 - Owner’s “proposed facility layout” identifies four 84 m x 23 m aquaculture ponds, two ancillary ponds for water quantity management and a wetland area for managing water quality - Maximum excavation depth of 6.7 m noted</li></li></ul><li> Step #1 - Data Summary<br />
  62. 62. Step #1 - Data Summary<br />Property Development Plansx<br /><ul><li>Township Meeting with Owner(September 3, 2009) - Owner informed of independent hydrogeology study - Township requested information to confirm Owner’s development plans
  63. 63. Supplementary Owner Information (September 9, 2009) - Several hand-drawn figures, including scaled cross sections through each proposed pond area - Written responses to Township questions relating to facility water management and on-site waste management - Copy of Piteau Associates Ltd. 1996 “hydrogeological assessment” report (confidential) </li></li></ul><li> Step #1 - Data Summary<br />Owner’s Supplementary Information confirmed the following property development plans/details:x<br /><ul><li> Multiple excavations are required with a combined plan area of approximately 190 m length and width
  64. 64. Excavation depths will vary: - aquaculture ponds: 6.2 m - water detention and overflow ponds: 4.5 m - wetlands area: 2.5 m deep - geothermal array: unspecified depth and location
  65. 65. Clay will be placed within the aquaculture pond excavation to form four pond “cells”
  66. 66. Base of aquaculture cells will be underlain by a sand layer “drainage system” to intercept incidental leakage </li></li></ul><li> Step #1 - Data Summary<br />Owner’s Supplementary Information <br />x<br /><ul><li> All facility ponds will initially be filled with water from an off-site source(s)
  67. 67. Facility operations will depend entirely on incident rainfall to satisfy water requirements
  68. 68. Groundwater will not be extracted on-site for facility use
  69. 69. Waste management will include composting of fish and worm waste at unspecified on-site locations, using clay pads to prevent leaching of compost product</li></li></ul><li> Step #1 - Data Summary<br />Aquifer and Groundwater Information Sources<br />x<br /><ul><li> Environment Canada (Halstead, 1986) - Regional-scale mapping of major geological units - Review of reports and MoE well records over ~20 years
  70. 70. BC Ministry of Environment’s Water Resources Atlas- Regional-scale aquifer mapping and classification - Registered water supply well summary - Surface water licence summary
  71. 71. Township Groundwater Modelling (Golder, 2005) - Township-wide 3D numerical hydrogeological model - Interpret the extent of Township aquifers - Interpret regional-scale groundwater characteristics </li></li></ul><li> Step #1 - Data Summary<br />Aquifer and Groundwater Information Sources<br />X<br /><ul><li> Township Vulnerability Mapping (Golder, 2005) - Groundwater vulnerability mapping using AVI approach - Township-wide map constructed
  72. 72. Piteau Associates Ltd. (April 1996) - Examined geology and groundwater depths within a formerly proposed 35 acre gravel extraction area - Directly explored water table depths within central and western Property areas
  73. 73. Levelton Consultants Ltd. (June 2009) - Reviewed existing hydrogeology data (excluding Piteau) - Cursory examination of Property geology (3 Test Pits)</li></li></ul><li> Step #1 - Data Summary (Aquifers)<br /><ul><li> Sand/gravel MoE Aquifer #15
  74. 74. High vulnerability to contamination (MoE)
  75. 75. Unconfined
  76. 76. Sand/gravel commonly exposed at ground surface
  77. 77. MoE Aquifer #34
  78. 78. Low vulnerability
  79. 79. Confined</li></li></ul><li> Step #1 - Data Summary (Aquifers)<br />X<br /><ul><li> Golder modelling (2005) identified the “Abbotsford Aquifer” as being equivalent to MoE’s Abbotsford-Sumas Aquifer
  80. 80. Modelling also identified a deeper aquifer (Aldergrove Quadra) below the Property that is separated from the Abbotsford- Sumas Aquifer by a 40 to 50 m thick silt/clay layer
  81. 81. Golder groundwater vulnerability mapping concluded the entire Site and surrounding areas have a “Very High” vulnerability index </li></li></ul><li> Step #1 - Data Summary (Receptors)<br /><ul><li> 25 registered wells <500 m
  82. 82. 10 north of PH Creek
  83. 83. 15 west or south of Property
  84. 84. Unregistered wells?
  85. 85. 17 water licence POD’s in vicinity
  86. 86. 14 licences on PH Creek
  87. 87. 140,000 gal/day (irrigation and stockwatering)</li></li></ul><li> Step #1 Data Summary – Piteau (1996)<br /><ul><li> Drilled seven exploration holes to max. 11 m-bg
  88. 88. Sand/gravel to full depths drilled at all locations
  89. 89. Five holes converted to MW’s
  90. 90. Water table measured at 5 to 6 m-bg on Property (April 9, 1996)
  91. 91. “Radial” flow below Property</li></li></ul><li> Step #1 Data Summary - Levelton (June 2009)<br /><ul><li> Excavated three Test Holes to max. 7.3 m-bg
  92. 92. Primarily sand/gravel to full depths
  93. 93. Water table not encountered in Test Holes (June 12, 2009)
  94. 94. No MW’s installed
  95. 95. Flow directions not confirmed
  96. 96. Aquifer thick. estimated ~7 m</li></li></ul><li> Step #2 - Identify Data Gaps<br />DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives<br />X<br /><ul><li> ALC objective: “determine precise location and depth of aquifer underlying the entire extraction and aquaculture facilities”xGAP = Site exploration to-date (Piteau & Levelton) lacks sufficient data to accurately estimate or confirm either the thickness of the Abbotsford-Sumas aquifer or current groundwater depths within the proposed development areas.</li></li></ul><li> Step #2 - Identify Data Gaps<br />DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives<br />X<br /><ul><li> ALC objective: Assess “potential risk to the aquifer or use of the aquifer on other agricultural lands” xGAP = Risk assessment requires confirmation of current water table depths, local groundwater flow directions and location of all local groundwater receptors/users, including all including registered and unregistered wells, water licences and watercourses. </li></li></ul><li> Step #2 - Identify Data Gaps<br />Aquifer/Groundwater Impact Assessment Data Gaps Objectives<br />X<br /><ul><li> Characterize current groundwater resource: - Abbotsford-Sumas Aquifer thickness - aquifer water table depths (seasonal high levels) - groundwater flow directions
  97. 97. Identify groundwater receptors: - confirm water licence intake locations - confirm all water well locations and intake depths
  98. 98. Characterize development-groundwater interactions: - excavation depths relative to water table - drainage system depths relative to water table - locations of excavations and ponds - locations of geothermal array and compost pad </li></li></ul><li> Step #2 - Identify Data Gaps<br />Aquifer/Groundwater Impact Assessment Data Gaps Objectives<br />X<br /><ul><li> Characterize current groundwater resource: - Abbotsford-Sumas Aquifer thickness - aquifer water table depths (seasonal high levels) - groundwater flow directions
  99. 99. Identify groundwater receptors: - confirm water licence intake field locations - confirm all water well locations and intake depths
  100. 100. Characterize development-groundwater interactions: - excavation depths relative to water table - drainage system depths relative to water table - locations of excavations and ponds - locations of geothermal array and compost pad </li></ul>UNKNOWN<br />
  101. 101. Step #3 - Phase 2 Recommendations<br />To address identified data gaps:<br />X<br /><ul><li> Confirm the layout of all gravel excavation locations, secondary ponds, composting pad(s), wetlands and geothermal array
  102. 102. Determine which of Piteau’s 1996 MW’s are functional/viable
  103. 103. Drill four to eight additional on-site MW’s on Property perimeter and within confirmed gravel extraction areas, to confirm Aquifer thickness and facilitate groundwater monitoring program
  104. 104. Continuously monitoring groundwater levels in all MW’s to evaluate water table response to rainfall, determine groundwater flow directions, confirm water table depths and seasonal high water table position</li></li></ul><li> Step #3 - Phase 2 Recommendations<br />To address identified data gaps:<br />X<br /><ul><li> Confirm the location of groundwater receptors, including unregistered water supply wells and water licence intakes
  105. 105. Estimate maximum allowable excavation depths, as per typical ALC requirements
  106. 106. Analyze combined Property development details and groundwater monitoring data and identify potential on-site and off-site sources for groundwater hydraulic impacts and/or groundwater quality impacts</li></li></ul><li>PRIMARY CONCLUSIONS<br />Xx<br /><ul><li> Property entirely underlain by Abbotsford-Sumas Aquiferx
  107. 107. Unconfined = highly vulnerable to surface contaminant sources
  108. 108. Second deeper aquifer = low vulnerability
  109. 109. Confirmed and projected water depths (Piteau, 1996) infer proposed excavation depths of 4.5 to 6.2 m will directly intercept the Aquifer water table
  110. 110. Historic groundwater flow directions (Piteau, 1996) infer that groundwater below the site potentially supplies registered and unregistered wells, water licences and a natural receptor(s)</li></li></ul><li>PRIMARY CONCLUSIONS<br />Xx<br /><ul><li> Available data does not satisfy ALC requirements for provision of “conditional approval”
  111. 111. Available information is insufficient to characterize potential on-site or off-site groundwater impacts related to either the gravel extraction or aquaculture components of proposed development </li></li></ul><li>PRIMARY RECOMMENDATION<br />Xx<br /><ul><li> Additional site groundwater exploration/monitoring and confirmation of development plans is required. This could be completed as Phase 2 of the Township’s “independent hydrogeology study”, or be required of others, to identify potential impacts to local groundwater flow, local groundwater quality and local groundwater users/receptors.</li></ul> Without further investigation, potential impacts to local groundwater resources/aquifers cannot be confirmed to an acceptable degree of certainty. <br />
  112. 112. Hydrogeological Assessment Phase 1 Information Review <br />PROPOSED GRAVEL EXTRACTION AND AQUA-FARMING OPERATION 753-264th STREET ALDERGROVE, BC<br />Matthew Munn<br />Jill Sacre<br />

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