Aldergrove Aquifer Issues

Hydrogeological Assessment Phase 1 Information Review

PROPOSED GRAVEL EXTRACTION AND AQUA-FARMING OPERATION 753-264th STREET ALDERGROVE, BC

Matthew Munn

Jill Sacre

January 18, 2010

Introduction

Golder Associates Ltd. retained by Township (Sept. 2009) and prepared a Phase 1 Hydrogeological Assessment (Phase 1) report dated October 29, 2009:

Step #1 - Initial Data Review/Summary

Step #2 - Identify Data Gaps

Step #3 - Provide Recommendations for Phase 2

X

Step #1 - Initial Data Review/Summary

Step #1 - Data Summary

Property Development Plans

Application for Township Soil Removal Permit - January 2, 2009

Minutes of Owner’s Meeting with ALC - May 1, 2009



Property Development Plansx

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)


Owner’s Supplementary Information confirmed: the following property development plans/details:x

Multiple excavations ranging from 2.5 m to 6.2 m-bg Clay will be placed within the aquaculture pond excavation

to form four pond “cells” Base of aquaculture cells will be underlain by a sand layer

“drainage system” to intercept incidental leakage Buried geothermal array of unspecified depth and location


Owner’s Supplementary Information confirmed: the following property development plans/details: x

All facility ponds will initially be filled with water from an off-site source(s)

Groundwater will not be extracted on-site for facility use Waste management will include composting of fish and

worm waste at unspecified on-site locations, using clay pads to prevent leaching of compost product


Aquifer and Groundwater Information Sourcesx

Environment Canada (Halstead, 1986)

BC Ministry of Environment’s Water Resources Atlas

Township Groundwater Modelling (Golder, 2005)

Township Vulnerability Mapping (Golder, 2005)

Piteau Associates Ltd. (April 1996)

Levelton Consultants Ltd. (June 2009)

Step #1 - Data Summary (Aquifers)

Sand/gravel MoE Aquifer #15

High vulnerability to contamination (MoE)

Sand/gravel commonly exposed at ground surface

MoE Aquifer #34

Low vulnerability

Confined


X

Golder groundwater vulnerability mapping (2005) concluded the entire Site and surrounding areas have a “Very High” vulnerability index

Step #1 - Data Summary (Receptors)

25 registered wells <500 m

Unregistered wells?

17 water licence POD’s in vicinity

14 licences on PH Creek

140,000 gal/day (irrigation and stockwatering)

Step #1 Data Summary – Piteau (1996)

Drilled seven exploration holes to max. 11 m-bg

Water table measured at 5 to 6 m-bg on Property (April 9, 1996)

“Radial” flow below Property





Step #1 Data Summary - Levelton (June 2009)

Excavated three Test Holes to max. 7.3 m-bg

Water table not encountered in Test Holes (June 12, 2009)

No MW’s installed

Flow directions not confirmed

X



DATA GAP = Absence or deficiency of information required to satisfy impact assessment objectives

X



X

ALC objective: “determine precise location and depth of aquifer underlying the entire

extraction and aquaculture facilities”x

GAP = 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.



X

ALC objective: Assess “potential risk to the aquifer or use of the aquifer on other agricultural lands” x

GAP = 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.


Typical Aquifer/Groundwater Impact Assessment ObjectivesX

Characterize current groundwater resource: - Abbotsford-Sumas Aquifer thickness - aquifer water table depths (seasonal high levels) - groundwater flow directions

Identify groundwater receptors: - confirm water licence intake field locations - confirm all water well locations and intake depths

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


Typical Aquifer/Groundwater Impact Assessment ObjectivesX




UNKNOWN

X

Step #3 - Recommendations (Phase 2)

Step #3 - Phase 2 Recommendations

To address identified data gaps:X

Confirm the layout of all gravel excavation locations, secondary ponds, composting pad(s), wetlands and geothermal array

Determine which of Piteau’s 1996 MW’s are functional/viable

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 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



Confirm the location of groundwater receptors, including unregistered water supply wells and water licence

intakes

Estimate maximum allowable excavation depths, as per typical ALC requirements

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

PRIMARY CONCLUSIONSXx

Property entirely underlain by Abbotsford-Sumas Aquiferx

Unconfined = highly vulnerable to surface contaminant sources

Second deeper aquifer = low vulnerability

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

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)


Available data does not satisfy ALC requirements for provision of “conditional approval”

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

PRIMARY RECOMMENDATIONXx

Additional site groundwater exploration/monitoring and confirmation of development plans is required.

Without further investigation, potential impacts to local groundwater resources/aquifers cannot be confirmed to an acceptable 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.



Matthew Munn

Jill Sacre



Matthew Munn

Jill Sacre

Introduction

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.

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 …”

Introduction

Golder Associates Ltd. retained by Township (Sept. 2009) and prepared a Phase 1 Hydrogeological Assessment (Phase 1) report dated October 29, 2009:

Step #1 - Initial Data Review/Summary - Confirm Property development plans - Identify local groundwater resources and users/receptors

Step #2 - Identify Data Gaps - Interpret local groundwater conditions - Identify additional data required to assess potential groundwater impacts and/or fulfill agency requirements

Step #3 - Provide Recommendations for Phase 2 - To address identified data gaps


GENERALINFORMATION

Approximately 16.6 acres

Entire property within ALR

Perry Homestead Ck.

Residence, outbuildings and barns/stock buildings



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




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



Property Development Plansx

Township Meeting with Owner (September 3, 2009) - Owner informed of independent hydrogeology study - Township requested information to confirm Owner’s development plans

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)


Owner’s Supplementary Information confirmed the following property development plans/details:x

Multiple excavations are required with a combined plan area of approximately 190 m length and width

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

Clay will be placed within the aquaculture pond excavation to form four pond “cells”

Base of aquaculture cells will be underlain by a sand layer “drainage system” to intercept incidental leakage


Owner’s Supplementary Information x

All facility ponds will initially be filled with water from an off-site source(s)

Facility operations will depend entirely on incident rainfall to satisfy water requirements

Groundwater will not be extracted on-site for facility use Waste management will include composting of fish and

worm waste at unspecified on-site locations, using clay pads to prevent leaching of compost product


Aquifer and Groundwater Information Sourcesx

Environment Canada (Halstead, 1986) - Regional-scale mapping of major geological units - Review of reports and MoE well records over ~20 years

BC Ministry of Environment’s Water Resources Atlas - Regional-scale aquifer mapping and classification - Registered water supply well summary - Surface water licence summary

Township Groundwater Modelling (Golder, 2005) - Township-wide 3D numerical hydrogeological model - Interpret the extent of Township aquifers - Interpret regional-scale groundwater characteristics


Aquifer and Groundwater Information SourcesX

Township Vulnerability Mapping (Golder, 2005) - Groundwater vulnerability mapping using AVI approach - Township-wide map constructed

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

Levelton Consultants Ltd. (June 2009) - Reviewed existing hydrogeology data (excluding Piteau) - Cursory examination of Property geology (3 Test Pits)


Sand/gravel MoE Aquifer #15

High vulnerability to contamination (MoE)

Unconfined Sand/gravel

commonly exposed at ground surface

MoE Aquifer #34

Low vulnerability

Confined


X

Golder modelling (2005) identified the “Abbotsford Aquifer” as being equivalent to MoE’s Abbotsford-Sumas Aquifer

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

Golder groundwater vulnerability mapping concluded the entire Site and surrounding areas have a “Very High” vulnerability index

Step #1 - Data Summary (Receptors)

25 registered wells <500 m

10 north of PH Creek

15 west or south of Property

Unregistered wells?

17 water licence POD’s in vicinity

14 licences on PH Creek

140,000 gal/day (irrigation and stockwatering)



Sand/gravel to full depths drilled at all locations

Five holes converted to MW’s



Step #1 Data Summary - Levelton (June 2009)

Excavated three Test Holes to max. 7.3 m-bg

Primarily sand/gravel to full depths

Water table not encountered in Test Holes (June 12, 2009)

No MW’s installed

Flow directions not confirmed

Aquifer thick. estimated ~7 m



X

ALC objective: “determine precise location and depth of aquifer underlying the entire

extraction and aquaculture facilities”x

GAP = 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.



X

ALC objective: Assess “potential risk to the aquifer or use of the aquifer on other agricultural lands” x

GAP = 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.


Aquifer/Groundwater Impact Assessment Data Gaps ObjectivesX


Identify groundwater receptors: - confirm water licence intake locations - confirm all water well locations and intake depths



Aquifer/Groundwater Impact Assessment Data Gaps ObjectivesX




UNKNOWN



Confirm the layout of all gravel excavation locations, secondary ponds, composting pad(s), wetlands and geothermal array

Determine which of Piteau’s 1996 MW’s are functional/viable

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 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



Confirm the location of groundwater receptors, including unregistered water supply wells and water licence

intakes

Estimate maximum allowable excavation depths, as per typical ALC requirements

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


Property entirely underlain by Abbotsford-Sumas Aquiferx

Unconfined = highly vulnerable to surface contaminant sources

Second deeper aquifer = low vulnerability

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

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)


Available data does not satisfy ALC requirements for provision of “conditional approval”

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

PRIMARY RECOMMENDATIONXx

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.

Without further investigation, potential impacts to local groundwater resources/aquifers cannot be confirmed to an acceptable degree of certainty.



Matthew Munn

Jill Sacre

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Aldergrove Aquifer Issues