WELLS AND SURFACE WATER: INTERACTION AND INFLUENCE Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)...

WELLS AND SURFACE WATER:WELLS AND SURFACE WATER:INTERACTION AND INFLUENCEINTERACTION AND INFLUENCE

Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)[email protected]@bcgroundwater.ca

1 866 851 94141 866 851 9414

PRESENTATION OUTLINEPRESENTATION OUTLINE

ISSUES FACING WELL USERSISSUES FACING WELL USERS

INCREASED PUBLIC AWARENESS AND UNCERTAINTYINCREASED PUBLIC AWARENESS AND UNCERTAINTY

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS

GROUNDWATER VIEWPOINT (“The Well”)GROUNDWATER VIEWPOINT (“The Well”)

SURFACE WATER VIEWPOINTSURFACE WATER VIEWPOINT

PRACTICAL SCREENING TOOLSPRACTICAL SCREENING TOOLS

SUGGESTED RECOMMENDATIONS TO CLIENTSSUGGESTED RECOMMENDATIONS TO CLIENTS


INCREASED PUBLIC AWARENESSINCREASED PUBLIC AWARENESS

AND UNCERTAINTYAND UNCERTAINTY


INCREASING DEMAND FOR WATER SOURCESINCREASING DEMAND FOR WATER SOURCES Urban Development, First Nation and Private Rural SubdivisionsUrban Development, First Nation and Private Rural Subdivisions AgricultureAgriculture IndustryIndustry

COMPETING INTERESTS FOR GROUNDWATERCOMPETING INTERESTS FOR GROUNDWATER Domestic (Municipal vs. Private Utility vs. Residential)Domestic (Municipal vs. Private Utility vs. Residential) IrrigationIrrigation Fisheries and EnvironmentFisheries and Environment IndustryIndustry

RAPID PACE OF GROUNDWATER DEVELOPMENTRAPID PACE OF GROUNDWATER DEVELOPMENT Explosion of new well constructionExplosion of new well construction Limited regulation of development (excl. large-scale and/or Limited regulation of development (excl. large-scale and/or

Federal Grants)Federal Grants) Lack of follow-up monitoring to confirm sustainability of Lack of follow-up monitoring to confirm sustainability of

groundwater development and impacts on surface watergroundwater development and impacts on surface water Lack of follow-up water quality monitoring (groundwater and Lack of follow-up water quality monitoring (groundwater and

surface water)surface water)

INCREASED PUBLIC AWARENESSINCREASED PUBLIC AWARENESS IMPROVED UNDERSTANDING OF HOW SURFACE WATER AND IMPROVED UNDERSTANDING OF HOW SURFACE WATER AND

GROUNDWATER INTERACTGROUNDWATER INTERACT Groundwater is typically not “isolated” from nearby surface watersGroundwater is typically not “isolated” from nearby surface waters Soils may not adequately “filter” surface water before it recharges Soils may not adequately “filter” surface water before it recharges

groundwatergroundwater Microorganisms can be transferred from surface water to Microorganisms can be transferred from surface water to

groundwatergroundwater

INCREASED AWARENESS OF WATER QUALITY ON PUBLIC INCREASED AWARENESS OF WATER QUALITY ON PUBLIC HEALTHHEALTH

Walkerton (May 2000: 2300 sick and 7 deaths) resulted from E.Coli Walkerton (May 2000: 2300 sick and 7 deaths) resulted from E.Coli contamination of a well due to manure spreading on a local farm contamination of a well due to manure spreading on a local farm (farmer followed approved guidelines)(farmer followed approved guidelines)

Frequency of Water Advisories in BC (number in 100’s)Frequency of Water Advisories in BC (number in 100’s)

SURFACE WATERS SURFACE WATERS ANDAND GROUNDWATERS ARE VULNERABLE GROUNDWATERS ARE VULNERABLE TO CONTAMINATION AND DEPLETION FROM A VARIETY OF TO CONTAMINATION AND DEPLETION FROM A VARIETY OF SOURCES (NOT JUST HUMAN IMPACTS)SOURCES (NOT JUST HUMAN IMPACTS)

PUBLIC IS BETTER INFORMED BUT UNCERTAIN…PUBLIC IS BETTER INFORMED BUT UNCERTAIN… Is there enough to go around ? Who is protecting their water ? What Is there enough to go around ? Who is protecting their water ? What

can they do to help ? How much will it cost ?can they do to help ? How much will it cost ?

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS

Surface WatersSurface Waters

AquifersAquifers

InteractionInteraction

Ground Water Under Direct InfluenceGround Water Under Direct Influence

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Surface Waters and Aquifers -- Surface Waters and Aquifers -

WATER TABLE

UNCONFINEDAQUIFER

LEAKY AQUITARD“CONFINING LAYER”

CONFINEDAQUIFER

AQUITARD“CONFINING LAYER”

PARTIALLY-CONFINEDOR “LEAKY” AQUIFER

BEDROCKAQUIFER

LAKE WETLAND RIVER CREEK

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Surface Water / Groundwater Interaction - Surface Water / Groundwater Interaction

(Creek) -(Creek) -

WATER TABLE

UNCONFINEDAQUIFER


CONFINEDAQUIFER



BEDROCKAQUIFER


FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Surface Water / Groundwater Interaction -- Surface Water / Groundwater Interaction -

SW/GW INTERACTION IS A NATURAL PROCESS

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Natural Groundwater Movement (No Wells) -- Natural Groundwater Movement (No Wells) -

WATER TABLE

UNCONFINEDAQUIFER


CONFINEDAQUIFER



BEDROCKAQUIFER


FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Ground Water Under Direct Influence (GWUDI) - Ground Water Under Direct Influence (GWUDI)

--

WHAT IS IT ?WHAT IS IT ? Groundwater containing insects, algae and pathogens found in Groundwater containing insects, algae and pathogens found in

surface watersurface water Suggests increased potential for occurrence of Pathogens in Suggests increased potential for occurrence of Pathogens in

untreated groundwateruntreated groundwater Pathogen = “that which produces suffering” (Greek)Pathogen = “that which produces suffering” (Greek) Babies, youth and seniors are most at risk due to weaker Babies, youth and seniors are most at risk due to weaker

immune systemsimmune systems Chemotherapy, HIV and antibiotic use stresses immune system Chemotherapy, HIV and antibiotic use stresses immune system

causing increased susceptibility to effects of pathogenscausing increased susceptibility to effects of pathogens

Giardia (“Beaver Fever”) Giardia (“Beaver Fever”) CryptosporidiumCryptosporidium

FUNDAMENTAL CONCEPTSFUNDAMENTAL CONCEPTS- Ground Water Under Direct Influence (GWUDI) - Ground Water Under Direct Influence (GWUDI)

--

HOW IS IT DETECTED ?HOW IS IT DETECTED ? Microscopic Particulate Analysis (“MPA”) and Risk Microscopic Particulate Analysis (“MPA”) and Risk

RankingRanking

Correlation of water chemistry trends in surface water Correlation of water chemistry trends in surface water and groundwaterand groundwater

GROUNDWATER VIEWPOINTGROUNDWATER VIEWPOINT

(THE “WELL”)(THE “WELL”)

Effects of Well DepthEffects of Well Depth

Bedrock WellsBedrock Wells

Ground Water Under Direct InfluenceGround Water Under Direct Influence

GROUNDWATER VIEWPOINT (THE “WELL”)GROUNDWATER VIEWPOINT (THE “WELL”)- Surface Water “Influence” on a “Shallow” - Surface Water “Influence” on a “Shallow”

Well -Well -


DRAWDOWN

• RAPID “STABILIZATION”

WELL YIELD

• HIGH(DUE TO STABILIZATION)

WATER QUALITY

• SHORT-TERM SAME AS LOCAL AQUIFER

(MIXTURE OF SW AND GW)

• LONG-TERM MAY TRANSITION TO SURFACE

WATER DUE TO “ENHANCED” MIXING

INTERACTION IS VERY COMPLEX AND

MAY CHANGE CONSIDERABLY

OVER TIME !

GROUNDWATER VIEWPOINT (THE “WELL”)GROUNDWATER VIEWPOINT (THE “WELL”) - Surface Water “Influence” on a Well of - Surface Water “Influence” on a Well of

“Moderate” Depth -“Moderate” Depth -


DRAWDOWN

• DELAYED OR NO “STABILIZATION”

WELL YIELD

• MODERATED BY DELAYED STABILIZATION

AND AQUITARD

WATER QUALITY

• SHORT-TERM ISSAME AS LOCAL

AQUIFER (DIFFERENTFROM SURFACE WATER ?)

• LONG-TERM REDUCED POTENTIAL OF

SIGNIFICANT SURFACE WATER MIXING DUE TO

AQUITARD ?

• INTERACTION STILL COMPLEX BUT MORE PREDICTABLE AND CONSISTENT OVER

LONG-TERM

GROUNDWATER VIEWPOINT (THE “WELL”) GROUNDWATER VIEWPOINT (THE “WELL”) - Surface Water “Influence” on a “Deep” Well - Surface Water “Influence” on a “Deep” Well

--


DRAWDOWN

• NO “STABILIZATION”

WELL YIELD

• MODERATED BY CONTINUOUS DRAWDOWN

AND AQUITARD

WATER QUALITY

• SHORT-TERM ISSAME AS LOCAL

AQUIFER (DIFFERENTFROM SURFACE WATER)

• LONG-TERM REDUCED POTENTIAL OF SURFACE WATER MIXING DUE TO MULTIPLE AQUITARDS

• INTERACTION IS PREDICTABLE AND CONSISTENT OVER

LONG-TERM

GROUNDWATER VIEWPOINT (THE “WELL”) GROUNDWATER VIEWPOINT (THE “WELL”) - Surface Water “Influence” on a “Bedrock” - Surface Water “Influence” on a “Bedrock”

Well -Well -


DRAWDOWN

• COMPLEX WITH NO “STABILIZATION”

WELL YIELD

• LOW DUE TO FORMATION AND AQUITARDS

WATER QUALITY

• SHORT-TERM SAME AS LOCAL AQUIFER

(DIFFERENT FROM SURFACE WATER)

• LONG-TERM REDUCED POTENTIAL OF SURFACE WATER MIXING DUE TO MULTIPLE AQUITARDS

• INTERACTION IS PREDICTABLE AND CONSISTENT OVER

LONG-TERM

GROUNDWATER VIEWPOINT (THE “WELL”) GROUNDWATER VIEWPOINT (THE “WELL”) - Ground Water Under Direct Influence - Ground Water Under Direct Influence

(GWUDI) -(GWUDI) -

IS THIS REALLY A “FILTRATION” ZONE ?

CAN TRAVEL TIME BE

ADEQUATE TO DEACTIVE PATHOGENS ?

TRAVEL TIME

GROUNDWATER VIEWPOINT (THE “WELL”) GROUNDWATER VIEWPOINT (THE “WELL”) - Ground Water Under Direct Influence - Ground Water Under Direct Influence

(GWUDI) -(GWUDI) -

+

LOW RISK ?

+ Long travel time > 30 Days ? = Pathogens deactivated before reach well ?

+

+

MODERATE TO HIGH RISK ?

+ Short travel time < 30 Days ? = “Live” Pathogens may reach the well ?

+

SURFACE WATER VIEWPOINTSURFACE WATER VIEWPOINT

Surface Water DepletionSurface Water Depletion

SURFACE WATER VIEWPOINTSURFACE WATER VIEWPOINT- Surface Water Depletion and Related Effects - Surface Water Depletion and Related Effects

- -

LAKE WETLAND RIVER CREEKCREEKS

• IMPACT CAN BE SEVERE DUE TO LOW FLOW RATE

(FISH HABITAT AND THERMAL EFFECTS)

RIVERS

• IMPACT MODERATEDBY RIVER FLOW RATE

WETLANDS

• SIGNIFICANT IMPACT TO FORESHORE HABITAT CAN

OCCUR DUE TO DRYING

LAKES

•IMPACT MAY BE MODERATED BY LAKE

VOLUME AND SUBSTRATEPERMEABILITY

IMPACTS

PROPORTIONAL TO PUMPING RATE AND

PROXIMITY TO SURFACE WATER

SURFACE WATER VIEWPOINTSURFACE WATER VIEWPOINT - Timeline of Surface Water Depletion Effects - Timeline of Surface Water Depletion Effects

--RATE OF DEPLETION MAY

EVENTUALLY EQUAL PUMPING RATE !

RAPID ONSET OF DEPLETION (MINUTES TO

DAYS) !

RATE OF DEPLETION MAY ONLY BE A FRACTION

PUMPING RATE

SLOW ONSET OF DEPLETION (DAYS TO

YEARS)

PRACTICAL SCREENING TOOLSPRACTICAL SCREENING TOOLS

RECOMMENDATIONS TO CLIENTSRECOMMENDATIONS TO CLIENTS

PRACTICAL SCREENING TOOLSPRACTICAL SCREENING TOOLS - Surface Water Depletion - - Surface Water Depletion -

PRACTICAL SCREENING TOOLS & PRACTICAL SCREENING TOOLS & RECOMMENDATIONSRECOMMENDATIONS

- Public Health and GWUDI - - Public Health and GWUDI - WELLS COMPLETED IN UNCONFINED OR SEMI-CONFINED WELLS COMPLETED IN UNCONFINED OR SEMI-CONFINED

AQUIFERS AND AQUIFERS AND ANYANY WELLS LESS THAN 30 m DEEP WELLS LESS THAN 30 m DEEP Potentially vulnerable to GWUDI and infiltration of recharge from the Potentially vulnerable to GWUDI and infiltration of recharge from the

surfacesurface May show the presence of pathogens even if not GWUDI (septic fields, May show the presence of pathogens even if not GWUDI (septic fields,

livestock, wildlife and decaying matter)livestock, wildlife and decaying matter) Detailed bacteriologic testing considered a Detailed bacteriologic testing considered a necessitynecessity for community wells for community wells Detailed bacteriologic testing recommended for residential wellsDetailed bacteriologic testing recommended for residential wells

WELLS LOCATED LESS THAN 60 m (200’) FROM SURFACE WELLS LOCATED LESS THAN 60 m (200’) FROM SURFACE WATERSWATERS

Statistics clearly show increased susceptibility to GWUDIStatistics clearly show increased susceptibility to GWUDI Detailed GWUDI evaluation considered a Detailed GWUDI evaluation considered a necessitynecessity for community wells for community wells

Consider all community wells near surface water to be GWUDI until proven Consider all community wells near surface water to be GWUDI until proven otherwise !otherwise !

Work with local Health Authority in conjunction with a qualified Work with local Health Authority in conjunction with a qualified Hydrogeologist and Water Treatment SpecialistHydrogeologist and Water Treatment Specialist

Undertake regular Microscopic Particulate Analysis (“MPA”) and risk rankingUndertake regular Microscopic Particulate Analysis (“MPA”) and risk ranking Undertake monitoring program to determine correlation of water chemistry Undertake monitoring program to determine correlation of water chemistry

trends in surface water and groundwatertrends in surface water and groundwater Detailed bacteriologic testing recommended for residential wells. Detailed bacteriologic testing recommended for residential wells.

WELLS AND SURFACE WATER:WELLS AND SURFACE WATER:INTERACTION AND INFLUENCEINTERACTION AND INFLUENCE

Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)[email protected]@bcgroundwater.ca

1 866 851 94141 866 851 9414

WELLS AND SURFACE WATER: INTERACTION AND INFLUENCE Mr. Thierry M. Carriou, P.Eng. (Hydrogeologist)...

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