What is Groundwater

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• What is Groundwater?
• Originates as precipitation of which some
  percolates down to
• recharge aquifers.
• Nearly all water that is derived from wells or
  springs. Groundwater
• provides 22 (approximately 750,000 people)
  percent of the Province's
• population with drinking water, comprises 9
  percent of total water
• consumption in the Province
• Often the only available or economically viable
  high quality potable water source for domestic
  use (B.C. Environment, 1994).
• More than 90 percent of the world's total
  supply of drinkable water.

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SNOW
RAIN
EVAPORATION
EVAPOTRANSPIRATION
RUN OFF
LAKE
OCEAN
STREAM
SOURCES OF GROUNDWATER - THE HYDROLOGICAL CYCLE
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133 I C (12)
Classification Component                      
                                               
                                                  
                  
134 IA(14)
Ranking Component                              
                                        
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FLOW CHART
6. Monitor, evaluate report plan annually
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STEP 1- PLANNING TEAM FORMATION AND
RESPONSIBLITIES

• Adequate representation, 4-6 persons
• Business,environmental,public works,
  municipal, academic
• Request key stakeholders
• Public education
• Review existing information-What do you have?
• Develop objectives
• Guide Step 2 Delineation of the WHPA

STEP 2 DELINEATE WELL CAPTURE ZONE (WHPA)

• Classify and assess aquifer vulnerability
• Hire a groundwater consultant if required
• Calculate the well capture zones
• Delineate the WHPA

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Visual Modflow 3D Modeling Capture Zone
Analysis
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METHODS FOR CALCULATING CAPTURE ZONES
Fixed Radius Method Analytical Methods
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CALCULATION OF THE AFFECTED AREA- TIME OF TRAVEL
(TOT)

• An idea of time for contaminants to reach
  well(s)
• Capture zone divided into smaller areas
• Usually 50 day, 1 year, 5 year and 10 year
  TOTs
• Setting priorities
• Microorganisms (bacteria, viruses, Giardia,
  etc.), inorganic chemicals
• (nitrate, arsenic, metals, etc.) and organic
  chemicals (solvents, fuels,
• pesticides, etc.).

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• How Can Groundwater Become Contaminated?
• Downward percolating precipitation encounters a
  source of contamination which
• may dissolve some of that contaminant and
  carry it to the aquifer.
• Contaminant may enter the aquifer some distance
  up gradient and move towards
• the well.
• Contaminants can be lumped into three
  categories microorganisms (bacteria,
• viruses, Giardia, etc.), inorganic chemicals
  (nitrate, arsenic, metals, etc.) and
• organic chemicals (solvents, fuels,
  pesticides, etc.).
• Contamination from highly visible features such
  as landfills, gas stations, industry
• or agriculture.
• Contaminants can come from common activities
  such as septic systems, lawn
• and garden chemicals, pesticides applied to
  highway right-of-ways, storm water
• runoff, auto repair shops, beauty shops, dry
  cleaners, medical institutions, photo
• processing labs, etc.
• A very small amount of some chemicals in
  drinking water can raise health concerns.

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EFFECT OF SURFICIAL DEVELOPMENT ON GROUNDWATER
TYPICAL BC VALLEY
BROADCAST AND POINT SOURCES OF POLLUTION
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SITE SCENARIOS
WELL LOCATION DIAGRAM
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Wellhead Protection Not!
Small community Groundwater Supply Wells
Winter livestock paddocks
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ECONOMIC CONSIDERATIONS

• The total economic value of an aquifer can be
  represented
• as follows
• TEV Vx Vi
• The value of a groundwater resource can also
  be defined
• as the present value of the resource
  discounted into the
• future over a specified time period where ?
  is the discount
• rate
• TEV ?tT V(t)/(1 ?)t
• A further way of defining an aquifers worth
  is to discount its
• current value (R) into the future
• TEV R R/(1?) R/(1 ? )2 R/(1 ?)3
  
• Average BC Interior water well (no
  distribution)
• Domestic 6000
• Municipal 24,000

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Ekaca Eocene Kamloops Group Calc-alkaline Rocks
SITE LOCATION
uTRNvb Upper Triassic Nicola Group volanics and
basalts
MiPlCvb-Miocene to Pleistocene Chilcotin Group
Basaltic Volcanic Rocks
LTrJ gd Lower Triassic Jurassic granodiorite
intrusive
Bedrock Geology BCGS Scale 1 250,000
PLHal Pleistocene alluvium
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Regional Fault
SITE LOCATION
Till Veneer
Till Blanket
Fine Grained GlaciaLacusterine Sediments
Surficial Geology BCGS Scale 1250,000
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108 Mile Aquifer System Scale 150,000
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108 MILE LAND DEVELOPMENT OVERVIEW
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Well 1
Sepa Lake
Well 2
108 MILE SUBDIVISION DETAIL
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108 MILE WATER SYSTEM CAPTURE ZONES
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Well 2
108 MILE WATER SYSTEM
Looking north west across Sepa Lake toward Well 1
Well 1 looking southeast across Sepa Lake
Looking southwest from peninsula toward
subdivision
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108 MILE ANALYTICAL CHEMISTRY
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DIAGRAM OF ZONING IN THE VICINITY OF COMMUNITY
WELLS
RECREATIONAL
RESIDENTIAL (SMALL LOT)
COMMUNITY WELL LOCATION
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ANAYLSIS OF WATER QUALTIY

• SAMPLING PROCEEDURE
• Well is purged, chemically stabilized, and
  water samples are collected
• Field measurements of water quality
  parameters dissolved oxygen, conductivity,
  redox potential, total dissolved solids and
  temperature
• Microscopic Particulate Analysis (MPA) test
  procedure involves filtering 2,080 L raw
  groundwater through a 1.0µ filter and
  transported to MB Labs in Sydney BC within 24
  hours of collection for analysis of the physical
  and chemical properties

GROUND WATER UNDER DIRECT INFLUENCE (GWUDI)
EVALUATION BC Ministry of Health adopts the
Province of Ontario Guidelines as set out in
Hydrogeological Study to Examine Groundwater
under Direct Influence of Surface Water (GWUDI)
October 2001 PIBS 4167E

• GWUDI WELLS classified as having incomplete or
  undependable subsurface filtration of surface
  water and infiltrating precipitation based on
• total coliforms or exhibits periodic EColi
• located within 50 meters or 50 day subsurface
  TOT from surface water if completed in overburden
  and meets one of the following - drawing water
  from an unconfined aquifer - drawing water from
  formations within 15 meters of surface - rapidly
  changing hydraulic gradients in surface water
  when wells are pumped - chemical water quality
  parameters are more consistent with nearby
  surface water than local groundwater or
  fluctuate significantly and rapidly in response
  to climate or surface water changes

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• CALCULATION OF EFFECTIVE INSITU INFILTRATION
• Particle count must show the water consistently
  contains significantly less than 100 particles
  per ml in the 10µ or greater size range
• Hydrogeologist can confirm the particle count is
  not likely to change during storm season or
  other regular environmental changes and
• the raw water characterized by good
  microbiological quality.

Subsurface travel time between the neighbouring
creek based on groundwater flow using the Darcian
equation Vk i/nwhere k is the saturated
conductivity from well capacity testing, i is
the hydraulic gradient n is the effective
porosity
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