groundwater contamination Flashcards
how do we investigate, identify and understand groundwater systems
- drill boar holes and look for surface exosure (rivers, …)
aquifer typers
Unconfimed
- no impermeable layer lying on top of the aquifer
- direct vertical hydrological (rainwater/percipitaion permiates and directly gets to aquifer) connection to surface
- important to contamination in unconfied aquifer; can impact freah water
confined
- impermeable layer on top of the aquifer
- no direct vertical connection to the surface
- groundwater not contaiminted because impermeable
- aquitard can eventually have water flow to aquifer over many years
water pollution
- considered polluted if unusabe for a purpose
- not a new issue
- just because clear does not mean its not polluted
- typical indication of pollution is smell and taste
- water moves through the grounf and inflitrates downwards
- percolates
solutes
- dissolved matters
- includes inorgani and organic matters
suspended sediments
- particulates that are within water bodies (lakes,rivers, etc)
- can include soil, algae, plankton, other substances
- impacts the quality of water
total dissolved solids (TDS)
- amount of inorganic and organic particles that are dissolved in water
- can be used an indicator of water quality
sources of contamination
- point source pollution: discharged through a discree identifiable location; easy to evaluate; ex. pipes
- nonpoint source pollution: broad diffuse sources; difficult to identofy and quantify
water quality- non point source
- non point pollution: cannot be linked to a single source, comes from a wider area
- diffuse pollution: is a policy issue in the great lakes basin; eutrophication of lake erie was linke to agricultural run off; tried to reduce non-point pollution
- diffuse pollution: represents a ‘layered’ problem” environmental degration and economic costs; ecosystem integrity and human health; human value, belifs, attitues, and behaviours
what are the major sources of groundwater contamination
- agriculture (fertilizer, pesticides)
agricultural sewage (walkerton crisis)
- may 2000
- walkeron relied on groundwater wells
- pollution from surface waters entered aquifers
- heavy rainfall in late april to early may 2000
- pollution entered groundwater wells
- ecoli contamination
- shllow aquifer
- jointed bedrock (limestone)
- poor treatment
- well operators were not trained properly and water manager withheld adverse water quality information
- government water-testing labs had been shut down duw to budget cuts, and provate labs weren’t required to submot results
- led to safe drinking act and clean water act
ontarios greenbelt
- provincially protected green space (including forests,farmlands, wetland, and watersheds)
- established in 2005
- to ensure ecological safety net
- land under greenbelt cannot be developed on
- almost built on but then went back
what would be the best type of site for a future landfills
- on thick, fine-grained sediment (low permeability)
- no fractures
-slows rates of groundwater movement - even if there is a lining, leechase is ugly liquid from landfill and will leech into environment
water scarcity
- the point at which the total imapct of all users (peoplea and institutions) affects the quantity and quality ofwater under prevaling institualtional arrangement to the extent that the deman by all sectors (evironmental, industry, agriculture, snaiation, and consumtption) cannot be satisfied fully
- may be a social construct (depends on people in area). a product of affluence, expectations and customary behaviour; or the consequences of altered supply patterns- stemming from climate chnage
