Water Pollution

what is surface water and how much of the world’s water is it

easily accessible to humans

only 0.9%

2 types of aquifers that make up groundwater and their different concerns

unconfined: access point to the surface and source — more susceptible to contamination and environmental stressors

confined: trapped between 2 impermeable layers of rock/soil — can be depleted

water scarcity

imbalance between the supply of water and the demand for water in a region (relative supply and demand)

water stress

broad concept that considers accessibility and quality of water in addition to water scarcity

what changes are associated with a decrease in water consumption after 1985 and why did they occur

change in dominant sectors

more efficient industrial processes

recycling of water

motivation: response to increased water scarcity and environmental regulatio

why does agriculture use so much water

meat production requires a lot of food for livestock, water used as irrigation in production

life cycle assessment

environmental and health impacts of production based on how materials came to be

industries of interest

thermoelectric production uses water to cool down machines

AI production actually does not use relatively more than other anthropogenic consumption

where do most phosphorus and nutrients come from

agricultural runoff of fertilizer

wastewater treatment facilities with fecal matter contamination

Bioaccumulation factor (BAF)

ratio of a chemical concentration in tissues to that of the surrounding medium

Biomagnification factor (BMF)

ratio of a chemical’s concentration in the tissues of an organism to that of the organism’s prey

Bioconcentration factor (BCF)

specific case of BAF in which uptake is only from the surrounding medium

main concern of exposure to fecal matter in drinking water

diarrheal diseases — major cause of death for children under 5; prevents nutrient uptake important to growth and development

what does surface water pollution by wastewater treatment facilities depend on and explain

if wastewater facilities keep up with the pace of economic development in a region

• rapid growth creates more sources of industrial/agricultural pollution

• population growth increases pollution from human activity

why is surface water pollution expected to decrease in developed countries

shift to sectors that discharge less wastewater

declining or plateauing population growth wh

what do future predictions of water quality vary by

ghg emissions and socioecomic development

what are point sources regulated by

Clean Air Act and other environmental regulations

nonpoint sources of water polution

• runoff, precipitation, atmospheric deposition, land use

• highly influenced by weather patterns

  • difficult to measure and regulate

dead zone

areas where marine life cannot survive due to low dissolved oxygen from eutrophication

stages of WASH

primary and secondary water treatment

• allow physical contaminants to settle

• aeration for growth of bacteria that consume nutrients

• more settling, add disinfectant to get rid of bacteria

Clean Water Act regulation, metrics, focus

regulates discharge into water and quality standards of surface water contaminants

maximum daily load: amount of pollutants that can be discharged into a given water source, considering point and non-point sources as cumulative

focus on preventing damage to the environment

Safe Drinking Water Act (SDWA) regulation, metric, focus

regulates public water supply by protecting sources of drinking water

enforces national health-based standards for tap water

focus on preventing harm to human health