apes 20-3 and 20-4 and 20-5

Exxon Valdez Oil Spill

Major tanker accident in Alaska in 1989, that resulted in a major oil spill in Prince William Sound

secondary sewage treatment

a biological process where aerobic bacteria remove as much as 90% of dissolved and biodegradable oxygen-demanding organic wastes -still doesn't kill pathogens, remove POPs, or radioactive isotopes

primary sewage treatment

a physical process that uses screens and a grit tank to remove large floating objects and to allow solids like sand and rock to settle out -waste stream then flows into a primary settling tank where suspended solids settle out as sludge -removes 60% of suspended solids and 35% of oxygen-demanding organic wastes from sewage, but no pathogens, phosphates, nitrates, salts, radioisotopes, or pesticides

oxygen-depleted zone

a zone in the ocean where sedimentation and algae overgrowth reduces sunlight, kills beneficial sea grasses, uses up oxygen, and degrades habitat (algae is decomposed by bacteria, uses all the oxygen) -mostly caused by nitrate and phosphate runoff of fertilizers and animal wastes and deposition of nitrogen compounds from the atmosphere -dead fish often found in these zones -occur mostly in temperate coastal waters and landlocked seas -because of hypoxia (low oxygen levels), they contain few oxygen-consuming fish and organisms, but they have a bunch of decomposing bacteria

septic tank

an underground tank for treating wastewater from a home in rural and suburban areas -bacteria in the tank decompose organic wastes and the sludge settles to the bottom of the tank -the effluent flows out of the bottom of the tank into the ground through a field of drainpipes -soil filters out some pollutants and soil bacteria decompose biodegradable materials

wetland-based sewage treatment systems

artificial or natural wetlands are used to treat sewage and wastewater; a bunch of different plants and bacteria are used and the sludge is used for fertilizer. cheaper than conventional sewage treatment

ah.

because of the difficulty and expense of cleaning up a contaminated aquifer, preventing contamination is the least expensive and most effective way to protect groundwater resources.

oh oh oh

bottled water is often used when people are scared to drink tap water or if it's actually polluted. but it's more expensive, there's less purity requirements, and it causes environmental problems.

red tides

excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals

they flow from homes, businesses, and storm runoff through a network of sewer pipes to wastewater or sewage treatment plants. raw sewage undergoes primary and secondary sewage treatment.

how are most waterborne wastes treated in urban areas?

keep pesticides from running off by planting vegetation, using slow-release fertilizer, reducing fertilizer use, planting buffer zones of vegetation between cultivated fields and nearby surface water, using manure, etc

how can farmers reduce surface water pollution from nonpoint sources?

-require industries and businesses to remove toxic and hazardous wastes from water sent to municipal sewage treatment plants -encourage industries to reduce or eliminate use and waste of toxic chemicals -require or encourage more households, apartments, and offices to eliminate sewage outputs by switching to composting toilet systems (convert feces into a soil-like humus that can be used as fertilizer) -wetland-based sewage treatment systems

how can we improve the conventional sewage treatment system to prevent toxic and hazardous chemicals from reaching sewage treatment plants and thus from getting into sludge and water discharged from plants?

-toxic gases and liquids are released during their manufacture -greenhouse gases and other air pollutants are emitted by fossil fuels burned tom are them and deliver them -withdrawing water for bottling can deplete aquifers

how does bottled water cause environmental problems?

-volatile organic hydrocarbons immediately kill some especially in larval forms -other chemicals in oil form tar-like global that float and coat feathers of birds and fur of marine mammals (destroys their natural heat insulation and buoyancy, causing them to drown or die of exposure from loss of body heat) -heavy oil components that sink to the ocean floor or wash into estuaries can smother bottom-dwelling organisms or make them unfit for human consumption -can also kill coral reefs

how does oil pollution affect aquatic organisms?

when a well is drilled into aquifers where soils and rock are naturally rich in arsenic. some rivers that are used for drinking water are also contaminated naturally, having originated in springs that have high levels of arsenic. also, mining and ore processing can release arsenic into drinking water supplies. it increases risk of cancer by a lot.

how does toxic arsenic contaminate drinking water? what's the big deal with it?

disinfection chlorine can react with organic materials in water to form small amounts of chlorinated hydrocarbons, which are bad

kills disease-carrying bacteria and some viruses in sewage treatment -usually done by chlorination (what's a problem with this?)

preventing sewage

reducing water pollution requires _______________ it, working with nature to treat ______________, cutting resource use and waste, reducing poverty, and slowing population growth.

bleaching

removes coloration before discharge in sewage treatment

US Safe Drinking Water Act of 1974

requires the EPA to establish national drinking water standards called maximum contaminant levels, for any pollutants that may have adverse effects on human health

the clean water act

sets standards for allowed levels of key water pollutants and requires polluters to get permits limiting how much of various pollutants they can discharge into aquatic systems

watersheds

several cities have avoided building expensive water treatment facilities by investing in protection of the forests and wetlands in the _____________ that provide their water.

land

the great majority of ocean pollution originates on _________ and includes oil and other toxic chemicals and solid wastes, which threaten aquatic species and other wildlife and disrupt marine ecosystems.

-toilet-to-tap systems or systems that purify sewage to be drinking water (complex + expensive) -little devices like filters and bottles in developing countries (simple)

there are simple and complex ways to purify drinking water. likeee?

pollution prevention!

there are simple ways and complex ways to purify drinking water, but protecting it through _____ is the least expensive and most effective strategy.

advanced / tertiary sewage treatment

uses a series of specialized chemical and physical processes to remove specific pollutants left in the water after primary and secondary treatment -most commonly uses special filters to remove phosphates and nitrates from wastewater before it's discharged into surface waters to help reduce nutrient overload -not widely used bc it's expensive

discharge trading policy

uses market forces to reduce water pollution in the us -a permit holder can pollute at higher levels than allowed in its permit if it buys credits from permit holders who are polluting below their levels

-find substitutes for toxic chemicals -keep toxic chemicals out of the environment -install monitoring wells near landfills and underground tanks -require leak detectors on underground tanks -ban hazardous waste disposal in landfills and injection wells -store harmful liquids in aboveground tanks with leak detection and collection systems -pump to surface, clean, and return groundwater to aquifer (expensive) -inject microorganisms to clean up the contamination (less expensive but still costly) -pump nanoparticles of inorganic compounds to remove the pollutants

what are some methods for preventing and cleaning up contamination of groundwater?

-prevent groundwater contamination -reduce nonpoint runoff -reuse treated wastewater for irrigation -find substitutes for toxic pollutants -work with nature to treat sewage -practice the 3 R's of resource use (reduce, reuse, recycle) -reduce air pollution -reduce poverty -slow population growth

what are some methods for preventing and reducing water pollution?

-reduce input of toxic pollutants -separate sewage and storm lines -ban dumping of wastes and sewage by ships in coastal waters -ban ocean dumping of sludge and hazardous dredged material -regulate coastal development, oil drilling, and oil shipping -require double hulls for oil tankers -improve oil-spill cleanup capabilities -use nanoparticles on sewage and oil spills to dissolve the oil or sewage -require secondary treatment of coastal sewage -use wetlands, solar-aquatic or other methods to treat sewage

what are some methods for preventing excessive pollution of coastal waters? cleaning it up?

applying less fertilizer, injecting fertilizer below the soil surface, using controlled-release fertilizers that have water-insoluble coatings, planting strips of forest and grasslands along waterways to soak up excess nitrogen, and restoring and creating wetlands between crop fields and streams -can also improve flood control, preventing release of nitrogen from floodplains, and upgrading sewage treatment to reduce discharges of nitrates into waterways

what are some preventive measure to take to prevent oxygen-depletion zones from growing? they grow because of more fertilizer runoff usually that have nitrates and phosphates that cause harmful algal blooms btw.

if they're installed incorrectly or maintained wrong, they can cause sewage to back up into homes or pollute nearby groundwater and surface water.

what are some problems with septic tanks?

-fertilize garden and yard plants with manure or compose instead of commercial inorganic fertilizer -minimize use of pesticides, especially near bodies of water -prevent yard wastes from entering storm drains -don't use water fresheners in toilets -don't flush unwanted medicines down the toilet -don't pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground

what are some ways I can help reduce water pollution?

to reduce the flow of pollutants from land and air from streams emptying into these waters

what is the key to protecting the oceans?

not tanker accidents, but urban and industrial runoff from land (much of it from leaks in pipelines and oil-handling facilities) -waste oil is dumped, spilled, or leaked onto the land or into sewers by cities, industries, and people changing motor oil

what is the largest source of ocean oil pollution?

preventing oil pollution, because we can only clean up like 15% of oil.

what's the best way to reduce harm from oil spills?

cannot

when groundwater becomes contaminated, it _____________ cleanse itself of degradable waste as fast as flowing surface water does. groundwater flows so slowly that contaminants aren't diluted and dispersed effectively. groundwater is typically colder, making chemical reactions slower and DO low so not a lot of decomposing bacteria.

red, brown, or green toxic tides

when runoffs of sewage and agricultural wastes into coastal waters introduce large quantities of nitrate and phosphate plant nutrients, which cause explosive growths of harmful algae (harmful algal blooms) -release toxins that damage fisheries, kill fish-eating birds, poison seafood, etc.

refined oil.

which takes longer for populations of marine life to recover from, exposure to large amounts of crude oil or exposure to refined oil?

when a pollutant from a leaking underground storage tank or other source contaminates groundwater, it fills the aquifer's porous layers of sand, gravel, or bedrock like saturating a sponge. the slowly flowing groundwater disperses the pollutant in a widening plume of contaminated water. if this plume reaches a well, toxic pollutants can get into drinking water and irrigation water.

why is it hard to remove groundwater contaminants?

because the oceans in deeper waters can dilute, disperse, and degrade large amounts of raw sewage and other types of degradable pollutants.

why might it be safer to dump sewage sludge and most other harmful wastes into the deep ocean than to bury them on land or burn them in incinerators? (this is disputed)