APES Unit 3 - Water Pollution

eutrophication

natural nutrient enrichment in water

cultural eutrophication

excessive inputs of nutrients due to human activities 

ex. algal blooms from fertilizer and animal waste runoff

dead zones

oxygen depleted zones

riparian vegetation

along a streambank

helps stop sedimentation and pollutants enter water, plants absorb some

Clean Water Act (1972)

federal law that governs/monitors water pollution

created post Lake Erie incident

sets effluent standards

EPA enforces

greatly improves water quality

Safe Drinking Water Act

EPA sets standards for drinking water quality

Groundwater protection provisions

clean zone

1st and last part of oxygen sag curve

High DO, low BOD

mayflies and most fish thrive

decomposition zone

2nd part of oxygen sag curve

lower DO, higher BOD

carp, blackfly, and midge larvae thrive

septic zone

3rd part of oxygen sag curve

no DO and very high BOD

fish are absent, sludge worms, midge and mosquito larvae

recovery zone

4th part of oxygen sag curve

DO increases, BOD lowers

fish return, but mainly still carp, blackfly, and midge larvae

BOD

biological oxygen demand - amount used by microorganism in water to decompose organic matter - LOWER IS BETTER

DO

dissolved oxygen - amount of oxygen available to fish and macroinvertebrates in the water - HIGHER IS BETTER, below 5 most aquatic life cannot survive

Biotic index

number of different species of macroinvertebrates in the water

index value>20 is great diversity

index value<10 is poor diversity

Limited riparian vegetation limits diversity

TDS (conductivity)

total dissolved solids - the measure of the amount of particulate solids that are in the water - measured in mg/L

Safe drinking water <500mg/L

Can show high mineral base

TSS (turbidity)

total suspended solids - measure of the amount of sediment in the water - lower NTU the better, higher CM the better

Can see how cloudy the water is 

pH

measure of acidity - most aquatic life 6.5-8.2

Increased fossil fuel use can lower pH to become too acidic 

Most cannot surivve

Nitrates

lower the better - from fertilizer and excess nitrates/ammonia in waste

Phosphates

lower the better - from fertilizer and excess phosphates in waste

Hardness

measure of Calcium/Magnesium in water

<250mg is acceptable for drinking

0-60mg/L soft

120-180mg/L hard

Temperature change

measure in change over 24 hour period - change is bad because warm water cannot hold oxygen

Heavy metals

lead, arsenic, copper, etc

Most must be 0 to be safe drinking water

Even the tiniest amounts can cause lots of health problems

Fecal Coliform

measure of E.coli in water - drinking water must be 0/100 colonies

Found in warm-blooded animal digestive tracts

primary

physical process that removes solids

passes through screening and settles at bottom

secondary

biological process where aerobic bacteria removes biodegradable wastes - use as food source

Removes up to 90% of organic wastes

May pass through aeration tank

effluent

liquid waste or sewage discharged into a river or the sea

Does not remove

pharmaceuticals

industrial/household chemicals

radioisotopes

some persistent pesticides

disinfection

kills disease-carrying bacteria/viruses

Usual method is chlorination, ozone, or UV light

sludge

leftover waste that has settled at bottom of tank

often toxic, but can be used as fertilizer

otherwise dumped in landfills or incinerated

hypoxic

low oxygen

anoxic

no oxygen

Lake Washington

increased amounts of sewage - containing phosphorus, which is fertilizer for algae, creating algal blooms, unclear water, dead fish, and bad odor

Lake Erie

so much pollution in water (oil), caught Cuyahoga River leading into Lake Erie on fire

led to creation of EPA and Clean Water Act

Chesapeake Bay

chicken farm runoff into Bay w/ excess nutrients

lots of nitrogen and phosphorus - creating water and air pollution to all ecosystems

Gulf of Mexico Dead Zones

seasonal hypoxia, Mississippi River runoff w/ nutrients create algal blooms