Water Pollution

AP Environmental Science

Point sources

Point sources

Distinct locations that pump waste into a waterway

Nonpoint sources

Pollutants that wash into the waterways when rain falls over the landscape.

Point sources examples

an effluent pipe from a factory or wastewater treatment plant

Nonpoint sources examples

Co-mingling of litter, motor oil, dog poop, and fertilizer that wash into neighborhood storm drains when it rains.

Clean Water Act

1972, established the basic structure for regulating point source discharges into navigate water ways, NPDES, providing funding to upgrade failing wastewater treatment plants

NPDES permit system

national pollutant discharge elimination system

human wastewater

Water produced by human activities such as human sewage from toilets and gray water from bathing and washing clothes or dishes.

high carbon waste, eutrophication, wastewater disease

three reasons scientists are concerned about human wastewater

high carbon waste

provides an abundant food sources for oxygen demanding microbes in the receiving waterway, which lowers the amount of dissolved oxygen

disease

Wastewater can carry a wide variety of disease-causing organisms.

Biochemical oxygen demand (BOD)

the amount of oxygen microbes in a quantity of water use over a period of time at a specific temperature.

lower BOD and higher dissolved o2 levels

what less waste pollution means

higher BOD and lower dissolved o2 levels

what higher waste pollution means

eutrophication

an abundance of fertility to a body of water

increase in nutrients

what eutrophication is caused by

fertilizers and organic waste

where an increase in nutrients comes from

rapid growth and death of algae, increased BOD by microbes

what eutrophication causes

cholera, typhoid fever, stomach flu, diarrhea, Hepatitis A

common diseases from human wastewater

septic systems

a large container that receives wastewater from the house.

Wastewater Treatment Plants

entralized plants in areas with large populations that receive wastewater via a network of underground pipes.

Manure lagoons

large, human-made ponds line with rubber to prevent the manure from leaking into the groundwater. After the manure is broken down by bacteria, it is spread onto fields as fertilizers.

Safe Drinking Water Act- (1974, 1986, 1996)

sets the national standards for safe drinking water. It is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.

primary treatment

A process that removes solids from sewage before it is discharged or treated further.

secondary treatment

the biological treatment of wastewater in order to continue to remove biodegradable waste.

chlorine

substance used in disinfection of water treatment

toxic chemicals

pesticides and industrial pollutants like heavy metals and solvents