Chapter 20: Water Pollution

Tertiary or advanced sewage treatment

Special filtering processes and bleaching, chlorination

Peter Montague

environmental scientist

Developed countries

Bottom-up political pressure to pass laws

Developing countries

Little has been done to reduce water pollution

Water pollution

Change in water quality that can harm organisms or make water unfit for human uses

Nonpoint sources

Broad, diffuse areas. they are hard to identify and control as well as expensive to clean

Point sources

Located at specific places. Easy to identify, monitor, and regulate

Infectious disease organisms

contaminated drinking water

Typhoid fever

diarrhea, severe vomiting, enlarged spleen, inflamed intestine; often fatal if untreated

Chlorea

diarrhea, severe vomiting, dehydration; often fatal if untreated

Bacterial dysentery

diarrhea, bleeding; rarely fatal except in infants without proper treatment

Enteritis

severe stomach pain, nausea, vomiting; rarely fatal

Infectious hepatitis (type B)

Fever, severe headache, loss of appetite, abdominal pain, jaundice, enlarged liver; rarely fatal but may cause permanent liver damage

Poliomyelitis

Fever diarrhea, backache, sore throat, aches in limbs; can infect the spinal cord and cause paralysis and muscle weakness

Amoebic dysentery

Severe diarrhea, headache, abdominal pain, chills, fever; if not treated can cause a liver abscess, bowel perforation, and death

Giardiasis

Diarrhea, abdominal cramps, flatulence, belching, fatigue

Cryptosporidium

Severe diarrhea, cramps for up to 3 weeks, and possible death for people with weakened immune systems

Schistosomiasis

Abdominal pain, skin rash, anemia, chronic fatigue, and chronic general ill health

Ancylostomiasis

Severe anemia and possible symptoms of bronchial infection

Stratified layers

Little vertical mixing

Eutrophication

Natural enrichment of a shallow lake, estuary, or slow-moving stream. Caused by runoff into the lake that contains nitrates and phosphates

Oligotrophic lake

Low nutrients, clear water

Cultural eutrophication

Nitrates and phosphates from human sources. Farms, feedlots, streets, parking lots. Fertilized lawns, mining sites, sewage plants

PUR

chlorine and iron sulfate powder

1974 U.S. Safe Drinking Water Act

Sets maximum contaminant levels for any pollutants that affect human health

Health scientists

strengthen the law

Water-polluting companies

weaken the law

Crude and refined petroleum

Highly disruptive pollutants

The largest source of ocean oil pollution

Urban and industrial runoff from land

1989

Exxon Valdez, oil tanker

2010

BP explosion in the Gulf of Mexico

Volatile organic hydrocarbons

Kill many aquatic organisms

Primary sewage treatment

Physical process

Secondary sewage treatment

Biological process with bacteria

Tertiary or advanced sewage treatment

Special filtering processes and bleaching, chlorination

Peter Montague

environmental scientist