Waste Water

Municipal Sewage

• Excess nutrients

Excess Nutrients

• Caused by various forms of nitrogen and phosphates
• Found in fertilizer, plant material, detergents etc
• Necessary for plant growth
• In excess, leads to excessive growth of aquatic plants

Municipal Sewage

• Excess nutrients
• Disease carrying bacteria/viruses

Bacteria/Viruses

• Enters water through stormwater drains, sanitary sewer over flows, failing septic tanks, runoff from livestock pens, boats that dump sewage etc
• Test for a few indicator bacteria such as fecal coliforms and E. coli

Municipal Sewage

• Excess nutrients
• Disease carrying bacteria/viruses
• Toxic chemicals and metals

Toxic Chemical/Metals

• Most dangerous
• Sewage concentrates it
• Many times transformed by natural processes to more harmful substances

Minamata Disease

• A neurological disorder caused by the ingestion of large amounts of fish/shellfish contaminated by methlmercury
• From two industrial effluents in Minamata and Niigata, Japan

Chisso Factory

• Manufacturer of acetaldehyde- produced methylmercury as by product
• 1932-started dumping mercury containing waste
• 1956-Minamata Bay-1st patient with neurological symptoms of unknown cause

1965-similar epidemic in Agano River basin

• 1965-similar epidemic in Agano River basin
• Men/women excluding infants affected-suspected a type of food poisoning involving fish/shellfish
• Took 12 years to figure out that mercury was the cause.

Symptoms

• Tremors/spasms/violent convulsions
• Tunnel vision
• Slurred speech/speech and language disorders
• Sensory disorders of the limbs
• Children born with severe metal retardation