WATER

Schedule

• Assignment 3 now posted – due May 3rd

• Water quality, part two – 1 day • Atmospheric issues – 2-3 days • Environmental health – 1 to 1 ½ days • Land-use issues – 1 ½ - 2 days • Waste-related issues – 1 to 1 ½ days If we have time: • Coastal issues – 1 day

Water pollution today

• Regulated but not all contaminants are monitored • Not all waterways swimmable • Newest issues with Clean Water Act: – Regulates draining or filling of wetlands – Also unfunded mandates: requirements by government to do something but without funded support – Stop pollution so it doesn’t have to be regulated

1 Gauging water pollution • Watershed approach: – area of land where all of the water that is under it or drains off of it goes into the same place – EPA monitors water quality by watersheds, not individual rivers – http://iaspub.epa.gov/waters10/attains_nation_cy.control?p_report_type=T

Local watersheds • Escatawpa Watershed – Mobile, Washington, George, Greene, Jackson, Wayne • Mobile Bay Watershed – Baldwin, Mobile • Mobile-Tensaw Watershed – Baldwin, Mobile, Washington

EPA guidelines

• Pollutants measured as the total maximum daily loads (TDML) for each pollutant – Amount of a pollutant that a water body can receive from point and nonpoint sources – TDMLs can change as knowledge about a pollutant increases (arsenic TDML used to be 50 ppb) • Nonpoint source pollution difficult to reduce – Runoff from contaminated surfaces pollute water

2 Alabama Water Quality

Oxygen sag • Dissolved oxygen content (DO) – indicator of aquatic health • Oxygen sag – created at point of inflow of water high in organic waste – Change the population of aquatic life

3 Nutrient enrichment

• Occurs naturally or by humans • Adds nutrients to water – Fertilizers – Untreated sewage – Increase algae growth

Algal blooms

• Water becomes: –Cloudy –Smells –Tastes bad • Rapid increase in algae – Harmful algal blooms – toxic (i.e. red tide) – Not always human-caused • Can lead to a collapse of the aquatic ecosystem – Plants and algae die – Decomposers deplete oxygen – Lake is dead – no life

Human-caused eutrophication

• Eutrophication – increase in nutrient levels and biological productivity • Cultural eutrophication: human-caused increase in biological productivity or rather water pollution caused by excessive plant nutrients

4 • Result: Nitrates and phosphates stimulate “blooms” of algae – Also from untreated sewage • Oxygen decreases – taken by algae • Bacteria also increases • Happen to Lake Erie in 1960s-1970s

Dead zones • Where rivers dump nutrients into estuaries and larger water bodies • Called hypoxic zone – oxygen-starved • Approx. 200 dead zones world wide • Baltic Sea - largest • Gulf of Mexico – 2nd largest

Baltic Sea Dead Zone

Gulf of Mexico Dead Zone • Noticed in 1980s by shrimp boat crews – large areas with no aquatic life (hypoxic - i.e. no oxygen) • $250 - $450 million/year fish industry • From agricultural runoff from farms in Mississippi River water basin – One to 2 weeks after heavy spring rains – oxygen levels decreased – Pesticide use increases zone • 6,000-7,000 square miles (average) – Reduce pesticide use = reduce dead zone

5 Summer

Winter

Groundwater

• 95% of US rural population depend on wells • Do not assume groundwater is clean – Water moves through aquifers, picking up contaminants

Groundwater contamination • EPA estimates 1.2 trillion gallons of contaminated water seep into the ground every day – Septic tanks, landfills, farms, feedlots, spills, wastes, fuel tank leaks

6 MTBE

• Methyl tertiary butyl ether: suspected carcinogen – Gasoline additive used since 70s to reduce the amount of carbon monoxide and unburned hydrocarbons – Health dangers confirmed in late 90s

MTBE

• Estimated 250,000 underground tanks leading • Additive phased out (replaced with ethanol) • Tainted water still moving through aquifers

Ocean pollution

• Also called marine pollution • Typically begins on land – Can include trash, sediment, toxic chemicals – Mostly nonpoint source pollution • Affects marine ecosystems – Coral requires clean water to grow – Predator/prey food chain – contaminants move up food chain, accumulate in organisms – Kill marine life – toxic chemicals and trash

7 Ocean pollution • Sometimes from unintentional sources – Fort Lauderdale tire reef – artificial reef created in 1972, tires tied together – Cleanup began in in 2007 to remove tires • Wash up on beaches • Ties broken • Destroying natural reefs • Leaching toxins? – Other tire reefs experiencing problems

Ocean pollution • Common divisions: – Plastic marine debris – Garbage patches – Tsunami debris • Clarity, quality, and temperature also a problem – Clarity affects reefs and some marine life • Sediment – Quality – toxic pollution (Dead Zone) – Temperature – thermal changes

Ocean dumping • Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA) – regulated dumping in waters (including international for US-flagged vessels) • Led to eventual ban (~1991) of dumping of sewage sludge within 12 miles of US coastline – 12-mile dumping ground: 19th Century to 1991 – 106-mile dumping ground: 1988 to 1992

8 Ocean dumping

• Cruise ships can dump raw sewage outside 3 miles off US shore – Amendment proposed to change to 12 miles – Black water/grey water • Ships do have technology to treat sewage on board • Rating: http://www.foe.org/cruise-report-card

Ocean pollution – marine debris

• “Any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment” (either fresh or saltwater) • Problem: “Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health”

Plastic marine debris • Main type of trash in oceans – Estimate (unconfirmed) 90% of ocean garbage is plastic – Includes plastic bottles, takeout containers, pipes, drinking straws, plastic bags – Rarely sinks • Will eventually break into very small pieces – Degradation is slower in water – Rarely fully decompose

9 Garbage patches • “Landfills” that exist in the ocean – created by trash moving within ocean gyre • Most famous: Great Pacific Garbage Patch – First mentioned in 1997 – Eastern Garbage Patch floats between Hawaii and California (2x bigger than Texas) – Western Garbage Patch forms east of Japan and west of Hawaii

Japan tsunami debris • Different from normal marine debris – includes organics (wood), boats, houses, cars • Left Japan March 2011 • No longer a debris field – too spread out • Heavier items sank

April 3, 2012

• Could be ~1.5 million tons floating towards US

10