Urban GeologySpring 2011

Gowanus Canal

Historical use

New York City

Water pollution

Sewage treatment plants

Eutrophication

Combined sewage outflows (CSO)

Remediation

Sustainability

Gowanus Canal todayhttp://www.achildgrowsinbrooklyn.com/a_child_grows_in_brooklyn/images/2008/05/29/gowanuscanal.jpg

Sunset at Gowanus Bay in the Bay New York (1851) by Henry Gritten

1609: Henry Hudson “discovered” this area Gowanus Creek originally a navigable tidal inlet with marshes

and meadows▪ Abundant fish and wildlife, particularly clams and oysters

1600’s – 1800’s: Mills built and people began to settle the area Population grew, need for larger navigational creek and docking

area Around 1867, creek dredged to create larger canal and

surrounding marshes drained Became hub for Brooklyn’s commercial shipping activity Factories, warehouses, tanneries, coal stores, and

manufactured gas refineries Raw sewage drained into canal

1900: very polluted and smelled awful Mid 1900’s: economy changing and area

declined 1975: NYC established Gowanus Industrial

Renewal Plan for area Throughout 1900’s, attempts to flush and lessen

pollution, particularly the smell 2009: EPA declared canal superfund site. Sediments laden with heavy metals, PCBs, coal tar,

other

1929 study revealed that 10 million people dumping over 1 billion gallons of raw sewage daily between 1914 and 1926

Industries: petroleum, chemical plants, kerosene, other

Oil spills Ocean dumping

Sewerage commission started in 1903 Treatment plants greatly helped to restore life in

river and estuary by 1970s Industrial big problem: PCBs, nuclear power

plant, landfills, other chemicals 1969: National Environmental Policy Act (NEPA) set up procedural requirements for all federal

government agencies to prepare Environmental Assessments (EAs) and Environmental Impact Statements (EISs)

Clean water act in 1974 Ocean dumping banned in 1988 and 1991

1.4 billion gallons of wastewater discharged by eight million residents and workers in New York City each day

over 6,000 miles of sewer pipes; 135,000 sewer catch basins; over 494 permitted outfalls for the discharge of

combined sewer overflows (CSOs) and stormwater;

93 wastewater pumping stations that transport it to 14 wastewater treatment plants located throughout the five boroughs.

secondary effluent to flow into large ponds where algae grows and uses up the ammonia and nitrates in the water.

slow process requires very large holding ponds. algal growth is harvested and used as a

nitrogen-rich organic fertilizer

http://www.nyc.gov/html/dep/images/legacy_images/controlplants.gif

Nutrients in sewage and runoff: Nitrogen and phosphorus

Microorganisms decompose the organic matter

Generates high BOD Removes dissolved

oxygen in water BOD measures how fast

microorganisms remove oxygen

p. 256

http://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Scheme_eutrophication-en.svg/800px-Scheme_eutrophication-en.svg.png

Anoxia: near or no oxygen available Hypoxia: less than 2 ppm Many organisms need above 5 ppm

http://www.noaa.gov/features/earthobs_0508/images/deadfish.jpg

http://www.whoi.edu/cms/images/lstokey/2005/1/v43n1-sengco2en_5571.jpg

Gowanus Canal

Historical use

New York City

Water pollution

Sewage treatment plants

Eutrophication

Combined sewage outflows (CSO)

Remediation

Sustainability

Source: http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/hydrosphere/hydrologic_cycle.html

are real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. (EPA, http://epa.gov/brownfields/)

http://www.gowanusbydesign.com/GbD_site/Clean_Up.html

Combined Sewer System. During dry weather (and small storms), all flows are handled by the publicly owned treatment works (POTW). During large storms, the relief structure allows some of the combined stormwater and sewage to be discharged untreated to an adjacent water body.

Source: http://en.wikipedia.org/wiki/Combined_sewer

Source: PlaNYC 2030, 2007

Communities may implement low impact development techniques to reduce flows of stormwater into the collection system. This includes: constructing new and renovated streets, parking lots and

sidewalks with permeable paving and pervious concrete installing green roofs on buildings installing bioretention systems, also called rain gardens, in

landscaped areas Rainwater harvesting equipment collects runoff from

building roofs during wet weather for irrigating landscapes and gardens during dry weather

Graywater collection and use on site reduces sewage discharges at all times

Gowanus Canal

Historical use

New York City

Water pollution

Sewage treatment plants

Eutrophication

Combined sewage outflows (CSO)

Remediation

Sustainability

The ability to meet humanity’s current needs without compromising the ability of future generations to meet their needs.

Densely populated, with needs

Water supply – quality and quantity

Waste removal

Energy

Food

Building materials

Transportation

Cultural and aesthetic considerations

Air quality

Ozone and soot

Asthma rates

Water quality

Streams and surrounding waters

Brownfields Urban heat island Rising sea level Intensifying storms

Clean air and water Cycles and reservoirs Hazard protection Erosion control

Restore to what? Manhattan to 1609? Which ecosystem services? Create framework – hydrology, soil and rock

and vegetation (Big three)

http://www.cskills.org/focus/futureskillsoftheindustry.aspx