490 likes | 622 Views
Coastal Pollution. Sewage, industrial waste, soil nutrients, power plant thermal, agriculture runoff, oil seeps & mistakes, dumping, outboard motors, plastics, dumping, dredging wastes, fish processing, etc. Implications.
E N D
Coastal Pollution • Sewage, industrial waste, soil nutrients, power plant thermal, agriculture runoff, oil seeps & mistakes, dumping, outboard motors, plastics, dumping, dredging wastes, fish processing, etc.
Implications • Biological responses (individual fitness & mortality, food web structure, etc.) • Eutrophication • Habitat change • Human health • Smell
The cynical viewpoint… • The ultimate solution to pollution is infinite dilution… • So, dump pollutants in the infinite reservoir, the ocean
The cynical viewpoint… • Makes some sense • Economic & societal costs for land-based disposal are high • We can’t see it!! • But, what is “infinite dilution” • What are “safe” concentrations?
Point Sources • Discharge pollution from a specific location • sewage discharge, power plant effluent, oil produced water outlet, river, etc. • Relatively easy to identify, monitor and treat the wastes • Need discharge permit
Non-Point Sources • No specific discharge location • Run-off from ag, urban, roads, etc. • Ship leaks, bilges, etc. • Rainfall sweeps the accumulated pollutants into waterways & to the ocean • Harder to identify, treat & manage
Wastewater Discharges • Largest source of freshwater inputs to the SoCal Bight • Both treated sewage disposal & power plant coolant
Wastewater Discharges secondary primary raw
Primary Sewage Treatment • separates out the large solids, sand, and gravel • then put into settling ponds where the sludge settles out
Secondary Sewage Treatment • biological degradation of organic compounds • bacteria ‘eats’ the nutrients in the waste and decomposes them • followed by chlorine, ozone, or UV light treatment
Tertiary Sewage Treatment • removes nitrates and phosphates that could cause algal blooms • wetlands can do this naturally
Management of a Discharge • Pollutant values need to be monitored • Does the discharge meet is requirements? • Need some metric of relevant pollutant • Measure indicator organism abundance • Hope these are related to epidemiology
Beach closure: Performed by the local Agency (County, or District) Intended to protect public health Regulated through AB411 in CA
What’s measured: Indicator bacteria Total Coliform Fecal Streptococcus Fecal Coliform Escherichia Enterococcus E. Coli
Confounding Issues • Stormwater • Leaky Septic Tanks • Boats… • Birds, Dogs, Natural wildlife
Other Materials • Heavy metals • mercury, lead, nickel • highly toxic, persistent, and bio-accumulate • result from industrial activities • Organic Compounds • PCB, DDT, herbicides, etc. • DDT is most concerning
Surface sediment contamination LA County discharge off Palos Verdes
Montrose Chemical Now a superfund site Dumped TONS of DDT down sewer Ceased production in 1982 DDT has a 15 year ½ life Bioaccumulates in some organisms
Wastewater Discharges • Largest source of freshwater to SoCal Bight • Discharges include treated sewage, sludge & contaminants • Primary, secondary & tertiary levels of treatment • History of sewage technology is seen in water quality of beaches • Montrose chemical plant created the DDT problem
Bioaccumulation • Some organisms accumulate pollutants (both metals & organics) in their tissues • Biomagnification is where accumulation increases up a trophic food chain • Well known cases are Hg, PCB, Pb (also algal toxins) • Huge public health issue • Some monitoring in place
Regulations • Marine Protection, Research & Sanctuaries Act (MPRSA) • Passed in 1972 • Regulates ocean dumping • Bans radioactive, medical, sludge & industrial dumping • Regulates others
Regulations • Clean Water Act • Passed in 1972 amended in 1977 (???) • Regulates point source discharges • Requires a National Pollutant Discharge Elimination System (NPDES) permit • Compliance is mandated by monitoring
Summary • Sources of pollutants to CA Current • Mostly wastewater but others are important • Bioaccumulation & biomagnification • Regulations – MPRSA & CWA