coastal pollution and water treatment ppt - willis' science · coastal pollution and water ......
TRANSCRIPT
What does the National Resource
Defense Council Say?
• CA had the nation's 17 most polluted
beaches last year, and for the 5th straight
year, the worst of those beaches were in
LA County.
• Also, those in LA County had the highest
levels of fecal material in ocean water
• 10/11/09 LBC (KABC) -- A 2 mi. long stretch of
beach in Long Beach was shut down Sunday after
10,000 gallons of raw sewage leaked into LA River
• Cause: So. Pasadena raw sewage line break
• 7/26/08: LA Times: Cleaning crews responsible for maintaining city's 760 mi. of sewer lines traced Saturday's spill in LB to an 8-inch pipe below a gated community that was clogged with cooking grease!
• 7/13/08: LA Times: A 300-gallon spill that closed several beaches was caused by vandals stuffing toilet paper down public toilets near Mother's Beach.
Raw Sewage Flows to Treatment
Facility
• Hyperion Treatment Facility in El
Segundo uses primary and secondary
treatment to clean raw sewage.
• Required by Clean Water Act of 1972.
Primary Treatment• Process of physically removing objects from
sewage.
• Tools used: Settling tanks (clarifiers), raked bar screen
Secondary Treatment• Biological process of using aerobic bacteria to break down human and food
waste, soaps and detergents.
• Tools used: aeration tanks, more clarifiers
Aeration Tank
Digesters
• Sludge that settles out of clarifiers goes into a digester.
• Here, anaerobic bacteria break down material into a nutrient rich “fertilizer.”
• And, generates methane! Use as a fuel!
Hyperion’s Biosolids• Used for growing wheat/barley in Kern County Class A biosolids, used as animal feed
Disinfection
• Ozone, chlorine, and UV light used to
kill many microorganisms before water
is released into a river/ocean.
If a Raw Sewage Line Breaks..
• Raw sewage runs off in to storm drains in streets
• Flow goes to LA River (NOT TREATED)
• NO Swimming in Long Beach!
• Big source of bacterial and viral pathogens.
Storm Drains• Provides a quick exit route for storm
water reduce flooding.
• Water not treated at treatment facility.
• Anything on streets gets carried with rain water into storm drains.
How Many do we Have in LA?
• 35,000 curb catch basins
• 1500 miles of underground pipes
• Approximately 100 mill. gallons of water
flow through LA’s storm drain system on
an average dry day.
Salmonellosis
• Caused by Salmonella enteritidis bacteria.
• Symptoms: fever, diarrhea
• Polluted surface water and standing water.
Dysentery
• Usually caused by Shigella bacteria
• Symptoms: severe diarrhea with
blood/mucus in feces.
Hepatitis A
• Caused by Hepatitis A virus
• Commonly transmitted by the fecal-oral route via contaminated food or drinking water
• Can get HAV vaccine
• Symptoms: Flu-like symptoms
• High in concentrations after rain storms.
Laws: Drinking Water
• Safe Drinking Water Act-1974
• 0 colonies per 100 mL is Maximum Contaminant Level (EPA)
Clean Water Act of 1972: requires permits
for dischargers and sets total maximum daily
loads of pollutants.
Laws: Surface Water
Clean Our Water?
• Careful monitoring
of sewage pipes.
• Education about
what should go in a
sewage pipe!
Beach Report Cards
• Heal the Bay issues
• Ratings based on enterrococcus, fecal
coliform, and total coliform tests performed
by CA Health Dept.
• http://healthebay.org/brcv2/default.aspx?ta
bid=1
• Doesn’t test for viruses: $$$
Sources
• City of LA Storm Water Program: http://www.lastormwater.org/siteorg/general/lastrmdrn.htm
• CA Dept of Health: http://www.cdph.ca.gov/HealthInfo/environhealth/water/Documents/Beaches/AppendixC.pdf
• Heal the Bay: http://www.healthebay.org
• Wikipedia: www.wikipedia.com
• LA Times: www.latimes.com
• ABC News: www.kabc.com