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HomeMy WebLinkAbout96.032014_Committee Informational Item_DisinfectionOptimization of Effluent Disinfection Ron Coss Environmental Laboratory and Ocean Monitoring Manager Orange County Beaches Summers of 1999 and 2000 Large stretch of Huntington Beach closed due to elevated concentrations of enterococci bacteria (FIB) •HBGS -Huntington Beach Generating Station •Bird droppings •Groundwater transport (spring tides) •No definitive source identified Studies recognized several potential sources: •Urban dry weather runoff •OCSD discharge •OCSD’s Coast-trunk line •Decaying infrastructure 78-inch outfall 120-inch outfall Chlorine Use and Cost, BOD, and TSS from 2002-2013 0 10 20 30 40 50 60 70 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 BOD TSS $4,308,702 $6,282,903 $5,168,258 $3,217,063 $635,632 0 2000000 4000000 6000000 8000000 10000000 12000000 Gallons Cost ($) mg/L OCSD’s Water Quality Monitoring Program Degraded Area Affected StationsOcean Bottom Monitoring Stations Impacts to Biological Community near OCSD’s Ocean Discharge Normal Operations Disinfection: Enterococci 8 February 10, 2014 3255 26 114 88 ND ND ND ND ND ND ND 29 ND 124 54 52 18 1 mile outfall 4.5 mile outfall Results of Special Study: Enhanced Disinfection ND 8.3 8.3 ND ND ND ND ND 8.3 ND ND ND ND ND ND 9.1 8.3 8.3 ND 8.3 ND ND ND ND ND ND ND 8.3 ND 8.3 8.3 ND ND ND ND ND ND ND ND ND September 10, 2012 ND ND 4 20 72 22 12 2 Potential Sources Next Steps 1.Convene Expert Panel to advise on study to decrease and ultimately cease disinfection of ocean discharge. 2.Conduct additional studies to gauge impacts to biological community and beach water quality as disinfection is decreased. 3.Recommendations to Board of Directors 4.Continued engagement with regulators to possibly remove requirement to disinfect ocean discharge from next NPDES Ocean Discharge Permit. Questions?