Sources, Transport, Fate Treatment Methodologies BMP Case Studies Raymond Kurz, Ph.D. Program Manager, West Florida Sciences Sarasota, Florida

Expertise Needed to Solve Microbial Contamination Problems in Stormwater Environmental Microbiology/Bacterial Source Tracking Stormwater Modeling and Treatment System Design Watershed Management Public Health Ecological Sciences (wildlife ecology) Water/Sediment Quality Monitoring and Data Analysis Wastewater Treatment Evaluations and Design TMDLs

Average Concentration of Fecal Coliform Bacteria in Stormwater? Sources Birds Mammals Reptiles Livestock Pets Sediments Humans Sewer lines Septic tanks Average Concentration of Fecal Coliform Bacteria in Stormwater? 15,000-22,000 cfu/100ml

Transport Direct wastewater outfalls Indirect outfalls (septic systems to groundwater intercepted by ditches/creeks) Stormwater runoff (overland flow) Ditches Pipes Rivers/Creeks Tides

Tides El Jobean, Charlotte County Septic systems along canal Lipp (2000) found inverse correlation between tide stage and bacteria concentrations Tidal prism created transport mechanism FC (cfu/100ml) Tide (ft)

Source Tracking Flow Diagram (from USEPA, 2005 (draft)

JEA Source Tracking Decision Tree START Putative Source = Ruminant Intensive Site Sampling: Indicator Suite Fluorometry Low Numbers Low Fluorometry High Numbers of Any Indicator Species Low Numbers High Fluorometry Ruminant- specific Bacteroides PCR Using Bacteroids STOP (except control) PCR for E. faecalis Human-specific PCR Positive Test No Evidence for Fecal Problem Negative Test Putative Human Source Positive Test Negative Test Human- specific Bacteroides & Enterococcus PCR STOP STOP No Putative Human Source Positive Test Library-based Enterococcus Source Identification Source = Ruminant Negative Test Postive Test Positive Test Library-based Enterococci Source Identification Source = Human Human- & Ruminant- Specific Bacteroides PCR Source = Ruminant Source = Human Positive Test Link Observed Source from Sanitary Survey Positive Test Link to Observed Source from Sanitary Survey Link to Observed Source from Sanitary Survey Source = Ruminant Source = Human Source = Ruminant Source = Human Link to Observed Source from Sanitary Survey Link to Observed Source from Sanitary Survey Link to Observed Source from Sanitary Survey Link to Observed Source from Sanitary Survey Other Source Categories

BMP Case Studies SWFWMD Phillippi Creek Atlantic WWTP Celery Fields Siesta Key Myrtle Beach

SWFWMD BMP Evaluation (Kurz, 1998) Sand Filtration – 65% Pulsed export of bacteria initially Wet Detention – 70-98% 5 day shallow pond greater removal than 14-day deep pond Alum (jar tests) – 99% Bacteria (and viruses) still viable in floc after several days

Phillippi Creek WBID 1937 Posted for “no swimming” since mid 1990s Verified Impaired for FC Suspected source = septic systems Other sources = stormwater, package WWTPs Poorly drained soils, proximity of drainfields to creek Miles of drainage canals

Phillippi Creek Septic Tank Replacement Program 14,000 septic systems to be replaced over next 7-10 years Expected reduction in FC in surface waters (creek) Ongoing monitoring using optical brighteners linked with FC samples to assess effectiveness

Off-line Treatment and Disposal (Reuse) Atlantic WWTP – being decommissioned Feasibility Study to evaluate potential for surface/stormwater treatment and distribution to reuse Parameters of interest: FC, color, iron Historical flow analysis (underway) 100% removal of FC and nutrient loads

Phillippi Creek Main A Discharge

Wet Detention Celery Fields, Sarasota County 500 acre stormwater detention facility Flood storage Water quality Wetland mitigation Recreational use

Fecal coliform removal (concentration based method) = 47 to 58% 7 of 24 events still above threshold

Siesta Key Beach Beach advisory – “no swim” Follow up BST study – non-human Feasibility study – divert discharge location, disinfection system Treatment Train Approach

Sources Sediments in pipe Sediments and organic matter in ditch to beach Birds at outfall to beach

Treatment Train Wet Detention Force Main Filtration UV

Myrtle Beach Construct outfalls offshore of beach (1,000 ft) Dilution, move discharge away from recreational area Three outfalls - construction cost to the city = approximately $24 million Permitting? Recurrence? UV treatment being considered

Process Perform FC/Enterococcus sampling Perform source tracking Evaluate sources and methods to control source (sediments, wildlife, illicit discharge, diffuse discharge) Evaluate costs and constructability Grant funding? TMDL waterbody? BMAP? Implement Monitor