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

2. 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

3. 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

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

5. 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)

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

7. 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

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

9. 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

10. 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

11. 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

12. 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

13. Phillippi Creek Main A Discharge

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

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

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

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

19. Treatment Train
Wet Detention
Force Main
Filtration UV

21. 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

22. 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