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Fecal Coliform “Hot Spots” Monitoring Stacie Greco Senior Environmental Specialist Alachua County Environmental Protection Department
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Alachua County Environmental Protection Department (ACEPD) Pollution Prevention –Petroleum Clean-up –Storage Tanks Compliance –Hazardous Waste Collection –Contaminated Sites Review Natural Resources –Environmental Planning –Environmental Review Land Conservation (Alachua County Forever) Water Resources –Hazardous Materials Management –Water Quality and NPDES Compliance
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Water Quality Monitoring Programs What are the goals of the program? Regulatory standards Timeline- short term/long term Budget constraints Quality assurance (QA/QC)
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Fecal Coliform Bacteria originating from the digestive track of warm blooded animals Indicator of fecal pollution and disease causing organisms State fecal coliform standard for Class III waters- one time maximum of 800 CFU/100ml nor exceed 400 CFU/100 ml in 10% of the samples Giardia E. Coli
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Fecal Coliform TMDLs
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Regulatory Background Total Maximum Daily Loads (TMDLs) PHASE 1Water Quality Monitoring PHASE 2 Compare Water Quality Data to Standards to Create the Impaired Waters List PHASE 3Development and Adoption of TMDLs for Waters Verified as Impaired PHASE 4 Development of the Basin Management Action Plan (BMAP) to Achieve the TMDL PHASE 5 Implementation of TMDL(s), Including Water Quality Monitoring and Assessment
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Sources of Fecal Coliform Failing septic systems Leaks and overflows from sanitary sewer systems Illegal discharges of sanitary waste Pet wastes Wildlife Re-growth in sediments
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Microbial Hot Spots Monitoring Goal: Locate and identify sources of increased fecal coliform bacteria.
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Fecal Coliform Data June 2004 – June 2007 Hot Spot Arithmetic Mean (CFU/100 mL) Median (CFU/100 mL) Geometric Mean (CFU/100 mL) Minimum (CFU/100 mL) Maximum (CFU/100 mL) Number (n) LHATWALDO8996505661004,60024 LFCNE259,008520694110128,00016 HOGNW231,97370089312011,84027 SWBNE1054,063460739<11,300,00031 TUMSW52,28681094913042,00043 Rattlesnake Branch 1,800880874567,60023 Rosewood Branch 8,8901,1001,52356132,00037 Elizabeth Creek3,6172,7302,89679010,00022
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Hot Spots Monitoring Plan Step 1: Narrow in on “hot spot” locations with inexpensive indicators (2005) Step 2: Identify sources of fecal coliform as human or non-human (2006 & 2007) Step 3: Investigate the role of wildlife (2007) Step 4: Explore the role of internal sources in the sediments (2006 – 2008)
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Fluorescent Whitening Agents (FWAs) Intensely fluorescent dyes in laundry soap –“make your whites whiter and your brights brighter” Their presence in surface waters indicates: –failing septic systems, –failing wastewater collection infrastructure, –illicit discharges, or –use of surface waters for washing laundry
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FWA Sample Locations
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FWAs Monitoring Plan Samplers were deployed at 41 sampling sites Field Parameters were recorded (pH, temp, DO, conductivity, and turbidity) Fecal coliform samples were collected Flow was measured
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FWAs Monitoring Plan Each sampler was left out for 7 days –FWAs, if present, will adsorb to the cloths –The results are a composite and reflect the conditions over the 7 day period
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FWAs Results FWAs were absent from all of the sites except the following: SiteResult 1Result 2 HOGNW8Weak PositiveNone Detected SWB331Moderately PositiveStrong Positive LHATWALDOWeak Positive SWB331 is downstream of the GRU Main St. wastewater treatment plant (WWTP) LHATWALDO is downstream of the Brittany Estates WWTP
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FWAs Discussion Inexpensive Composite results Issues with qualitative analysis –Limited sensitivity –Interference by dissolved organics –Sedimentation –Surface growth on the samplers –photodegradation
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2006 Alternative Indicators Three week sampling plan –25 sites were sampled for microbial indicators once per week for 3 consecutive weeks. –FWA samplers were left out for 7 days –Samples were archived QA/QC- –Field blank samples for each week –Wastewater also collected for each week
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2006 Alternative Indicators E. coli concentrations have been shown to correlate with increased risk of gastroenteritis in recreational water users Enterococcus commonly used as an indicator in marine waters. Clostridium Perfringins is commonly used in Europe and Hawaii
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2006 Alternative Indicators Sites were located concentrated in hot spots
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2006 Alternative Indicators
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Archived Samples- Microbial Source Tracking Methods to detect and differentiate sources of fecal pollution. –Host specific human specific molecular markers Enterococcus (esp) Bacteroides spp. Polyomavirus –4 out of 13 samples were positive for at least one human marker
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Alternative indicators did not provide enough additional source information to justify costs Storm events made the data difficult to interpret Repeated sampling needed to verify MST results Jury still out on FWAs as an indicator Alternative Indicators Discussion
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2007 Microbial Source Tracking Sampled 29 sites for three consecutive days for fecal coliform –Analyzed for 3 human specific markers and measured flow on day two –Put FWA samplers out on day one and collected on day three –Collected sediment samples for general Bacteroides spp (not human specific) All sites were under baseflow conditions
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Microbial Source Tracking Interpretation Bacteroides spp. does not persist in the environment so is indicative of recent contamination. Enterococcus (esp) is not normally detected in septic effluent- so its presence is indicative of a non-septic source Triple positive is a very strong human signature
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Microbial Source Tracking Discussion
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FWAs were not a good screening tool for MST -18 sites were positive for markers but negative for FWAs Sediments may be a source of bacteria, but difficult to correlate with the water column Frequency of MST not sufficient to identify trends –Appears to be human and non-human sources MST is very expensive and still evolving 2007 Microbial Source Tracking Discussion
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Wildlife Survey
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Future Studies Hot Spots Partnership Pet waste outreach campaign Detailed creek walks with attention to stormwater outfalls Sampling sediment traps for fecal indicators
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Questions?
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Alachua County Opportunities Internships: https://myalachuacounty.us/internships/po sitions.aspx https://myalachuacounty.us/internships/po sitions.aspx Thesis topics/Research Water Resources Website: –http://www.alachuacounty.us/government/dept s/epd/waterquality/
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