Microbial Source Tracking in the Orange Creek Basin

Transcription

1 Microbial Source Tracking in the Orange Creek Basin Orange Creek Basin Working Group Bacteria Team Mary Paulic Stacie Greco Robin Hallbourg Paul Davis Rick Hutton Anthony Dennis Brett Goodman Sally Adkins Kim Fitzgibbons Cheryl Wapnick FDEP Alachua County EPD Alachua County EPD GRU GRU Alachua County Health Dept. GRU/Jones Edmunds City of Gainesville PBSJ PBSJ

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3 Why was this project started? For several reasons Several TMDLs adopted for fecal coliforms in 2003 Sweetwater Branch, Tumblin Creek, and Hogtown Creek 1998 Consent Decree Consent Order for GRU for not meeting spill reporting timelines GRU began MST studies as part of Consent Order Multiple investigations undertaken by local agencies as part of TMDL/BMAP implementation

4 Hogtown, Tumblin, and Sweetwater Branch drain urbanized areas. Particularly older areas of Gainesville

5 TMDL Requirements Require % reductions Hogtown Creek: 51% Reduction Sweetwater Branch: 70% Reduction Tumblin Creek: 74% Reduction Meet Class 3 standards and criteria. Fecals are an indicator group used to estimate potential for the presence of harmful bacteria and other organisms Objective is to not exceed 400 CFU/100 ml more than 10% of time or 800 CFU/100 ml in any sample Developed for entire stream

6 Water Quality Standards Must Protect Against Many Types of Pathogens Viral pathogens Norovirus Bacterial pathogens Protozoan pathogens Salmonella E. coli O157:H7 Cryptosporidium Giardia

7 Indicator Organisms Warning signal for fecal pollution Generally non pathogenic Can survive in sediment and persist in environment High levels of or exceedances of criteria indicate increased risk of illness Other indicators Enterococcus in marine waters E. coli correlated to increased risk of gastroenteritis

8 Downside to Indicators Sometimes absent when pathogens are present (false-negative) Consequence of false-negative: more people may get sick Frequently present when pathogens are absent (false-positive) Consequence of false-positive: hurts tourism, public confidence

9 Why be Concerned? Stream corridors provide recreation / parks / green space Pets and children play in or around water Fishing Stormwater / waste disposal system Potential for contact with water / People could get sick from contact

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11 Potential Sources of Fecal Coliform Bacteria: A Host of Suspects: Which apply to this basin? (or the mystery of who s s poop is it?) People Sources Illegal (illicit) sanitary connections to storm sewer system** Stormwater outfalls** Illegal sewage disposal/transient dumping Campgrounds, FSU fans, travel trailers, or other transient usage by people (homeless**) Failing septic systems** Landfills, residuals, septage spreading, or other waste disposal site Leaking or failing sewer lines**, private systems Chronic sewage spills, overflows**, lift station failure

12 Potential Sources continued Animal sources Dogs, cats, domesticated animals** Wild animals - rats, mice, raccoons, deer, pigeons, ducks, geese, wading birds, other?** Everybody contributes Stormwater (transports poop from source in watershed to stream)** Some sources can be managed, some not at all or not easily Modification of urban streams channelization concreting, pipe

13 Investigative Methods Toolbox approach no magic bullets Walk the stream DOH and ACEPD Increased watershed sampling - ACEPD Alternate indicators - Laundry whiteners, E. coli, Enterococcus, C. perfringes - ACEPD Evaluate potential for septic system contribution - DOH Sanitary sewer BMPs general good housekeeping - GRU Microbial source tracking techniques GRU and ACEPD Wildlife surveys -ACEPD

14 Walk the Streams Reality Bites

15 Hot Spot Water Quality Sampling Dry and wet periods to find hot spots Sample in observed potential problem areas Higher density of sampling sites and higher frequency Arithmetic Mean (CFU/100 ml) Median (CFU/100 ml) Geometric Mean (CFU/100 ml) Minimum (CFU/100 ml) Maximum (CFU/100 ml) Number (n) LHATWALDO , LFCNE25 9, , HOGNW23 1, , SWBNE10 54, <1 1,300, TUMSW5 2, , Rattlesnake 1, , Branch Rosewood Branch 8,890 1,100 1, , Elizabeth Creek 3,617 2,730 2, , Fecal Coliform Data June 2004 June 2007

16 2006 Alternative Indicators - ACEPD

17 Optical Brighteners Fluorescent white dye added to detergents and soap as a whitening agent,, been around since after WWII Absorb ultraviolet light and reemit light (fluoresce) as visible light in the blue light wavelengths give visual appearance of whiter clothing use fluorometer to analyze Tracks laundry water discharge, land use in basin important consideration Used for tracking illicit discharges, septic tank discharge, leaking pipes Interference with other color compounds

18 OB Cloth Traps (Wye, 2003; Nature Compass, 2006 Fabric that has not been exposed to optical brighteners. Set into a frame or other support structure. Expose for 7 78l;days in the field. Wye has used a variation of 24 to 72 hours with good results. Optical brighteners adsorb onto cloth. Tested for fluorescence. Presence or absence test.

19 OB Sample Locations 41 sites

20 OB Results 3 out of 41 sites with positive result Inexpensive Composite results Limited utility Issues with qualitative analysis Limited sensitivity Interference by dissolved organics Sedimentation Surface growth on the samplers photodegradation

21 Sanitary Sewer BMPs Smoke test for inflow/infiltration TV testing and cleaning Slip lining of pipe

22 Wastewater Collection System > 700 miles WWCS Piping > 150 Lift Stations > 13,000 Manholes

23 Possible Septic Tank Locations

24 DOH looks for separation from water table and stream and evidence of sanitary nuisance

25 Microbial Source Tracking Central Hypothesis Certain microbial species or types are associated with the gastrointestinal tract of specific animals hosts. This association can be used to track the fecal microorganism back to its host. S S S S S S S S S S S

26 Microbial Methods for Source Tracking Library dependent Library of patterns corresponding to IOs isolated from feces of host animal Geographic range???? Expensive Result is % contribution of a source

27 Library-Independent Methods Identify one specific trait or set of traits that is found only in bacteria associated with a particular host. Develop an accurate test for the marker(s) H

28 Library-Independent Approach Based on DNA Markers Polymerase chain reaction targets a specific gene & copies it Indicates presence or absence of marker

29 Indicators used Library dependent ribotyping of E. coli ribotyping,, identifies bacterial strain based on small differences in part of DNA that codes for ribosomal RNA, finger prints compared to library Library independent tests for esp gene of Enterococcus faecium Bacteroides (specific to people) enteric viruses human polyoma viruses (urine)

30 Station Map New Possum Microbial Source Tracking Study Sample Locations in the Urban Creek Watersheds - GRU = Pilot Study - Phase 2 Test Stations Hogtown Tumblin Sweetwater Branch

31 Summary of Coliform Sources -GRU I-Human and Animal, 13% Human, 11% Indeterminant 27% Dog, 14% I-Animal, 18% Bird, 18% I- Human and Animal means an indeterminant mixture of these DNA species. I-Animal similarly means only animal DNA species was in the mixture.

32 Human Markers Multiple lines of evidence multiple hits different indicators

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34 Wildlife Surveys Walked the creek to observe animal signs detailed 100 foot survey longer less detailed segment Noted pipes, homeless camps, exotics Included control site outside urban area Collected fecal coliform samples Wildlife usage common. Raccoon tracks prevalent and most abundant wildlife Human, cat, dog tracks not noted at control site, also few raccoon tracks but deer present

35 Wildlife Survey continued Low fecal counts at control, no exceedance Questionnaire sent to 249 residents asking what wildlife they saw and how they managed their pet s s waste. 37% response to survey 23% left pet waste on ground

36 Summary - Complicated Source Id Private wastewater collection system minimal if any regulation Wastewater infrastructure is part of non point source contribution in TMDL Stormwater combines all sources making it hard to id source Many sources are linked to land use and runoff Many urban streams are part of stormwater system or have been severely modified (channels or pipes) Difficult to identify parcels with septic vs sewer connection sometimes both on same parcel Storm sewers are wildlife corridors Indicator organisms can regrow in sediment, persist in environment

37 Current Activities Additional monitoring Public Education GRU grease traps Pet waste Bacteria Hot Spot Project Working with PBSJ and GRU, ACEPD, ACDOH, City of GV, DEP, UF Compilation of work completed to date Refined investigation of hot spot location BMP selection matrix

38 Fecal Coliform Hot Spots FDEP, GRU, CGPWD, ACHD, ACEPD Study