Science and Resource Considerations for Microbial Source Tracking

1. Science and Resource Considerations for Microbial Source Tracking Steve Jones Jackson Estuarine Laboratory University of New Hampshire Durham, NH May 5, 2006 FRESHWATER BEACH CLOSURES, FAIRLEE, VT

2. THE ISSUE Water quality at bathing beaches is a concern because of the potential for disease transmission through contact with microbial pathogens. To manage this problem, sources of the pathogens need to be identified and eliminated. Traditional source identification approaches and subsequent management actions often do not result in significant improvements in water quality. Microbial Source Tracking (MST) methods have recently been developed that allow for identification of the pollution sources that are the most significant sources or threats to public health. This new approach serves to focus management efforts and save valuable resources.

3. WHEN, WHY & HOW Should MST be Used? • What is the problem and the desired outcome? • What level of accuracy is required? • When are results needed? • What is already known about the beach? • What are the conditions of concern? • Precede or follow a sanitary survey. ARE THERE MULTIPLE OR UNKNOWN SOURCES? YES? MST!!

4. MST Study Approach • Consider area of study • Drives resource needs & expected results • Smaller area >> success • Tiered approach • Use low-cost measurements 1st • Identify probable sources • Iteratively smaller area, number of probable sources & more defined conditions of concern • Multiple MST and other methods

5. MSTDiscrimination Level Human vs. non-human? Non-human species discrimination? Types of non-human sources? Individual animals or sources? --> Dictates type of MST method required (library dependence)

6. The best results that can be accomplished with MST is an estimate of the relative contributions of different sources in the study area at the time and conditions of sampling.

7. General Characteristics of MST Methods

8. Factors Defining Advantages and Disadvantages in Comparing MST Methods

9. So, Which MST Method Should Be Used? • The results of several comparative studies that included many different MST methods suggest that all tested methods provided useful information, and often differed in capabilities depending on what type of information was desired; no method clearly superior! • Library-dependent methods: known limitations; Library independent-less available information • The best approach is to use experienced entities who encourage a tiered approach, have local/regional knowledge and can employ multiple MST methods. • Beware of promises of the SILVER BULLET!

10. Non-MST Methodsfor Fecal Contamination Optical Brighteners; UV or fluorometric detection Fecal-borne chemicals -sterols -immunoglobins -human nucleic acids Wastewater-derived chemicals -Propranolol, Ibuprofen, Caffeine -Different biodegradation rates for chimers allow for discrimination of degree of treatment of wastewater

11. Combined Use of Fecal-Borne Bacteria and Optical Brightener Detection for MST

12. Follow-up to MST Study • Information on pollution sources • Are identified sources likely? • Management strategy • Human vs. non-human sources & risk • Potential for elimination of source • EXAMPLE MST STUDY RESULTS

13. Source Species Types Identified During Wet & Dry Weather at Atlantic Coast Beaches, NH

14. Regional-Escherichia coli (EcoR1)Source Species Database 31 total species/sources; 5 TYPES

15. MST Study Sites at NH Atlantic Coast Beaches

16. Source Species Types at NH Atlantic Coast Beaches During Wet Weather: 2003