Information Needed for Waterborne Pathogens in Agricultural Watersheds

1. Information Needed for Waterborne Pathogens in Agricultural Watersheds Barry H. Rosen, Ph. D. USDA NRCS Watershed Science Institute 401 Oberlin Rd., Suite 245 Raleigh, NC 27601 barry.rosen@ftw.nrcs.usda.gov (919)-828-9658

2. Factors Affecting the Viability of Pathogens Along Transport Pathways

3. Die-off-Generally Accepted Die-off is a function of several environmental factors that reduce the population of organisms. First order decay uses the following equation: Nt/No = 10-ktwhere Nt = number of organisms at time t No= number of organisms at time t k = time in days t = first order or die-off constant (other than 1st order decay merits further examination)

4. Die-off: Soil Temperature (what can be done in winter?)

5. Die-off: Soil pH (effectiveness of land treatments)

6. Die-off: Manure Application (interface with hydrology/climate)

7. Die-off: Soil Moisture (soil type interaction with moisture content)

8. Die-off: Slope and Filter Strip Width (questionable effectiveness)

9. Conservation Practices

10. Effect of Waste Management on Organisms & Infectivity Issue: Specific rates of die-off and infectivity in storage lagoons, (aerobic & anaerobic), after field application of waste (under various scenarios), irrigation, and other existing practices (BMPs and Conservation Practices) is very poorly understood. Research requirement: Field research for understanding, improving, and optimizing waste management. Multiple researchers needed.

11. Conceptual Model of Pathogen Sources

12. Microbial Source Tracking Issue: Research efforts throughout the U.S. developing site-specific genetic libraries for source identification of the indicator bacteria, E. coli. A national repository and distribution center that collects and distributes data for matching sources would increase efficiency, enhance success and reliability and reduce costs. Recognition of regional differences anticipated. Research requirement: Establish a central source and distribution center. Develop laboratory proficiency/clearinghouse.

13. Multi-Barrier Approach

14. Import Barrier • Feeds • Prevent contamination, especially for young animals (e.g. wild mice feces contamination w/ Cryptosporidium) • Drinking Water • Prevent accidental contamination w/ wastes • Exclusion fencing from streams • New Livestock • Quarantine of new animals • People and Implements • Visitors follow biosecurity measures to reduce farm-to-farm transmission

15. Amplification Barrier Cleaning • Housing units and equipment frequently • Separate implements for feeding and cleaning • Contamination • Prevent manure to feed from foot traffic • Prevent fecal material from other animals (pets & wildlife). • Quarantine/destroy contaminated animals Treatment • Use animal health care providers for keeping animals healthy

16. Waste Stream Barrier Storage and Treatment • Stacking litter (poultry <8 days--temp. related) • Composting, manure transfer • Lagoons, pits, other storage facilities • Roof runoff management Application • Technique-(residue management, incorporation) • Climatic conditions-(dry) • Hydrologic consideration-(flow paths)

17. Export Barrier Buffers and Filter Strips (variable effectiveness) • Reduction in the volume of runoff- (increased infiltration) • Decrease in runoff velocity -(vegetative cover resistant) • Sedimentation of pathogens • Increased adsorption to soil particles and plants Constructed Wetlands Water & Sediment Control Measures Use Exclusion and Fencing

18. Prevalence of Infection (number of animals/herds infected) & Intensity of Shedding (number/gram feces) Issue: Diversity of animal operations through U.S., i.e., upstate New York dairy completely different than California dairy. No idea how this affects shedding prevalence and therefore national or regional estimates of infection may not be relevant on a watershed scale, i.e., Giardia infection in Nebraska feedlot irrelevant to very large Texas feedlot. Research requirement: Field research w/ multiple researchers

19. Risk Factors for Critical Waterborne Zoonoses Associated with Structural Designs and Human Management Issue: Modify the design of structures and management of animal operations to directly reduce the risk to public health from animal manure based on risk assessment. Research requirement: Risk assessment and subsequent design modifications for structures and management.

20. Fate and Transport Modeling Issue: As new data are generated on organism die-off under various conservation and best management practices, models are an essential part in predicting the effectiveness on a watershed scale. Building on current Stella-based bacterial dynamics modeling efforts (NRCS) would be usefully for many efforts, including TMDLs. Research requirement: Model development and enhancement coupled to previously described research efforts. Multiple researchers

21. WEND-B (Bacteria) Overall Model Objectives Enhance our UNDERSTANDING of how bacteria are processed (production, storage, application, die-off and transport) through COMPLEX watersheds. Assess consequences of management STRATEGIES for large complex watersheds.

22. Modeling Approach • View watersheds as complex DYNAMIC ECOSYSTEMS • Use MASS BALANCE concepts to account for all pathways of bacterial input to the watershed, storage, internal processes (i.e. application & die-off), and output to the drainage net. • Model created in the object-oriented STELLA dynamic simulation programming environment.

23. Model Components Agriculture Runoff & sub-surface flow Drainage Net Natural Areas Runoff & sub-surface flow Runoff & sub-surface flow Urban

24. Herd Size (+) (-) Getting Started Domestic Animals Production (of manure/bacteria) Data needed: number of animals avg lbs manure production/animal/day avg # of bacteria/lbs of manure Amount of manure/bacteria

25. Domestic Animals Animals on Pasture Production (organisms that do not reach GW or DN) Die-off Drainage Net Amt Pasturelands Surface Runoff Infiltration Drainage Net Sub-surface Flow Sub-surface Reservoir Die-off Data needed: bacterial die-off rates (pasture & GW) hydrologic simulations infiltration rates

26. Domestic Animals Storage Route(s) Production Seasonal component* Die-off Drainage Net Housing & Barnyard Waste Amt Surface Runoff Infiltration Drainage Net Sub-surface Flow Sub-surface Reservoir Die-off Data needed: bacterial die-off rates runoff volume amounts moved to storage infiltration rates Waste Storage

27. Application Routes Die-off Pasturelands Waste Storage and Treatment Amt Application Haylands Infiltration Import Export Sub-surface Reservoir Manured Croplands Die-off Sub-surface Flow Drainage Net Die-off Surface Runoff Data needed: placement and quantity of apply manure imports and exports (if any) area of land uses seasonal component* Drainage Net

28. Other Sources (+) (-) Population Size Wildlife Pasturelands Amt Production Haylands Infiltration Sub-surface Reservoir Manured Croplands Die-off Sub-surface Flow Unmanured Croplands Die-off Surface Runoff Drainage Net Die-off Drainage Net Surface Runoff Drainage Net

30. Bacteria Field Bacteria Pasture Bacteria Storage Bacteria Barnyard Fall Clean-out Spring Storage Clean-out Cows on pasture

31. Just completed conceptually the Ag component Agriculture Runoff & sub-surface flow Drainage Net Natural Areas Runoff & sub-surface flow Runoff & sub-surface flow Urban

32. Next Steps Hydrology: Simulate rainfall to get runoff and infiltration, including large storm, (>1 in 10 yr), events. Seasonality: Simulate storage of manure during the winter, with large application in spring (clean out of storage), and summer monthly applications. Temperature effects on die-off. Time Step: Use appropriate time-step to capture these events. Data for variables from the literature???