# Presentation: 438309

## Contaminant Source Tracking:    A National Perspective

- Paul Shriner
- US EPA
- Engineering and Analysis Division
- shriner.paul@epa.gov

**Notes:**
Thanks to Region 3 for this opportunity for everyone to share the recently gained knowledge and newly developed tools to help all of us make informed decisions.

## Causes of Impairment in the Nation’s Assessed Waters

- Nutrients
-  #1 stressor for lake and reservoir impairment
-  #2 stressor for the Great Lakes
-  #5 stressor in rivers and streams
- Pathogens
- #1 stressor in rivers and streams
- #4 stressor in estuaries

- Source:  National Water Quality Inventory: 2000 Report

**Notes:**
Background – 
-900,000 illnesses and 900 deaths each year from waterborne microbial infections
-actual pathogen source usually not known
-CAFOs are potential candidates for these contaminants

## Major Nitrogen Sources in the U.S.

- Source:  U.S.G.S. National Water-Quality Assessment (NAWQA) Program

**Notes:**
Livestock waste estimated to be source of 15-37% N load, and as much as 65% of the P load.

Estimated 94% N from non-point sources:
commercial– portion forms ammonia gas; conversion to nitrate in soil-highly mobile, washed by rain or leached into GW
manure – both pasture and confined, comprise a large portion of available nitrogen
Atmos depos – mostly fossil fuel combustion by utilities and transportation

## Nutrients in Agricultural Areas

- Phosphorus in nearly 80 percent of streams sampled are greater than EPA goal for preventing nuisance plant growth.
- Nitrates in about 20 percent of shallow wells sampled exceed the EPA drinking water standard.
- Elevated nitrates in karst (carbonate) areas or where soils and aquifers consist of sand and gravel.

**Notes:**
1 Where P is limiting nutrient, high levels of P trigger algal blooms.
2 This result is a concern in rural areas where shallow ground water is used for domestic supply; these domestic wells are not regulated and owners often do not know the quality of their well water or whether their wells are vulnerable to contamination.
3 These natural features enable rapid infiltration and downward movement of water and chemicals. Some of the more vulnerable areas  are the Central Valley of California, and parts of the Pacific Northwest, the Great Plains, and the Mid-Atlantic region.
- In contrast limited ground water contamination occurs in Midwest because of relatively impermeable, poorly drained soils; glacial till covers much of the region; and tile drains provide quick (and often direct!) pathways for runoff to streams.

## Pathogens

- Fecal coliforms (FC) are indicators of enteric bacterial pathogens.
- Greater FC population, the greater assumed potential that pathogens are present.
- 				However....
- There is no significant relationship between FC and certain organisms (e.g. *Crypto, *viruses, antibiotic resistant bacteria) and,
- FC counts do not tell us the source.

**Notes:**
Pathogens #1 stressor in rivers/streams.
Others indicators are  E. coli, FC/FS ratio, enterococci.
Methods for many specific pathogens inadequately developed.
Still use FC as indicator - easier to isolate, safer to work with – but it’s not necessarily the best method for source tracking.

## What are the Routes of Contamination?  

- Food-borne
- Animal-borne
- Water-borne
- Example 1: *Cryptosporidium*
- Found in many cattle herds
- 87% surface waters have Crypto oocysts
- More than half outbreaks follow heavy rainfall
- Very few outbreaks directly linked to farm animals
- Example 2: Fecal bacteria
- Manured lands not different from unmanured land provided manure was stored and aged prior to spreading
- Fresh manure applications can be as much as 80% of the FC
- Agricultural runoff exceeds bacteriological recreational standards 90% of the time

**Notes:**
Routes of contamination will improve source tracking capabilities.  
Water-borne sources of contamination largely unknown.  Animal production/manure is often suspected, but in fact rarely confirmed and more often exonerated.
		Example – Two dairies in Britain positively identified for crypto outbreak.  
But animal production in US is not same as UK or Canada; management practices are different.  Conclusions from other countries not necessarily valid in US.
Many literature / case studies conducted source tracking and attribute the problem to POTWs, CSOs, septics, swimming pools, and wildlife.
Heavy rainfall as a trigger for outbreaks suggest land management practices are crucial (JHU). 

## Recent Developments in Source Tracking

- Improved fingerprinting and detection methods
- Pathogen source tracking
- Isotope labeling
- Improved modeling
- Contaminant transport / overland processes
- Bacterial release and survivability

**Notes:**
Where are we now?
-MST and fingerprinting techniques well-established; cost still somewhat prohibitive?
-Abundance of GIS tools now used in predictive models.  Combine with indicator bacteria monitoring to validate baseline watershed conditions.
-Model logic improvements such as incorporatation of regrowth parameters for specific pathogens.

## Quantitative Information Still Needed

- Impacts from pasture livestock
- Leaky septic systems
- Urban runoff
- Combined Sewer Overflows (CSOs)
- Flow and recharge of ground water
- Wildlife, pets

**Notes:**
-Grazed livestock use 1/3 land and 50% manure in US.  Literature is diverse and nationally inconclusive on SW impacts of pastured land vs manured lands vs unmanured.
-Less value in controlling manure and fertilizer applications if CSOs contribute majority of total nitrogen/coliform to a watershed.
-Ground water provides 50% water and nitrogen to Chesapeake Bay. USGS age-dating techniques show improvements. But changes in land management in parts of Delmarva can take decades to “surface”. 
-Sources of contamination still not always confirmed: two local outbreaks suspected to be swine/poultry were shown otherwise: 
	Deep Creek Lake, MD – geese, ducks; VA Ches Bay – deer, racoons.
-One approach used by VA and PA universities is to use watershed modeling to identify critical source areas.
Follow with more detailed (and costly!) subwatershed evaluations.

## AFO / CAFO Programs

- CAFO regulatory program
- Prohibit direct contact of animals
- Minimum storage requirements
- Land application protocols
- Educational / outreach
- Coordination with USDA

**Notes:**
What are we doing now?
Revised regulatory programs increase data collection, promote improved / less expensive technology, spread knowledge to both regulated and unregulated community (Ag Compliance Center, MWPS).
EPA better understands ag (Tech Fundamentals Workshop); technical service providers better understand EPA (EPA Permit Guidance and Technical Guidance); states better understand goals (EPA sample GP, sample Technical Standards for Nutrient Management, R5 Guidance on Winter Spreading) .  
Many operations still do not realize they are CAFOs and have never heard of NPDES permits.
Reg program spotlights typically followed by NPS program, OECA, ORD, Ag Compliance Center, et al.
USDA/EPA goal of technically sound CNMPs for all AFOs, vast majority of which are not regulated. Again, results in spreading of knowledge.  Important to bringing non-AFO ag community up to speed.

## Common Treatment and Control Technology Misperceptions

- Fiction:
- A single practice can affect all control points
- “Universally affordable” treatment practices exist
- Treatment can eliminate all pollutants
- Fact:
- Phosphorus is conserved
- Up to log10 4 pathogen removal possible with biological and chemical treatment
- Secondary buffers and filters can remove 95% remaining FC

**Notes:**
No silver bullet with respect to both performance and cost.
Example: composting is not a cure-all – it will not work with all wastestreams, still have air emissions, vector magnet, not always affordable.
Most “treatment” changes the form/concentration of pollutants.  Conservation of mass applies, especially to phosphorus.
Measurable pathogen die-off through drying, temperature, sedimentation, abrupt moisture changes, UV, zooplankton predation, treatment lagoons, storage with minimum holding time, et al.  
-Consider potential thousands to millions of CFUs per g manure, x tons of manure at a single CAFO; 99.99% may not be enough.

## Multi-barrier Approach for AFOs

- Prevent pathogens entering the facility
- biosecurity plan
- Prevent pathogen propagation
- treatment
- appropriate mortality handling
- Prevent discharges
- proactive management
- adequate storage
- spill prevention and response plan
- Control export
- farm worker safety protocols

**Notes:**
More frequently endorsed is a multi-barrier preventive approach.

## Sound Nutrient Management Significantly Controls Runoff

- Adhere to setbacks from sensitive areas
- Avoid spreading during times of high potential for runoff or leaching
- Avoid saturated soils, shallow soils, flood-prone areas
- Appropriate use of no-till vs. incorporation

**Notes:**
Generally encourage site-appropriate conservation practices.
CAFO regulations establish baseline controls, such as mandatory NMPs; up to states to go further where WQS are not being met.

## Proactive Approach Warranted

- Majority of waterborne pathogen incidents do not originate from agricultural sources
- Risk of infectious diseases primarily from employees in contact with animals
- Small number of infected animals can shed huge numbers of pathogens
- Tremendous potential outbreaks warrants continued proactive approach

**Notes:**
Where are we going?
Literature suggests waterborne pathogen outbreaks other than FC not usually caused by ag; perhaps documentation is missing?  More fingerprinting of outbreaks likely.
Many cases of food-borne outbreaks caused by untreated manure.  Future focus on food handling.
More reliable source tracking through strong predictive modeling, source identification (fingerprinting), and R&D for better understanding of all “routes”.  
Reg program for NMPs required by Dec 2006. Future monitoring efforts to document progress.

## Useful Resources

- US EPA
- 	Permit Guidance and Technical Guidance
- 		http://cfpub.epa.gov/npdes/afo/virtualcenter.cfm
- 	Ag Compliance Center
- 		http://www.epa.gov/agriculture/
- US Department of Agriculture NRCS
- 		“Pathogen Management Standard”
- US Geological Survey National Water Quality Assessment
- 	 http://water.usgs.gov/nawqa/
- NRAES
- 		“Waterborne Pathogens in Agricultural Watersheds”