Science key to Oklahoma’s poultry litter case
Posted on Monday, March 3, 2008
A key part of Oklahoma’s effort to ban poultry litter in the Illinois River watershed hinges on a developing, often-doubted science known as microbial source tracking.
The tracking research of professor Jody Harwood is the most important aspect of Oklahoma’s effort to ban poultry litter spreading in the watershed, said Robert George, a Fayetteville lawyer who represents Springdale-based Tyson Foods Inc.
“It’s a very important card in their house of cards,” George said.
Oklahoma seeks a preliminary injunction in U. S. District Court at Tulsa to ban poultry litter spreading on farm fields in the watershed. A hearing on the matter ran from Feb. 19-22 and picks up again for another three days, starting today.
Oklahoma Attorney General Drew Edmondson, who requested the injunction in November, said the state’s case against litter spreading isn’t ruined without Harwood’s research.
“We have to prove the problem comes from poultry,” Edmondson said. “We’ve got several ways to do that.”
Edmondson, who filed a lawsuit against eight poultry companies with operations in Arkansas in 2005, contends poultry litter threatens human health and that it should be considered solid waste under the Resource Conservation and Recovery Act of 1976.
SOURCE TRACKING Harwood, a biology professor at the University of South Florida, testified Feb. 21 that she used microbial source tracking to find a “poultry biomarker.” She told Judge Gregory Frizzell that bacteria-laden manure from chickens and turkeys is leaching from farm fields into nearby ditches, water wells, creeks, rivers and Lake Tenkiller. The 99-mile Illinois River starts in Arkansas and drains into Lake Tenkiller near Tahlequah, Okla.
The poultry companies intend to call their own microbial source tracking expert — Sam Myoda of the Institute of Environmental Health Laboratories and Consulting Group in Lake Forest Park, Wash. — to testify this week.
Myoda questioned the validity of Harwood’s research in an affidavit filed with the federal court on Feb. 12.
Harwood’s work hasn’t been reviewed by her peers, and it shouldn’t be used for regulatory actions or to draw conclusions about the source of bacteria in watersheds such as the Illinois River, Myoda wrote in the affidavit.
Neither Myoda nor Harwood returned telephone calls seeking comment.
On Feb. 21, attorneys for the poultry companies described Harwood’s testimony as cutting edge but also unproven and unreliable.
Microbial source tracking can be used to determine the source of fecal bacteria. It’s done by looking at the DNA of host-specific bacteria found in one animal species. For example, the genetic makeup of the fecal bacteria from a cow is distinct from what’s found in the manure of chickens, dogs or other animals. Figuring out the source of a contaminant is important in determining how best to reduce the amount of bacteria in the environment, said Don Stoeckel, a U. S. Geological Survey research hydrologist at the Ohio Water Science Center in Columbus. If the source of contamination is human waste, for example, fixing septic tanks would be an important step in improving water quality, Stoeckel said. “There’s no one microbial source tracking methodology,” Stoeckel said. “It’s a family of tools. It’s a developing thing. “ We learn from failures in science. We get our results and then try to make it work better.”
‘PROOF OR EVIDENCE’ Microbial source tracking has been around for a little more than a decade.
Mansour Samadpour, Myoda’s boss who’s also assisted the poultry companies in their fight against the preliminary injunction, was one of the earliest tracking researchers, Stoeckel said.
Samadpour studied strains of E. coli to identify the sources of contamination in apple juice in 1996, and later modified that research and took it outdoors to determine what polluted three beaches on a Washington lake.
Similar tracking has been performed nationwide.
In California, surfers and swimmers got sick in the Santa Barbara suburb of Hope Ranch. When the problem persisted after homeowners’ septic tanks were repaired and horse manure was kept out of a creek that led to a beach, four graduate students and a professor at the University of California, Santa Barbara, used microbial source tracking in 2006 in a bid to figure out what caused the sickness.
“We think the horse waste was probably influencing the water, but we didn’t find the horse marker as evidence,” said Patricia Holden, an environmental microbiology professor at the University of California, Santa Barbara.
In New Mexico, a three-year study using microbial source tracking showed 71 percent of fecal bacteria in the Rio Grande at Albuquerque stemmed from birds, dogs and humans, according to the Albuquerque Journal.
In the Portage River watershed that drains into Lake Erie in northwest Ohio, researchers from Bowling Green State University, the U. S. Geological Survey and a county health department are using the science in a $ 30, 000 pilot study to evaluate how large dairies, septic tanks and animals impact the river’s water quality.
Two dairies have been built in the watershed and three more are planned, said Christopher Kephart, a geological survey hydrologist.
“We’re not there to point any fingers,” Kephart said. “We’ll provide the data to the county health department. They can make their regulatory decisions, but this project is small, so it won’t have any regulatory influence.”
The U. S. Environmental Protection Agency offered guidance about the use of microbial source tracking in 2005. States often use it to figure out how to improve water impaired by bacteria, said Jane Watson, chief of the EPA’s ecosystems protection branch in Dallas.
“There are many different methods to doing these tests,” Watson said. “It depends on what the question is and how complex the situation is as to which of the methods you pick.”
Edmondson, the attorney general, said he sees Harwood’s work as part of a chain of evidence, but he’s got another chain that runs parallel to it.
Roger Olsen, an environmental consultant with the consulting firm Camp Dresser & McKee in Cambridge, Mass., testified on Feb. 22 that he’s used 25 chemical components in poultry manure to track its “signature” from fields to waterways.
“Dr. Olsen tipped us off about Harwood’s work,” Edmondson said. “It was his suggestion that we follow up with her as gravy. It’s not that she was needed. It was just added weight with a different approach.”
Stoeckel, who’s not involved in the Oklahoma case, said there are 20 people who frequently do microbial source tracking in the U. S., including Harwood, Myoda and Samadpour, and another 100 people who “dabble” in it, Stoeckel said.
“On a good day, microbial source tracking can tell you the host and where some of the contamination came from, but saying it came from this property or that property, that’s not an outcome of microbial source tracking.
“ Our legal guys trip over whether this is proof or evidence,” Stoeckel said. “I see it as evidence.”
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