Liquid Waste Technology, LLC

Anaheim, Calif.---EPA made procedural flaws and scientific data were lacking when the agency created Part 503 sludge land application regulations in the early 1990s, according to academics and scientists at the Water Environment Federation's technical conference (WEFTEC) held Oct. 13-18 in Anaheim, Calif.

Despite the flaws, land application is a safe activity and poses no unacceptably high adverse health effects, scientists said.

Researchers and industry professionals are struggling with ways to combat the public perception that land application is unsafe and has even caused the deaths of people who came into contact with the materials. About 200 counties have banned the practice, Bob O'Dette, director of technical services of Synagro, told Sludge. The company distributes biosolids for land application.

But those fears are unfounded, scientists sand academics said. While nothing in life is risk-free, including land application, there are few, if any, confirmed cases of people becoming sick from the soil amendments, they said.

Some scientists took an opposing view. "You can't apply it without affecting people," said David Lewis, a research microbiologist and one of EPA's biosolids policy's sharpest critics. "You will have human health problems."

When the regulations were being developed, a lawsuit forced the agency to put them out before EPA was ready, Lewis said. As a result, a risk assessment for pathogens was never conducted, he said. At the time, EPA promised to perform the risk assessment later, but still has not followed through.

"Here is a rule where the science is not there yet," Lewis said.

"We dropped the ball on that," Terry Logan told the audience at the workshop. Logan is a former Ohio State University soil chemistry researcher who worked on the original regulations, but is now president and chief operating officer for N-Viro. There was not enough data at the time to perform a pathogen risk assessment, he said. Based on what scientists knew at the time, their position was "highly defensible."

But research was exhaustive in other areas, he said. Risk assessments were conducted on 400 chemicals and pollutants. However, a pathogen risk assessment still needs to be conducted. Despite the missing study, there is no reason to be concerned that land application poses human health problems, Logan told Sludge.

Scientists are always looking for more data to either support or put theories into doubt. Regulations should be modified to reflect gains in scientific and technological knowledge, Logan said.

"For the unresolved issues, the probability or catastrophe (in land application) is minuscule," said Herschel Elliott, an agricultural and engineering professor at Pennsylvania State University. "Of course, scientific uncertainties remain, but we are fine-tuning at this juncture."

There are pollutants in certain types of biosolids, Elliott said, but there are many benefits for plant growth. Just as penicillin causes 400 to 800 deaths a year and doctors still use it, so it is that there is a cost-benefit in land application. He called on critics to "come to the table to discuss how things can be improved."

If the regulations were developed today, they would fail a peer review, Lewis said. Many scientists' concerns were not satisfied before the regulations were issued. And some who have voiced those views have been harassed.

He recommended that EPA conduct any outstanding studies; enforce a policy prohibiting the harassment of agency scientists who voice objections to decisions made during the regulatory process; and establish a credible response team to investigate complaints about sludge exposure.

To be fair, Lewis said he thought land application is a good idea; it just needs more science to support it. When asked by a businessman if he should stop land-applying it, Lewis said the operator needed to be sensitive to complaints, follow the current regulations strictly, but still distribute it.

Source: Sludge, October 30, 2000 (www.bpinews.com), Business Publishers (301-587-6300)