Members of Congress continued to express skepticism in March over whether the EPA has the legal authority to impose its proposed new rules for cleaning up the nation’s polluted waterways.

The controversy is swirling around the EPA’s planned rules to guide the development of future Total Maximum Daily Loads — cleanup plans for waterbodies that still fail to meet water quality standards 28 years after the passage of the Clean Water Act.

Through mid-March, the rules had been the subject of five mostly hostile hearings, and more were planned. In addition, the TMDL rules drew questioning of EPA Administrator Carol Browner during appropriations hearings for the agency.

“In my seven years in Congress, I have never seen one proposal draw this level of attention and scrutiny by committees with different jurisdictions,” said Sen. Michael Crapo, R-ID, chair of one of the hearings.

Legislation has been introduced to block some aspects of the rules, and some lawmakers indicated they would seek to delay the EPA’s planned June 30 release date for the final regulations.

A hot issue is whether the EPA is seeking to regulate runoff, also known as nonpoint source pollution, something critics say it has no clear authority to do under the Clean Water Act. Browner said at an appropriations hearing that the agency is not planning to regulate runoff. “The Clean Water Act does not allow the EPA to require a permit for nonpoint pollution,” Browner said. “Period.”

A TMDL is a calculation of how much pollution a given area of water can receive and still meet its water quality goal with a margin of safety. About 40,000 TMDLs are required nationwide, including hundreds in each of the Bay states. In addition, the Bay itself is listed as impaired and, under a court agreement issued last year, it will need a TMDL unless it is cleaned up before 2011.

The TMDL requirement had been on the books since 1972, but was largely ignored until recent years when environmental groups began winning suits against the EPA for not requiring the cleanup plans.

But existing TMDL rules are vague. Details such as how long it would take to develop a TMDL, or even whether it had to be implemented, were never spelled out. It was also unclear what to do when most of the pollution came from unregulated runoff, such as farms.

To clarify the issue, the EPA issued new rules last August and took public comments — getting more than 30,000 — through Jan. 20. The new rules require states to write TMDLs for polluted waters, along with implementation schedules, within 15 years. In addition, states have to provide “reasonable assurance” that the pollution reductions will be achieved — enough money to support voluntary runoff control programs or new regulations if needed.

Under the proposed rules, if states fail to complete TMDLs, or if their plans are not adequate, the EPA can take over the job and designate certain operations such as animal feedlots and forestry activities as point sources and require them to have discharge permits.

But critics say the rules are only a thinly veiled attempt by the EPA to regulate nonpoint source pollution — either directly, or by requiring states to do so. “The EPA has proposed to change the definition of what a nonpoint source is, subjecting private land activities such as traditional agriculture and forestry activities to federal ... permits,” Crapo said.

That concern was also raised by a senior USDA official in a letter sent to the EPA last fall questioning the agency’s legal authority to regulate farm runoff.

Agriculture Secretary Dan Glickman, testifying before the Senate Agriculture Committee, disavowed the letter. But Glick man said he still had concerns about the plan, including the lack of a comprehensive cost estimate. The rules are “very complex and would present a challenge to any expert on the issue,” Glickman told the committee.

Browner, who appeared before the committee alongside Glickman, emphasized that it would be up to each state to decide how to meet the reductions in pollutants required by their plans. She said the agency’s proposal was a “very, very sensible way to do the final work to ensure clean water for everyone in this country.”

The proposal has been sharply attacked by the logging industry — which accounted for half of the comments received on the proposal — because it would allow the EPA, under certain circumstances, to regulate forestry activities as a point source and require a discharge permit.

Robert Adler, a law professor from the University of Utah, testified that the EPA has always had the right to regulate forestry activities. In the past, he said, those activities had been exempted by the EPA’s own regulations — not by law. “What the EPA proposes to do now is simply to modify those regulatory exemptions,” Adler said.

Adler also said the agency was within the bounds of the Clean Water Act by requiring nonpoint sources to be dealt with under the TMDL program. He argued that the act first required a set of technology-based controls for point sources, then required TMDL development for places where that did not fully clean up the water. He called it “illogical” to conclude Congress wrote that intending nonpoint sources to be ignored, especially as congressional reports dealing with the act’s development cite runoff as a major problem.

Besides farmers and loggers, the rules have drawn fire from state officials, who say the program would be hugely costly to carry out, and from cities who fear the rules would force development into the countryside to avoid stricter pollution controls than would be needed for polluted urban waters needing TMDLs.

Meanwhile, Sen. Blanche Lambert Lincoln, D-AK, has introduced legislation that would prohibit the EPA from regulating runoff from private logging operations. She said it should be left up to states to decide whether to regulate such pollution.