Congress has moved to halt the EPA’s efforts to require enforceable new water cleanup strategies for polluted lakes, rivers, streams and estuaries across the nation.

Language attached to an $11 billion emergency spending bill prohibits the agency from implementing its proposed new rules to guide development of cleanup plans known as Total Maximum Daily Loads before October 2001. The new rules, proposed last fall, have drawn widespread opposition.

The administration earlier had prevented several other provisions it considered harmful to the environment from being added to the bill, which won final passage on June 30, but a White House spokeswoman said the TMDL language was added “late in the game without warning.”

“The EPA regards this as another anti-environmental assault by the Congressional leadership against the administration’s efforts to bring cleaner, healthier water to all Americans,” said EPA spokesman Dave Cohen.

Nonetheless, President Clinton was expected to sign the measure, which would provide money for the Pentagon, drug fighting in Colombia, disaster relief and other purposes.

The action in Congress came just two days after the EPA issued its most recent assessment of the nation’s waterways. Drawing on 1998 data, the report found that 40 percent of the nation’s waterways are too polluted for fishing and swimming — a figure essentially consistent with findings from the past decade.

Leading causes of water quality problems, according to the report, were runoff from agricultural lands and urban areas. The chief pollutants, it said, were sediment, bacteria, the nutrients nitrogen and phosphorus, and metals.

Overall, the report said more than 290,000 miles of 840,000 miles of assessed rivers and streams do not meet water quality standards, as well as nearly half of all lakes, reservoirs and ponds.

Supporters see TMDLs as an important tool in forcing the cleanup of waterbodies that remain polluted nearly three decades after passage of the Clean Water Act.

TMDLs are cleanup plans that calculate the maximum amount of pollution that a water body can receive and still attain its water quality standard. That pollution level is then allocated among various sources so the standards can be met.

The 1972 Clean Water Act required TMDLs for waterways that failed to attain standards after basic pollution control technologies were in place for factories and other dischargers. But the TMDL requirement has only been enforced in recent years as a result of suits by environmental groups.

An estimated 40,000 TMDLs are needed nationwide, including one for the Bay unless it is cleaned up by a court-set deadline of 2011.

Existing TMDL rules are vague on key points, though, such as how long states have to develop the plans, and whether they need to be implemented.

The EPA’s proposed new rules would have set a 15-year time frame for writing TMDLs. As part of the plans, the agency also would require that states submit implementation plans, and provide “reasonable assurance” that the plans would be carried out.

The rule drew widespread opposition, especially from farmers and loggers who feared they would come under increased scrutiny, as well as from states who said the new rules would be too costly.

“There is overwhelming opposition across the country to the EPA’s proposals,” said Rep. Larry Combest, R-TX, who chairs the House Agriculture Committee. One Agriculture Department official told a House subcommittee in June that TMDLs had become the “new four-letter word in rural America.”

Lawsuits, though, have forced deadlines on the states that are tighter than what the EPA had proposed in its new rules.

If the new rules are not implemented, the old TMDL rules will stay in effect.

The new EPA report, “National Water Quality Inventory: 1998 Report to Congress,” is available on the internet at: www.epa.gov/ow.