Expanding on a program launched in the Great Lakes, Bay Program participants are moving to eliminate “mixing zones” for chemical discharges in the watershed.

 he measure — heavily pushed by environmental groups last year — has been added to the draft Chesapeake 2000 Agreement, which is expected to be signed shortly.

Details of the mixing zone phase-out are expected to be spelled out in a new Bay Program “Basinwide Toxics Reduction and Prevention Strategy” to be released later this year. Although toxics are but a small part of the Chesapeake 2000 Agreement, completing a Bay toxics strategy is actually the first commitment due under the agreement.

The mixing zone language strengthens the toxics portion of the agreement, which had been criticized during the public comment process for lacking specifics.

Mixing zones are an area beyond the end of a discharge pipe where pollutants are allowed to exceed water quality criteria. By mixing with water in a river, lake or stream, the mixing zone allows contaminants to become diluted enough to meet water quality standards outside the mixing zone.

Saying that amounts to treating pollution by dilution, a dozen environmental groups last fall called on the Bay Program to phase out mixing zones for chemicals which persist in the environment, potentially building up in sediments, or bioaccumulating in the food chain. They argued that such chemicals pose a threat, even in small quantities. Their request was spurred by a similar program in the Great Lakes.

The Bay Program’s goal would seek to eliminate mixing zones through voluntary pollution prevention efforts by 2010. Priority would be given to areas considered impacted or threatened by chemical pollution, including three Bay Program “regions of concern” — the Anacostia and Elizabeth Rivers, and Baltimore Harbor — where chemical contamination has shown clear impacts.

“We’re very pleased with the language,” said Kim Coble, of the Chesapeake Bay Foundation, one of the groups that called for a mixing zone phase-out. “It’s right in line with what we suggested.”

yhe phase-out is part of a broader “zero release” goal for air and water discharges that the draft agreement emphasized for the new toxics strategy. Although the zero release goal has no deadline, it clarifies the Bay Program’s existing goal of a “toxics-free” Bay.

Besides striving for a zero release of chemical contaminants, the draft Chesapeake 2000 agreement directs the upcoming toxics strategy to go beyond focusing on traditional point sources of pollution — such as discharge pipes — and to address toxic pollution stemming from air pollution and runoff, such as stormwater systems.

A draft of the new toxics strategy is expected to be released this summer. In general, it is designed to go further than existing regulatory programs by reducing chemical contaminants through pollution prevention programs and other voluntary means.

“We’re trying to lay out voluntary steps we can take to stay ahead of the regulatory process,” said Kelly Eisenman, toxics coordinator for the EPA’s Bay Program Office.

The strategy will contain a series of specific recommendations that originated during 13 meetings with stakeholders — everyone from business leaders to farmers to local government officials to environmentalists — in the last year. More than 300 people were involved.

“They’re telling us what they can do,” Eisenman said. In fact, she said, the zero-release goal was a suggestion that came from industry representatives. “You never know what an industry can do until you put the challenge in front of them. We feel that the zero release goal can help drive new technologies.”

The final toxics strategy is expected to lay out a number of quantifiable steps, in addition to the mixing zone phase-out, that will move toward zero release.

One potential goal is reducing the amount of toxics released into the water, air or land — as measured by the EPA’s Toxics Release Inventory — 10 percent by 2010, from 1998 levels. Federal facilities would be asked to make a 40 percent reduction from 2001 releases by 2006.

The strategy is likely to call for a dramatic expansion in the number of businesses, particularly small businesses, that participate in the Bay Program’s voluntary “Businesses for the Bay” pollution prevention initiative.

A goal under consideration would call for those businesses to either cut the use of, or recycle, a specific amount of chemical contaminants from a 1999 baseline.

Another potential goal would be to set a deadline to clean up all areas with fish and shellfish consumption bans in the Bay and its watershed. Right now, 21 areas have fish consumption advisories.

Less clear at this point are potential new directions the toxics strategy might take.

In the stakeholder forums, many advocated the reduction of contaminants in stormwater runoff, which are the main sources of toxics pollution in some areas. Activities could include pilot programs to demonstrate potential control techniques.

“We have point sources now stepping up to the plate,” Eisenman said. “They have set up some ambitious and progressive goals for themselves. We want to go beyond that and look at nonpoint sources.”

In the past, Bay Program toxics programs have been aimed at protecting aquatic life. The new strategy may call for ensuring that there are also no impacts on aquatic-dependent wildlife, such as waterfowl.

The new strategy may also address growing concerns about chemical contamination from large-scale animal feeding operations. Studies around the country have found high levels of chemical contamination, as well high levels of animal hormones, in waterways near such facilities.

A draft of the strategy is expected by early summer, to be followed by a stakeholder review. The strategy is to be adopted by the Executive Council this fall.

The draft strategy is expected to be completed by early July and will be available on the Bay Program’s web site: www.chesapeakebay.net