The permit faced criticism from both directions at a public hearing called by the EPA and held Monday at the Agassiz (formerly Baldwin) School. The EPA and DEP say the electrical plant is the largest industrial discharger on the Charles River, and they are concerned with its effect on water quality and the fish population. The plant, which is operating in bankruptcy, claims the permit is too strict, and the plant doesn't have the resources to implement it.

The plant's cooling system takes water from the Charles and discharges the heated water back into the river. The permit allows the plant to use an average of 70 million gallons a day and the discharged water can reach 105 degrees. According to the EPA, these standards can cause a 400 percent temperature increase in various spots on the river, harming aquatic life.

Under increased regulations, Mirant Corp. would have to monitor and limit excessive discharge temperatures and produce barrier nets over water intake structures to reduce the number of trapped fish. Mirant said these proposed regulations are too strict. Leslie Alden, the company's senior environmental engineer, said there is no evidence that the plant's discharge is harming water quality and fish populations. "Doing what's right for the river means doing what's reasonable," said Alden.

Environmentalists argue that the discharge can harm the river. "The ecology of this river is stressed," said John Crawford, a marine scientist at the Conservation Law Foundation. "You can't predict or analyze the effect on something when you increase the stress."

Mirant agrees with the poor quality of the river, but does not feel it is the only company to blame.

"We are not suggesting that there are no problems with Charles River water quality," Alden said. "But it's equally clear that those problems have many causes - the sewer overflows, the stormwater run-off issues, contaminated sediments from other industries, and stagnation due to the operations of the dams and locks - all of which are unrelated to Kendall's cooling water discharge."

As a result of the lack of evidence, she said that the company shouldn't have to follow increased regulations when it doesn't have the resources to do so.

According to the company's Web site, on July 14, 2003, Mirant filed for protection under Chapter 11 of the federal Bankruptcy Code, which allows the company to operate while restructuring its debt under court protection. Alden said Mirant is willing to monitor the effects of its discharge, but not at the permit's standards.