A coalition of municipal leaders, politicians and environmental groups on Tuesday accused the state of short-changing sewage-treatment projects across the state.

Seventy-three communities including Ansonia, Bridgeport, Milford and Stratford need more than $2 billion for sewage-treatment-plant upgrades. But the state is committing only $20 million toward the effort this year, the Clean Water Investment Coalition said.

The new group, which includes the Connecticut Conference of Municipalities and the Connecticut Fund for the Environment, called on the Legislature to approve $70 million in Clean Water Funds for 2007.

"This stepped-up investment is essential because clean water progress has virtually ground to a halt," said Curt Johnson, program director for Connecticut Fund for the Environment, in a statement released after the coalition's Capitol news conference Tuesday morning.

"If the pathetic level of funding in the proposed budget continues, restoration of the dead zone in the Sound will continue for a quarter century and raw sewage will flow into the Connecticut River and Sound for at least another hundred years."

Failure to fund the upgrades will hamper state efforts to reduce nitrogen that the plants release into Long Island Sound and other waterways, Johnson said. Nitrogen feeds algae that can rob water of the oxygen that marine life needs to thrive.

The state had traditionally invested $40 million to $50 million annually in the Clean Water Fund, the coalition said. But in 2002, the money was used for other programs because the state faced a budget crisis, said coalition members. Last year, the Legislature and the governor agreed to a two-year state budget that included about $20 million in grants a year for clean-water projects. The state also set aside nearly $70 million for loans to cover the difference.

Dennis Schain, spokesman for the state Department of Environmental Protection, said Gov. M. Jodi Rell has put together a task force to look at ways to fund the upgrades more efficiently. "Everybody knows that there is more need than funds available," he said.

Rell's office said in a statement that the governor has announced plans to provide $208 million this year and next for Clean Water Fund projects in 26 communities.

"Governor Rell is fully committed to the critical role these projects play in cleaning up our state's rivers and streams and the tremendous impact they have had in improving the water quality of Long Island Sound." Rell's spokesman, John T. Wiltse, said.

Milford Mayor James L. Richetelli Jr. said the depletion of the Clean Water Fund has pitted communities against one another as they seek funding for their projects.

Milford needs funding for denitrification upgrade projects at its Beaver Brook and Housatonic sewage treatment plants. Although the State Bond Commission recently approved $36 million for the Housatonic project, the Beaver Brook project received a lower priority.

"We were put in a situation in the last few years where we had to fight for moneys that had been promised to us, and put us into competition with our neighbor in Stratford," said Richetelli, one of the speakers at Tuesday's news conference.

Stratford received $55 million in funding for similar upgrade projects.

Other projects awaiting funding include sewage system overhauls in Bridgeport valued at $74 million and sewage-treatment plant upgrades and other work in Ansonia valued at a total of $32 million.

State Sen. Bill Finch, D-Bridgeport, also a member of the coalition, said now is not the time for the state to back off its commitment to cleaning up its waters, which have improved greatly since the Clean Water Fund was started in 1987.

"I see osprey catching bluefish in Bridgeport's Yellow Mill Creek, whereas there was nothing living there just a few years ago," he said. "We don't want to go backwards."

Edward Crowder, who covers regional issues, can be reached at 330-6326.