Bills have been introduced in both New York State legislative houses to make new advanced septic systems more affordable to homeowners. The aim is to encourage the installation of state-of-the-art systems that reduce the amount of nitrogen entering bays and ponds.

State Senator Kenneth LaValle and State Assemblyman Fred Thiele Jr, who sponsored the three-bill package, said more than 360,000 homes in Suffolk County that have inefficient cesspools and septic systems contribute to water pollution.

On the East End, the effects of nitrogen pollution is seen during the warmer spring and summer months as bodies of water are closed because of cyanobacterial blooms. Southampton Village and state health officials sent out an advisory to residents on Friday warning against recreational activities in Lake Agawam, which is afflicted by that blue-green algae. But Mr. Thiele said upgrading traditional septic systems with newer models that have advanced nitrogen treatment and removal systems can cost homeowners upward of $20,000.

“The cost of living is high on Long Island and improvements such as advanced septic systems must be affordable,” he said in a statement. “Through financial incentives such as rebates, reduced approval costs, and loan programs, it is possible to make the cost of new technology comparable to traditional septic systems, while eliminating the social cost of polluted waters which adversely affect our environment, our health, and our economy.

“We must act now to clean up our water at the lowest possible cost,” he continued.

If the first bill is approved, installing a nitrogen-reducing system will no longer need an engineer’s sign-off—as long as the system meets manufacturing guidelines, like designed for a flow of less than 1,000 gallons per day, and are on Nassau or Suffolk counties’ pre-approved lists.

The change in law is projected to shave $3,000 off the cost of the installation process for each house. Another bill will allow municipalities to establish a Septic System Replacement Loan Program, for homeowners to repay the price of the project over a maximum of 10 years on their property tax bill. The third bill will allow for the five East End towns to use Community Preservation Funds to finance those loans.

Southampton and East Hampton towns, as well as the state and county, have offered other financial incentives to homeowners to replace old septic systems in the past. New York provided Suffolk County with more than $10 million in funding from the State Water Quality Infrastructure Improvement Act for rebate incentives. East End towns also use up to 20 percent of their Community Preservation Funds for water quality improvement projects, including septic system upgrades.

“We continue to focus our efforts on keeping Long Island’s waters pristine,” Mr. LaValle said, “continued the $2.5 Billion Investment in the Clean Water Infrastructure Act of 2017; and The Center for Clean Water Technologies has our ongoing financial commitment. It’s critically important that we eliminate nitrogen from our water.”