Water quality is of paramount importance to Long Island and its sole-source aquifer. The State Legislature now appears to have recognized this.

The lawmakers — many from Long Island — listened Monday to dozens of scientists, environmentalists, elected officials and other experts testify about our region’s water problems. And there are many, chief among them nitrogen pollution, which harms shellfish and other marine life, causes red and brown tides, and helps destroy marshes and wetlands. But the problems are well known by now. The difficulty is how to solve them, and how to find the money to do that.

So we were heartened to hear a healthy exchange between lawmakers and Suffolk officials about a county proposal for a public referendum for an annual fee on water usage. That would provide funding to help thousands of homeowners replace failing cesspools and septic systems, by far the major source of nitrogen pollution in the county. The give-and-take was a constructive step forward from the controversial and failed presentation of the plan last spring.

Suffolk proposes to ask voters whether they want to pay $1 per 1,000 gallons of water used; county officials say that would raise $74 million a year. That’s a significant amount of recurring revenue that would help many of the 360,000 homeowners not connected to sewers. But placing such a referendum on the ballot requires approval by the State Legislature — the same lawmakers who held Monday’s hearing, one of two statewide.

So they pressed County Executive Steve Bellone to flesh out the plan and, referencing the budget-challenged county’s recent history, they insisted that any new money be placed in a “lockbox” where it could not be used for other purposes. Both are legitimate concerns. Suffolk should listen to the feedback, explain the details and make sure the language is precise. Process matters.

Bellone, for his part, asked lawmakers to let Suffolk residents vote on the plan to reduce nitrogen and preserve groundwater, also a reasonable request. Since this is an election year, voters should ask candidates where they stand. And if they oppose the plan, what’s their counterproposal? There may be other sensible funding ideas, but this one has promise.

advertisement | advertise on newsday

The timing of Suffolk’s push is good. Water quality has emerged as a major issue on Long Island, and the No. 1 issue on the East End, according to a poll by a local environmental group. State and local officials are working on setting maximum nitrogen levels for each Long Island watershed, Suffolk is about to certify a handful of high-tech wastewater systems for homeowners, and East End residents will vote in November on a referendum to let those five towns take millions of dollars set aside annually for land preservation and use it for projects to reduce nitrogen.

If we get this right, the payoff will be huge. Stony Brook University professor Chris Gobler told lawmakers about places where water quality has improved. Like Northport Harbor, once known for its toxic red tide. Since its sewage treatment plant was upgraded in 2013, reducing nitrogen by half, its shellfish beds have not been closed once.

That’s the outcome all of Long Island seeks. So thanks for all the words spoken Monday. But now it’s time for action. — The editorial board