The residents of Maine expect and depend on clean water. For our fishing industry, outdoor recreation, tourism and safe drinking water, we all need clean streams, rivers, lakes, ponds and coastal waters.

It was only natural that Maine’s Sen. Edmund S. Muskie was a key leader in the passage of the 1972 Clean Water Act, which provided comprehensive protections for all of our nation’s important waters. Now it is time for Sens. Olympia Snowe and Susan Collins to continue Maine’s long, proud and courageous tradition of standing up for clean water.

For three decades, government agencies and their employees, charged with enforcing the Clean Water Act, have worked hard to clean up and protect our waters with a comprehensive view, realizing that small headwater streams and wetlands are the lifeblood for our bigger downstream rivers, lakes and the ocean.

However, in the last decade, two unfortunate Supreme Court decisions have thrown basic implementation and enforcement of the Clean Water Act into turmoil. The result of these decisions (Rapanos in 2006 and SWANCC in 2001) is that basic federal pollution protections for important headwater streams, wetlands and so-called “isolated waters” such as bogs and fens now have to be hashed out on a case-by-case basis. The result has been a troubling drop in pollution enforcement actions, increased confusion, permitting delays and a weakening of clean water protections in Maine and throughout our nation.

The threat to our nation’s — and to Maine’s — water supply is alarming. Nationwide, 20 million acres of wetlands and the 60 percent of our streams — those that flow intermittently — are at risk of losing Clean Water Act safeguards. In Maine alone, the health of all of our big rivers and coastal waters is at risk, because their health depends on clean upstream headwaters and nearly 300,000 acres of “isolated” wetlands.

Moreover, according to the Environmental Protection Agency, more than 450,000 Mainers receive some of their drinking water from small streams, and those waters also are now in jeopardy. The Maine Department of Environmental Protection previously stated that “much of the progress we have made through water quality protection efforts [under the Clean Water Act] could be put at risk should federal protection of these resources be reduced.”

The good news is that the problem can be fixed. Two Supreme Court justices, hunters, anglers and numerous environmental and industry groups have called for a badly needed rule-making process required to establish explicit guidelines. The Obama administration has responded by working to finalize guidelines that clarify the scope of the Clean Water Act as it applies to rivers, lakes, marshes, streams and other waters and by implementing a rule-making process to develop clear criteria to guide future agency decisions.

Rather than let the administration do its job and fix this mess, there is a sneak attack by some in Congress to stop the administration’s efforts. A spending bill rider, expected to be offered by Sens. John Barrasso, R-Wyo., and Dean Heller, R-Nev., would, in effect, say that there is no need to clarify what waters the Clean Water Act protects. Other similar riders may be offered in coming weeks. If such a rider passes, pollution enforcement will remain limited, water quality will continue to be threatened and everyone will lose except, perhaps for a while, the polluters — until the problems of unhealthy water catches up with them too.

It is time for the confusion to be put behind us and for the administration to be allowed to clearly restate the principle that the Clean Water Act applies to all of our nation’s waters — large and small. All of our waters are interconnected and are integral to our well-being. Fish, wildlife and people all rely on and deserve clean drinking water, healthy places to swim and a safe food supply.

That is why I urge Sens. Snowe and Collins to stop the assault on our nation’s clean water protections and oppose any dirty water provision that is presented, including the Barrasso-Heller Amendment to the Fiscal 2012 Energy and Water Appropriations bill (H. R. 2354).

Lois Winter of Portland is a conservation biologist who has worked for more than three decades in Maine.