A coalition of conservation and environmental groups is warning that up to a third of Mainers could be at risk of drinking polluted tapwater, unless urgent action is taken to amend federal legislation. State officials though, say there's no need to panic.

The groups issuing the warning cited a recent study by the Environmental Protection Agency. The study, they claim, suggests that at least 452 thousand Maine residents could be in danger: that's because they're among the 117 million Americans who drink water from so-called "non-navigable bodies of water" such as small streams.

"These are the backbone of our water systems, these smaller intermittently flowing streams yet we have a tendency to take them for granted," said Jan Goldman-Carter. She is with the National Wildlife Federation, one of the groups pushing for the Federal Clean Water Act to be effectively 'beefed up' to ensure government protection over these waterways.

"They really are source of a lot or our drinking water and while they're small and non-navigable, there are polluters and even sewage treatment systems that discharge into those small waters and if they're not covered under the clean water act, then they're vulnerable to pollution," said Jan Goldman-Carter.

The National Wildlife Federation and other groups, are concerned that two Supreme Decisions - one in 2001 and one in 2006 - threaten to dramatically narrow the scope of the 1972 Clean Water Act by excluding non-navigable bodies of water..

"We need the strict protections that have been in place for over 30- years restored," said Geoff Mullins. He represents the Theodore Roosevelt Conservation Partnership - one of the groups pushing for a legislative solution this Fall, in the form of an amendment to the Clean Water Act..

"The Supreme Court took it upon themselves through the 2 very confusing decisions that they made, to scale back those protections that were in place under the Clean Water Act, so we want Congress to now re-assert its authority  to clarify once and for all that those protections should be in statute," said Geoff Mullins.

There is, it seems, considerable momentum behind efforts to tighten up the Clean Water Act. Lisa Jackson, the head of the US Environmental Protection Agency, was among five federal agency bosses who sent a letter to Congress earlier this year calling for the legislation to be amended.

Even without new legislation however, it appears Maine residents should not worry about their drinking water being contaminated, says the man tasked with safeguarding the state's supply.

"In Maine we have great source water protection," said Roger Crouse, director of the Maine Drinking Water Program, says Maine's laws already guard against pollution of drinking water.

"Our drinking water supplies are well-protected. Whether it's a federal designation or not, a permit is required for any surface discharge into a water body and that won't change, regardless of whether there's a federal designation or not," Crouose said.

While Federal Law on this issue may be regarded by some as a little leaky, the state laws, say Crouse, are water-tight.