Somebody misread the EPA directive about the use of an additive in reformulated gasoline. It is supposed to go in the gas tank, but keeps getting put in Maine’s drinking-water supplies. The problem, however, is larger than simply finding this unpleasant tasting, smelly toxin where it does not belong.

Methyl tertiary-butyl ether, MtBE, was added to gasoline back in the late 1970s when lead was taken out. More of it was added to replace benzene in recent years because it promotes more complete burning of gasoline, reducing levels of carbon monoxide and ozone. Regions, including Maine’s seven southern counties, trying to meet Clean Air Act requirements use this mixture, commonly called reformulated gas (RFG), to satisfy Environmental Protection Agency mandates.

The level of hazardous volatile organic compounds (VOCs) in Maine’s air has fallen consistently since the introduction of gas containing MtBE to the Northeast, although weather also is a major reason for this. VOCs, in the presence of another pollutant, nitrogen oxides, form ozone, which reduces lung capacity, causes chest pain, nausea, throat irritation and can aggravate bronchitis and asthma. While a lot of VOCs are produced in nature, air-monitoring tests in Maine’s more populated regions show that during peak readings of VOCs, manmade sources are the primary culprits. Reducing VOCs allows residents to breathe easier.

But users expected to drive with RFG, not have it piped into their kitchen sinks. North Windham currently is trying to find the source of MtBE in its drinking water. So is Whitefield. Standish may have a problem, too. Other communities have found the source of the contamination and have undertaken expensive remediation efforts. Gov. Angus King last week ordered statewide testing of public water supplies to determine how far the potential carcinogen has spread. Critics of MtBE have used the contamination to point out the danger of the additive and try to prevent its continued use.

The EPA doesn’t know what size dose of MtBE begins to do serious damage to people, and Maine should resolve not to be the state that finds out. But it would be a mistake to focus only on the additive and ignore the broader implications of its presence in groundwater.

MtBE, a colorless liquid, is highly water-soluable, allowing it to enter and be detected in a water supply faster than other components of gasoline. But the key is that MtBE doesn’t show up unless the rest of the gasoline compound is close behind — it is the proverbial canary in the mine. And unlike its uncertainty over MtBE, the EPA knows that injesting gasoline even in small quantities is harmful.

A couple of years ago, the Legislature considered a bill called the well head protection act, which limited development around drinking water wells to keep pollutants away from these vital supplies. It never made it out of committee because lawmakers were unhappy about it potential costs. In a subsequent session a voluntary protection act passed, which has helped somewhat but Gov. King’s testing order will spend $100,000 to find out how much Maine is about to pay, in part because it saved a few dollars several years ago.

But while the state is busy with its water tests for MtBE, the public needs to keep in mind that the problem is not that Maine and many other states have used this pollution-cutting additive in the gas mix, it’s that far too much gasoline is ending up where it doesn’t belong — in drinking water.