The Butler Area Sewer Authority is correct in deciding to explore all billing options for meeting its costly future obligations.

The authority is receiving tough scrutiny from the state Department of Environmental Protection over the issue of removing stormwater infiltration from the BASA system.

Eliminating that infiltration, which contributes to sewage overflows during periods of heavy rain, will require major improvements to the system. Those improvements might include expansion of the existing sewage treatment plant or building a new one.

The work that lies ahead will involve millions of dollars, and the cost of all of that work will be borne by BASA customers through their regular sewage bills or surcharges.

In connection with its money needs, BASA has opted for a study that will deal in part with the issue of using metered billing instead of the current flat-rate billing.

Prior to opting for the study, the authority had been poised to approve phased-in rate increases.

Metered billing, if it were initiated, would be tied to water usage, and that could result in significantly higher bills for some authority customers, especially for larger families or others who, for whatever reason, use large quantities of water.

The study also presumably will deal with some of the complexities involved in trying to achieve overall billing fairness, such as how much to bill people who have BASA sanitary sewer service but who are served by non-metered well water.

Meanwhile, it must be acknowledged that not everyone is contributing stormwater infiltration to the BASAsystem. And, some residents who already are paying surchanges stemming from sewer line extensions in their municipalities about 1980 feel they shouldn't have to pay extra for the extensive sewer system work needed in the city.

Already evolving is the idea that surcharges should be imposed on city customers for the work being done there.

Other issues and complex scenarios no doubt will surface during the study and during actual consideration of what billing system would best serve BASA and its customers in the future.

The impact on all categories of customers must remain a central concern for BASA officials. BASA must remain committed to keeping its rates as low as possible.

Based on what some places currently are paying, BASA's rates are reasonable. However, the potential for that to change significantly, based upon the pressure being exerted by the DEP, is quite high.

It is reasonable to conclude that the days are numbered for low-cost sanitary sewer service in BASA municipalities. How much the rate increases will be and when they will be implemented will remain the big questions in coming months.

For now, about the only certainty is that the study will take six to eight months to complete.

This is not a happy time for BASA, and the study, a troubling prospect from customers' vantage point, will remain a source of considerable anxiety as customers await the authority's rate decisions.