The consolidation question, in Pittsburgh and elsewhere, touches on a variety of issues: level of taxes, quality of service and redundancy in government. Add to that list how a region organizes and operates sewerage systems.

A study released Thursday by the National Academy of Sciences and sponsored by the Allegheny Conference on Community Development faulted 11 counties in southwestern Pennsylvania for having too many small, autonomous municipal treatment systems. The independence that so many towns and boroughs value is a factor that has prevented the region from taking care of an expensive health hazard: the overflow of untreated sewage into the water supply.

In other words, if Pittsburgh is to end this malodorous, bacteria-filled threat, small is not beautiful.

The fact that the region has a water quality problem is not new. "Investing in Clean Water," a 2002 study by a local group headed by Carnegie Mellon President Jared Cohon, described the situation in great detail, and the Allegheny Conference has been trying to organize an effective community response.

What is new is the academy study's call for either a consolidated government or the coordinated management of treatment systems to approach the problem from a regional basis. The 11-county area has almost 600 municipalities and nearly 500 water and sewerage providers, all of which are required by law to meet federal health standards.

The cost of compliance -- rebuilding water, sewer and septic systems so that routine rainfalls do not send raw waste into rivers and streams -- could be as much as $10 billion. That would be a monumental undertaking, but one whose price tag could be cut by joint effort and consolidation.

Money, of course, will be a key ingredient in addressing this health hazard, but leadership is just as necessary. It's time for elected officials and municipal-authority managers to join with the academics and business types in a plan to wipe 19th-century conditions from our 21st-century landscape.