ONE HUNDRED FIFTY YEARS ago Maine's Penobscot River supported a flourishing salmon industry. Then came industrialization and pollution and the salmon disappeared. In the late 1960s, efforts began to clean up the river. Today people are said to be catching 20-pound salmon during their lunch hours in downtown Bangor, the catch is growing yearly -- and that is evidently not just a fish story.

At the other end of the country, a potatoe-processing plant was dumping its waste and severely polluting the Boise and Snake Rivers. Under the pressue of state and federal deadlines, the company decided to treat the waste and then use it to irrigate and fertilize crop land. This had been done before, but, with an additional creative twist, the plant engineers preserved the waste's heat. The warm sprayed wastes lengthened Idaho's short growing season to 10 months and almost doubled the crop yield on the sprayed land.

General Motors wanted to build new plants in Oklahoma City and Shreveport, though neither city met air quality standards. Under the law, additional pollution could not be added to the unhealthful levels already present. Using a new "offsets" policy developed by EPA, ways were found to control pollution from local crude oil storage tanks -- even more pollution, it turned out, than the new plants would produce. The plants, each employing several thousand workers, have now been built.

These and a couple of hundred other success stories made up a new report from the Environmental Protection Agency entitled "National Accomplishments in Pollution Control." It makes no pretense of being an accurate survey of the failure and success rate in environmental regulation, or of trying to measure costs and benefits. But it tells an important story nontheless of what evnironmental cleanup can mean when it works -- to local economies, to people's health and to the quality of life in every corner of the country.

Most of the success stories in this report, of course, are stories of progress, not of goals achieved. Though the country's air is demonstrably cleaner and healthier than it was a decade ago, for example, there are still eight major metropolitan areas where the air ranges from "unhealthful" to "hazardous" more than 100 days a year (Washington just misses with 97 days). Nor does this report record the failures: where the needed new technologies have not been found, where government agencies have succeeded only in nit-picking a problem to death, where needed programs have languished for years in the courts, or where environments and biological systems seem to have been abused beyond hope of repair.

Finally, as the report points out, established programs deal largely with the most flagrant problems, which are generally the easiest to fix. Newer items on the environnmental agenda, such as acid rain or contamination and overuse of ground water, are likely to be tougher.Still, it's good to be reminded that efforts to protect our environment can sometimes work spectacularly well.