If it is precise to describe the American people - that tangled collective - as having made a commitrnent to achieve any single public objective, it may be said fairly that they have resolved to clean up the waters of the nation and rid them of pollution. The commitment can be substantiated, not only by a quick reading of presidential pronouncements and congressional acts and appropriations, but more emphatically by the volume of outraged condemnation of polluted waters that has appeared in the popular press, and by the astonishing total of debt approved each year by local voters for sewage collection and treatment and watersupply facilities.