POLLSTER LOU HARRIS testified before Congress recently concerning public attitudes on proposed changes in the Clean Air Act and environmental protection in general. He summarized his findings as showing that the "desire on the part of the American people to battle pollution is one of the most overwhelming and clearest we have ever recorded in our 25 years of surveying public opinion in this country."

Skeptical congressmen wondered why the results were so different from public attitudes toward other types of federal regulation and whether Mr. Harris' questions had ignored the costs of environmental protection. Mr. Harris acknowledged the differences, but insisted that a healthful environment "happens to be one of the sacred cows of the American people" and "that is the message that comes out of this as clear-cut as anything I have ever seen in my professional career."

Other recent polls support the tenor of the Harris results. But despite the public support, the Environmental Protection Agency, the federal body charged with protecting or regulating the condition of air, water, noise, radiation, chemicals, pesticides and other items of environmental concern, is in a state of near crisis. Recently leaked documents suggested that EPA Administrator Anne Gorsuch was planning to propose a 20 percent cut for her agency's 1983 budget. This was over and above the two 12 percent cuts proposed for this year, and would be the starting point for whatever cuts might be made by the Office of Management and Budget. The same documents showed a proposed cut in personnel of 31 percent, in addition to the 6 percent annual attrition rate. Together, the actual and proposed measures would cut the EPA in half by 1984 while its workload swells with the addition of new responsibilities for cleaning up chemical waste.

As Congress considers the budget proposals, Mrs. Gorsuch is taking other steps with similar impact. EPA's enforcement arm has been tied. Violations of EPA regulations reported to the Justice Department for prosecution are a fraction of the number reported in earlier years. Official spokesmen say that Mrs. Gorsuch prefers to rely on voluntary compliance. But effective enforcement, with the demonstrated willingness to go to court on a few cases, is what it takes to make voluntary compliance work in the tens of thousands of other cases.

All this is having the predictable effect, though surprisingly quickly for an agency known for its unusual spirit. Employees are reported to be voluntarily leaving the agency at the rate of 1 percent per month. These employees, who presumably have found jobs elsewhere, are likely to be the agency's best and brightest. No institution can sustain that rate of loss and the crumbling morale now apparent at EPA and continue to function for very long.