LIKE THE POISON that spreads invisibly from underground toxic waste dumps into our drinking water, the various facets of the scandal surrounding the investigation of the Environmental Protection Agency (EPA) have seeped far from the source. It is these widespread consequences that have made the affair so shocking and so disturbing.

The Reagan Administration has certainly had its share of embarrassments in the past, but the EPA tempest combines in one package many grievous errors this Administration seems prone to: subverting stated duties, maliciously politicizing a supposedly nonpolitical body, and demonstrating ignorance of the practical repercussions of its actions. In White House efforts to deal with the problem as quickly and painlessly as possible (i.e., with a minimum of further embarrassment to itself), one can only hope that federal officials do not lose sight of the motivation for the whole investigation: to get the EPA back on track safeguarding our environment.

It was hard to miss the glaring resemblances in the initial stages of the congressional investigation to a scenario we have encountered before. The refusal of EPA Administrator Anne M. Burford (formerly Gorsuch) to surrender subpoenaed documents, the mysterious use of a paper-shredder to dispose of the documents in question, President Reagan's defense of Burford's obstinacy on the grounds of "executive privilege," the frantic passing-the-buck of various EPA administrators on the witness stand--all of these are too reminiscent of the Watergate hearings to read about without shivering a little.

Equally disturbing were reports that the main subject of the investigation, the agency's "Superfund"--money designated to help clean up hazardous waste dumps--had been turned into a political weapon. One particularly glaring example is the convincing charge that Superfund dollars were diverted from a project to clean up a toxic waste site in California to damage former governor Jerry Brown's 1982 Senate attempt.

The agency has furthermore demonstrated incompetence at the highest levels, both in allowing waste producers to dump the materials haphazardly in the easiest manner and at the lowest cost--which often means into a city sewer system or a municipal garbage dump--and in not pressing for legislation of better methods of waste disposal.

THE REAGAN ADMINISTRATION protest that the EPA follies are only another vehicle to attack it, soon to be filed away in the morgue of old newspaper stories next to past media scapegoats of the moment like Richard Allen and Ernest Lefevre. That may be true. The Wednesday resignation of Burford may lay this scandal to rest; the attention span of the public is short, and the media will soon latch onto another scandal. But what should not be lost amidst the political furor is the substantive concern that the EPA is--or should be--very important agency, not for political reasons but for human reasons. The government cannot deal with all future hazardous waste problems by buying out the town and moving all its inhabitants somewhere else, as it did in Times Beach, Mo.

And it is not right for states to bear the burden of this national, interstate problem, as the Massachusetts State legislature is trying in its creation of a $25 million state Superfund to clean up 50 of the worst Massachusetts hazardous waste dumps, including three of the EPA-determined worst 20.

An environmental protection agency, in function rather than just in name, is something this country needs desperately. After the political repercussions of the investigations are over--once the only public mentions of the EPA are made in car commercials mileage estimates--the problem of maintaining a habitable world for our children and their children will still exist.