THE PUBLIC, Congress and the Environmental Protection Agency want faster action on toxic dump sites. But the way things are going, Congress may not manage to renew the Superfund law before it expires next fall. In the Senate a bill has succeeded in making its way through three different committees. But the measure that will come to the floor leaves unsettled some basic questions. In the House last week, an Energy and Commerce subcommittee threw out a tough measure drafted by its chairman and adopted instead a version that environmentalists regard as too weak.

Both houses agree that the EPA should have considerably more money for cleanups where private parties can't be found to cover the entire bill. But making the fund much bigger may require departing from sole reliance on taxes closely related to the production and disposal of petrochemicals. It makes good sense to build the cost of safe handling and disposal into the final cost of the product. But if these taxes get too high, producers might try to evade them, for fear of losing out to foreign competitors. Since general revenues are already insufficient to cover other government operations, both houses are turning to the dubious alternative of creating a new kind of corporate tax.

Equally troublesome is the issue of assigning responsibility for cleanups. Current law holds out the possibility that a firm that has dumped a small quantity might be held legally responsible for cleaning up an entire site even if the firm had complied with all precautions required at the time. In fact, firms have several defenses to keep that from happening, but some companies say even the threat keeps them from entering into agreements with EPA and other firms.

Everyone agrees that voluntary settlements are better than protracted litigation. But EPA makes a good case that, while it is not its policy to pursue a single contributor for full costs, the threat of such action has been helpful to it -- and to private parties -- in encouraging recalcitrant firms to join in voluntary cleanup efforts. What is needed is assurance to firms that cooperate in approved cleanups that they will not be found liable in the future if these measures later prove insufficient.

Advocacy groups would also like to make it easier for private citizens living near dump sites to recover damages. This is a humane impulse that should be resisted. State courts already provide relief where a real connection between exposure and illness can be shown. Encouraging federal litigation is likely to divert resources from the more urgent task of cleaning up possible hazards. But making sure that communities can find out about chemical threats is sound policy that shouldn't be subordinated to company secrecy.

A final disagreement is over how much to trust EPA. Environmentalists, remembering the early disreputable days of Superfund handling by this administration, want to hold EPA to fixed cleanup priorities and schedules. But in an area where information and techniques are changing rapidly, rigid schedules are not likely to give the public the most protection for its money. EPA has made substantial progress in cleaning up its own act. It is entitled to a measure of discretion.