AS THE POPULATION and the national economy grow, the amount of environmental pollution inexorably grows with them. Air, land and water, on the other hand, are finite and don't grow, so their capacity to absorb pollution cannot increase. On top of this growth in pollution, there are several other reasons why the price of environmental cleanup will keep increasing. Earlier control efforts attacked the most obvious pollutants, which were often the easiest to clean up. And enormous improvements in the technology for measuring minute amounts of substances means that contaminants that were undetectable a few years ago may now require regulation.

It is also becoming apparent that standards set separately for each pollution source often afford dinadequate protection.Lead pollution, for example, can come from paint and auto emissions and through water. While each separate standard is set to achieve a safe level, an individual may be exposed to all three sources. Even harder to deal with than such cumulative effects are synergistic ones, in which several pollutants interact, posing a danger greater than the sum of their individual effects. Current regulatory schemes have not begun to cope with these types of challenges.

Is there, then, any alternative for the future other than a dirtier environment, on the one hand, or steadily rising costs, more and more government regulators and paper work, and industry resistance on the other? The Environmental Protection Agency believes there is. Salvation, says EPA, lies in finding ways to make industry the government's eager partner in control efforts, rather than its adversary, by appealing to the profit motive. In effect, EPA wants to create a free market in the pollution-control business.

The greatest need is to stimulate innovation in pollution-control technologies. Most of the existing means are primitive and expensive. Though there are enormous opportunies for improvement, most current research is being done by the government. Industry's interest has been weak because detailed government regulations spelling out precisely how much pollution is to be controlled remove any incentive for management or plant engineers to find better, cheaper ways. A large steel mill, oil refinery or chemical plant may have to meet 40 or 50 different pollution standards and therefore creates an immense regulatory burden for the company and the government. EPA is proposing that, instead, such a plant be imagined to exist within a bubble with a single opening. The pollution that emerges must be no greater than the total allowed under the many individual standards, but the company is free to use any methods it can, at the least cost, to achieve the overall result.

Expanding the bubble concept from plants to regions, EPA is testing another new policy it calls "offsets." Under that policy, if a company wants to build a plant in an area that is already at or above its allowed pollution limit, the company is allowed to persuade (generally with cash) other industries in the area to reduce their emissions by the amount the new plant would add. Both these new approaches could eventually be expanded to allow companies to earn "pollution credits" that could be banked for later use or sold to other companies. Someday there might be nationwide brokerage firms buying and selling pollution credits.

EPA's proposals could turn out to create more difficulties than they solve, but they deserve a fair and vigorous trial. Industry, which has loudly complained about the cost of environmental controls and the loss of innovation in American industry, ought to be a good deal more interested in these new approaches than (with some notable exceptions) it has been. Regardless of the final outcome, EPA deserves congratulations for that government rarity -- a creative and practical new idea.