What is it about the Disney's America theme park, proposed for the scenic bucolia of Virginia near Manassas, that has made it such a flash point for so many diverse interests?

A rally in Washington today will represent some 50 opponents, from the Chesapeake Bay Foundation to the American Lung Association, from transportation planners and history buffs to Virginia garden clubs, the Sierra Club and neighborhood groups.

They are unified by three key reasons, the same three often cited by real estate agents in determining a property's value: location, location and location.

Though Disney has chosen a state and county whose political leaders, rightly or wrongly, want the park on almost any terms, it is utterly in the wrong place in that state and county.

Inevitably, the opposition includes some run-of-the-mill NIMBYism (Not In My Back Yard). And the project's sheer size, close to a square mile of land for the park and nearly four more square miles for related development on Disney-owned or optioned land, guaranteed some outcry.

But it is the type of development -- rapid and immense sprawl, made inevitable by Disney's ill-chosen rural location -- that above all has turned its America into a regional and national environmental issue.

I suspect that much of the public still sees land-use decisions like sprawl development as largely local in their impact, affecting open space, agriculture and the beauty of the countryside. If Prince William County officials want to give carte blanche to Disney's request for a massive rezoning where such development never was planned (a 7-1 approval seems likely next month), isn't that their business?

If they want to forgive the multibillion-dollar corporation nearly $400,000 in zoning application fees-- the same amount Disney spent lobbying state and local officials -- isn't that a local matter?

If George Allen, Virginia's new governor, wants to subsidize Disney (whose chief executive officer made $203 million in 1993) with $160 million for sewers, roads, solid waste, fire prevention and job training -- well, isn't that Virginia's decision?

The answer is a "no" as big as the ears on that mouse.

Consider first the general impact of sprawl development, as documented in studies for the bay region and other places. Compared with development around areas where the public already has invested in infrastructure, sprawl means:

* Twice as much road building, twice as much air pollution from additional commuting, increased traffic congestion and two to four times the use of forest, farm and wetlands to house each additional person.

* Substantially lower tax yields per acre, coupled with costs for extending utilities and services that usually exceed those tax revenues.

Analyses of the project by the Chesapeake Bay Foundation and others show how these impacts are likely to play out with the bay and the Washington metro region.

New housing units surrounding the theme park, mostly in the next 20 years, will leap from about 3,000 to 10,000 and the population from 7,000 to 29,000; an additional 75,000 automobile trips per day will be generated. All this will send about 70,000 to 95,000 pounds of additional nitrogen (from septic tanks, autos and paved area runoff) flowing down streams and into Chesapeake Bay. In comparison, the whole Eastern Shore -- farms and sewage -- sends about 1 million pounds a year of

nitrogen to the bay. (Nitrogen is a prime bay pollutant that we are spending hundreds of millions of dollars to reduce by 40 percent.)

More sediment, air pollution

Similarly, the sprawl development from Disney will send 4 million to 6 million pounds of sediment toward the Chesapeake, via the Potomac drainage.

Air pollution from autos, which will be double or more than what would result without sprawl, will affect a region of Virginia, Maryland and the District of Columbia that already is considering harsh new rules on business and commuters to meet federal clean air standards.

Air pollution is increasingly implicated as a significant source of nitrogen and other bay pollutants.

The D.C. metro region already ranks as one of the nation's worst for traffic congestion, which is predicted to increase hugely even if a current, $5 billion shortfall for priority transportation projects is somehow covered. The considerable sums Virginia guarantees spend on Disney-related roadwork will divert more already-scarce money from areas where it's needed more, critics point out.

The project will remove thousands of acres from productive agriculture, and spinoff development will consume thousands more.

The theme park and its spinoffs threaten not only the region's scenic beauty but the integrity of a Civil War landscape that is part of the nation's heritage.

The tragedy is that Disney's decision to locate in the tourist-rich region is quite reasonable -- if the park were in the right location. A study commissioned by the Piedmont Environmental Council has identified 32 alternative sites, including several in Prince William County, and says there may be more.

What these sites have in common is that they are adjacent or close to existing roads, sewers and mass transit -- where development can occur efficiently, with a minimum of environmental and aesthetic impact.

But Disney and Virginia seem determined to plow ahead. Opponents see months and years of fighting to delay, hoping that as they educate people about the true costs of sprawl, the tide of public opinion will do to Disney what elected officials are too shortsighted to do.

It is a worthy battle, and more so because the travesty of this project differs only in size and visibility from what is happening everywhere. Usually it happens one shopping center or one strip development at a time, and never even makes the newspapers; but the pattern is the same, and collectively just as ruinous.

Regional approach needed

We can no longer afford to think of polluting, inefficient growth as a purely local land-use matter, any more than we could have done so with air and water pollution. Imagine if every county and state had set its own standards for clean air and water, readily compromising them anytime a big project came along.

Businesses, though they may not endorse every rule and regulation of federal air and water laws, will usually say a "level playing field" benefits them more than a welter of constantly shifting rules that differ from one place to the next.

Finally, a real disappointment in the Disney case is the failure by the Washington Council of Governments, the regional planning agency, to raise objections.

The council is great at producing reports on the problems of sprawl, yet continues the hypocrisy of one jurisdiction never criticizing another's follies, even when the results impact them all.