The Interior Department recently set out to determine the environmental impact of a natural gas pipeline from Alaska to the lower 48 states. The result was a 17-volume document, 9,570 pages long, 24 inches thick and 40 pounds in weight.

When the Federal Aviation Administration wanted to look at the alternatives to an Everglades jetport a few years back, it hired 23 different consulting firms, from meteorologists to sewage engineers, to prepare a report that cost $1.3 million.

The environmental impacts of the liquid metal fast breeder nuclear reactor took the Energy Research and Development Administration two years and 7,300 pages to chronicle.

At a time when President Carter has vowed to cut bureaucratic waste, environmental impact statements are a tantalizing target. Consultants who prepare them, federal and state officials who review them and lawyers who challenge them are increasingly convinced something has gone terribly wrong.

The EIS - as the statement is know in the trade "is the most criticized document since Internal Revenue's Form 1040," says Russell Peterson, former chariman of the President's Council on Environmental Quality, which reviews more than 1,000 EISes a year.

The EIS was a sleeper provision inserted at the last minute into the landmark National Environmental Policy Act of 1970. "Mayor federal actions significantly affecting the quality of the human environment" thence-fourth required a "detailed statement" or impacts, resources needed and alternatives available.

The provision gave the booming environmental movement of the early 1970s a major weapon. Suddenly, dams, highways, housing, projects, power plants any project that required federal funding or licensing - could be challenied in the adequacy of their Elees.

In seven years, more than 650 lawsuits were filed nationwide. Courts responded by forcing often recalcitrant federal agencies to prepare full impact statements, sometimes halting projects until agencies complied.

The impact statement originally forced the nation of pay more attention to the environment, but today it has lost its force. According to those who deal with EISes, the weapon has backfired, smothering both environmentalists and federal agencies in mountains of frequently irrelevant information.

"To protect themselves from further judicial review, the agencies have valuated every conceivable environmental impact of their proposed action, no matter how insignificant," says John R. Quarles, acting administrator of the Environmental Protection Agency.

"The result has been that the value of the final product is measured in inches rather than in quality of its analysis . . . There is a serious question if any of it is being read, much less relied upon by policymakers."

Peterson says he has read "a few EISes. That has been painful enough." Agencies, he said, "out of a desire to prove they are taking ecology seriously, frequently give us long lists of birds and bugs and plants, often in Latin as well as English."

Environmentalists have found that the National Environmental Policy Act provision has largely outworn it usefulness. "We ran out the string," said Robert J. Rauch, an Environmental Defense Fund attorney. "The old strategy of delaying projects by foreing agencies to write long impact statements isn't working anymore. The agencies have gotten wise to what they have to do."

Not that the result helps the environment much. EISes, Rauch said, are "full of irrelevant information. They set up straw men as alternatives to projects. They are more a rationale for decisions that are already made than a source of information."

More than 70 federal agencies produce impact statements - an average of four per working day. Moreover, 26 states have laws requiring environmental impact statements which often overlap or duplicate federal efforts.

The laws have spawned a multimillion-dollar industry of environmental consultants. Government agencies, short of manpower, contract out their EISes to university scientists, urban planners, private engineers and "environmental analysts."

In California, roughly 3,000 professionals specialize in environmental impact statements. Estimates of national EIS writers run to tens of thousands.

Last week a year-old organization, the National Association of Environmental Professionals, held its annual convention here. The declining reputation of the EIS was a major topic of a discussion panel on "How Much Is Enough Boon or Boondoggle"

James Thompson, an Arlington consultant, said the threat of lawsuits increases the size of EISes by 60 per cent. He also blamed government red tape. "The EIS team must satisfy 25 management levels . . . There's no penalty for including too much information, but you're in trouble if you leave something."

Thompson, a former FAA official, said the EIS on the Concorde airplane took up for volumes of 300 pages each, yet a 69-page decision paper drawn up later by former Transportation Secretary William Coleman "contained every bit of necessary information."

Herbert Pennington, the ERDA official who conducted the 7,500-page breeder reactor EIS in 1973-75, that if he could do it over again "it would come out about a quarter that size." But he added, "it's much more work to produce a small statement. You need astute editing to work it down."

On the positive side, the EIS has forced private industry to incorporate environmental considerations in early planning, according to W. Samuel Tucker, a Florida Power and Light Co. official. But "the maze of government bureaucracy" has forced his company to expand power plant EISes from 300 pages to eight three-inch volumes costing $6 million, he said.

The requirement that other government agencies comment on an EIS, "pushes you into detailed analyses," according to Norman W. Arnold, who overseas FAA impact statements. "It's not uncommon to get 20 or 30 sets of comments" from agencies like Interior, EPA. Agriculture, he said. "Some of the comments are frivolous, but you have to respond to them."

However, Arnold says the EIS has raised the department's environmental consciousness. For example, the impact statement on an airport for St. Thomas. Virgin Islands, changed the site from an ecologically fragile coral reef to a dump.

Environmental consultants are frequently criticized for producing EISes that justify projects rather than assess them objectively.

The environmental professionals association has drawn up a code of ethics intended to limit biased work. Until recently, "a lot of people were not committed to a level of professional judgment," said Carol Benson, a Bethesda consultant. "They would do anything to please a client."

An editorial last year in Science magazine criticized environmental analysts as "a traveling circus of scientists" with few credentials who produce" large, diffuse reports containing reams of uninterpreted and incomplete descriptive data."