It was an image that defied description: In June 1969 the Cuyahoga River near Cleveland, Ohio, was so polluted with industrial chemicals that a spark from a passing railcar caused the water to burst into flames that soared 50 feet high and spread downriver.

The Potomac River, flowing through the nation's capital, was so polluted it was considered "a severe threat" to anyone who came in contact with its water. Lake Erie was termed "biologically dead;" major waterways, like the Mississippi River, were little more than open sewers; fish kills were at record levels; and most of the nation's raw sewage was simply dumped untreated into streams and rivers.

"The rivers of this country serve as little more than sewers to the seas," said then Sen. Edmund Muskie, who served as chairman of the Senate's Subcommittee on Air and Water Pollution, and introduced legislation that, after a dramatic congressional override of President Richard Nixon's veto, become the landmark Clean Water Act.

Oct. 18 marked the 30th anniversary of the legislation and, according to a presidential proclamation, the start of the Year of Clean Water.

Today, the Cuyahoga River is no longer combustible; the Potomac is widely used for recreation; Lake Erie has slowly come back from the dead; and nearly all Americans have sewage treatment. The Clean Water Act is considered one of the most successful environmental laws on the books.

It has not, however, been without its headaches, as is the case with virtually any federal regulatory program. Farmers have endured a lot of ham-handed actions by governmental agencies, often administered by officials who hadn't a smidgen of knowledge about farming.

Overall, though, much good has been accomplished:

• In 1968, only 86 million U.S. citizens were served by modern sewage treatment facilities; today, 97 percent are served by wastewater treatment facilities.

• In 1972, only about one-third of U.S. waterways were considered swimmable, fishable, and safe for drinking. Today, nearly 55 percent meet those standards.

• Pollutants released into the nation's waterways have been cut by 700 billion pounds.

• The nation is close to halting the overall loss of wetlands, and in the past decade hundreds of thousands of acres of habitat have been preserved, restored, or created.

But much remains to be done, as Environmental Protection Agency Administrator Christie Whitman noted: "I believe water is the biggest environmental issue we face in the 21st century, in terms of both quantity and quality. Many of the nation's waters still do not meet water quality goals."

And, environmental groups point out that, in violation of the law, nearly 260 million pounds of sewage and toxic chemicals are dumped into our waterways annually; some 60,000 acres of wetlands are lost yearly; and many waters off the nation's beaches are still unfit for swimming, hurting tourism and local economies.

Many are concerned, too, that the Bush administration will dismantle significant portions of the act, and are urging Congress and the public to pressure the administration to continue programs to clean up polluted waters.

e-mail: hbrandon@primediabusiness.com.