Beechel Grays and 700 of his neighbors got $2,300 checks today--shares of a $24 million out-of-court settlement with Olin Chemical Corp., which dumped at least 475 tons of DDT into local creeks over 17 years.

As neighbors drove by yelling, "We got it, we got it," Grays clutched his check beneath a hackleberry tree and said, "This is about the happiest day there has ever been in Triana, but I'd give the money back if they could take all the poison out of my body."

Triana is the kind of American nightmare Rachel Carson prophesied, a poor black town that drew its water and its catfish from a muddy creek contaminated with pesticides. Indian Creek carried polluted waste water from a now-defunct DDT plant Olin leased from nearby Redstone Arsenal.

Under fire from wildlife activists, the plant shut down in 1970. Two years later DDT was banned. But no one told Triana it was poisoned until 1978.

Mayor Clyde Foster says he heard about the DDT from a reporter and telephoned the federal Centers for Disease Control in Atlanta for help. A research team was dispatched, and found that residents like Grays had more DDT in their bodies than any non-industrial workers in the country. One man had a heart attack when he got his test results.

But today the mood was upbeat, Deliverance Day in Triana, with whole families waiting all day for mailman Gregg Barlowe to deliver 705 checks, and asking everyone in sight if theirs had arrived. "I feel like shoutin' and huggin' him," said Mary Lee Rice, 67, "but his wife might shoot me."

"I've had a thousand people flag me down to ask where the checks are," said Barlowe, 26, sweating as he whipped his white Jeep past the fresh-turned fields of red clay. "There's going to be a lot of drunk people celebrating in Triana tonight."

Alfred Horton, 76, was itching to trade in his prehistoric Chevrolet for a newer Chrysler. Mary Rice aimed to buy a "little" house, and Ollie Jackson, 66, a retired farmer, marveled, "The money makes it easier to take. At least I can pay a doctor if I feel bad."

Under the settlement, every man, woman and child in Triana--about 1,100 people--and 31 commercial fishermen nearby whose livelihoods were destroyed will receive about $10,000 each. Today's checks were the first installment. Five million dollars was set aside for a medical program for residents, and Olin has agreed to bring the DDT levels of the plentiful bream bass and buffalo fish down to FDA-acceptable levels of 5 parts per million within 10 years. One government agency estimated that the costs of DDT cleanup could run as high as $90 million.

Had the case gone to trial, Atlanta attorney Robert Shields, chief lawyer for Triana residents, was prepared to advance a novel legal theory that avoided "the impossible task of trying to prove a given person had a given disease as a result of exposure to DDT."

Instead he argued that residents should be compensated for the "risk from future injuries" that may never materialize. Olin agreed to settle in December to avoid a long, costly court battle, a spokesman said, and signed the final judgment this week.

Not everyone, however, said the money would cure the uncertainty and stress of DDT in their blood and the blood of their children. "Money can't ever buy back our health. It couldn't bring Howard Hughes back to life," said Marvalene Freeman, an outspoken plaintiff. "We're walking dynamite."

Many residents like Virginia Harris, 73, attribute whatever ails them to DDT anxiety. "Since the DDT came, a lot of people have died and some of it came from worrying. I felt like a teen-ager until I got those blood tests."

DDT, once widely used on crops for pest control, kills insects by affecting their nervous systems. Long-term exposure has caused cancer in test animals.

Although its effect on humans has not been documented in the laboratory, Dr. Kathleen Criess, the CDC's Triana field director, found some correlation among DDT, high cholesterol, elevated blood pressure and liver function in many Triana cases.

"No one has any evidence DDT causes cancer in humans, but when people are concerned, caution is advised," said Criess. "We just don't know what the long-term effects might be from exposure to chemicals, to DDT. What Triana needs is good medical care so if there are an increase in diseases like cancer, it can be detected."

Most Triana residents heed government warnings to avoid fishing the creeks and rivers, but many poor blacks like Hattie Fletcher, 66, depend on fish to survive and still catch perch for supper from DDT-infested Indian Creek. "This is what I ate for years and they don't seem to hurt me," she said, casting a worm into the creek.

"If the money comes, I'll be a happy soul. We all got to die of some kind of disease some day," reflected Felix Wynn, 88, who had the highest DDT level detected in town--more than 3,000 parts per billion compared with the national average of 15.

"People may be jubilant now when they receive their checks," said Mayor Foster, 51, director of equal opportunity at the Marshall Space Flight Center here. "But what will be their reaction downstream if they learn those contaminants caused their ill health?"

Federal officials at Wheeler Wildlife Refuge found a serious drop in migratory birds as early as 1959, and the U.S. Army Corps of Engineers reported high DDT levels in creek sediments in 1963.

But the Army didn't pressure Olin to clean up its plant until 1969. One year later, Alabama conservation officials found DDT and PCBs in the catfish and carp. In 1977, Army researchers estimated DDT levels in fish as high as 600 parts per million--far higher than federally approved safe levels--and issued a warning.

Angry commercial fishermen sued Olin for $50 million after their river fish were ruled too contaminated for sale. Triana residents later joined that lawsuit.

Howard Veller, deputy regional administrator for the EPA in Atlanta, recalls that the Olin plant shut down after EPA's predecessor agency set discharge limits Olin could not meet.

"We thought we had solved the problem," he said. But it was not until Redstone officials came back to EPA six or seven years later with figures showing high DDT levels in fish "that this came into focus. Keep in mind, that was a number of years ago. It's not easy to judge an environmental response in 1969 with a 1983 conscience and awareness of toxic, hazardous waste."