The first payouts in a $375 million settlement involving the former Rocky Flats nuclear weapons plant and its negative effect on downwind property values could hit claimants’ mailboxes by the end of the month.

Merrill Davidoff, a Philadelphia lawyer whose firm is administering claims in the 27-year-old legal case against two of Rocky Flats’ private-sector operators, said final approval from a federal judge is needed before money can start flowing to approximately 7,500 households with valid claims.

Barring any delays from the court, checks should start going out by the end of October.

“We are trying to get money out to claimants as soon as possible,” Davidoff told The Denver Post Monday.

Davidoff said more than $200 million will be paid out to those whose homes lost value after it was determined that plutonium released at Rocky Flats was carried by prevailing winds to a swath of Broomfield, Westminster and Arvada homes that lie directly east of the former weapons manufacturing plant.

He said settlements will likely come in two disbursements — one this fall and the second sometime next year. The bulk of the money — $120 million worth — will go out in the first check, Davidoff said.

“There’s a reserve being held for later approved claims,” he said.

Davidoff said the bulk of individual compensation claims lie in the $15,000 range. Some claims are only a few thousand dollars, while some go as high as $36,000.

“It’s a factor of what was your assessed value back in 1989,” Davidoff said.

The plaintiff class includes all those who owned property in the affected area as of June 7, 1989 — the day after the FBI raided the plant. Anyone who sold their property before that date and anyone who purchased property after that date did not qualify.

Davidoff said a few thousand claims that were filed after the May 2016 announcement of the settlement from the plant’s operators, Rockwell International Corp. and Dow Chemical Co., have been deemed invalid for various reasons.

The payouts would put an end to a case — dubbed Cook et al. vs. Rockwell International — that began in 1990 and has been through multiple bends and turns in federal court since.

In 2006, a jury ruled in favor of the plaintiffs, and a federal judge awarded them $926 million. But four years later, that award was thrown out by the 10th U.S. Circuit Court of Appeals.

The 6,500-acre Rocky Flats, 16 miles northwest of Denver, opened in 1952 to manufacture plutonium triggers for the nation’s nuclear arsenal. Dow operated the plant until 1975, when Rockwell took it over and ran it until 1989.

It formally was shuttered in 1992 and underwent a $7 billion cleanup that concluded in 2005. It is now a national wildlife refuge, although a 1,300-acre core area where weapons production occurred remains a Superfund site and off-limits to the public.

In 1992, Rockwell settled with the Justice Department and pleaded guilty to 10 violations of the Clean Water Act and federal hazardous-waste laws, including illegal storage of hazardous waste. The company paid $18.5 million in fines.