More than 30,000 military veterans and service members have formally agreed to 3M's settlement over allegedly faulty earplugs, prompting 3M to issue $253 million in payments earlier than expected.

The payments will be made by the end of the month to several thousand plaintiffs who were preparing to go to trial as the settlement was drafted and "have now agreed to participate in the settlement and release their claims," 3M said in a news release this week.

3M previously set aside $250 million in initial payments for more than 30,000 claimants at the end of December.

The milestone is significant because a nearly unanimous level of acceptance is needed from the 276,000 claimants in order for the $6 billion settlement, announced last summer, to be valid.

"We are pleased with 3M's decision to move up this payment and appreciate its commitment to the resolution of these claims," an attorney for the plaintiffs, Bryan Aylstock, said Tuesday. "So far, support for the settlement has been overwhelming and we expect to meet and indeed exceed the 98% participation threshold provided for in the settlement agreement in the coming weeks."

The Maplewood-based company announced the settlement in August after nearly five years of litigation amassed into one of the largest mass torts in U.S. history.

More than a quarter-million veterans and active service members blamed hearing damage on Combat Arms earplugs, made by 3M subsidiary Aearo Technologies and sold to the military from 1999 to 2015. 3M, which acquired Aearo in 2008, maintained the earplugs were safe when used properly.

3M says the settlement "has received strong and widespread support from claimants and the broader military community." The company can walk away from the remaining settlement payments if the 98% participation threshold is not met, though 3M is not required to do so.

Earlier this month, a federal judge signed off on 3M's plan to issue $1 billion in stock to help pay for the settlement. Payments will be made in phases through 2029.

The larger settlement 3M announced last year, involving PFAS contamination in drinking water, heads to a final hearing next month. The class-action deal with public water systems is worth up to $12.5 billion.

That settlement also requires a certain percentage of claimants to participate, but that threshold is not public. According to court filings, 170 valid opt-outs were received out of more than 14,000 potential class members.

"The relatively small number of opt-outs and overwhelming class member participation in the settlement ... demonstrates overall support for the settlement," attorneys for the water systems wrote last month.

The judge overseeing the case previously warned skittish cities and public utilities to accept the settlement or risk languishing in litigation into the 2030s.