The Department of Veterans Affairs announced Tuesday that it will soon start to cover out-of-pocket health-care costs for Marine dependents who contracted cancer and other illnesses from toxic water at Camp Lejeune, as promised two years ago by law.

In 2012, Congress passed the landmark Honoring America’s Veterans and Caring for Camp Lejeune Families Act.

It provided health care for Marines and family members who had lived on the base near Jacksonville, N.C., from 1957 to 1987 and who had suffered from any of 15 illnesses named in the law. These included cancer related to the lungs, bladder, breasts, kidneys and esophagus, as well as leukemia and problems involving female infertility.

About 750,000 people were exposed to drinking water at the base that was polluted with chemicals that included industrial solvents and benzene from fuels. The chemicals resulted from spills, a dump site on base, leaking underground storage tanks on base and an off-base dry cleaner.

Under the 2012 law, VA immediately offered full care for veterans who had been stationed at ­Lejeune, but it told their dependents who suffered from covered illnesses that they would have to wait to be reimbursed.

The announcement of final rules on Tuesday meant that later this year the agency will start to reimburse family members under the 2012 law for costs since March 26, 2013, that were not covered by insurance. The date is when Congress appropriated funding. The rules first must be published in the Federal Register, to be followed by a 30-day waiting period before people can file claims.

VA officials also planned to release a document about health-care services to veterans who were on active duty at the base for at least 30 days in the three-decade period.

Retired Marine Master Sgt. Jerry Ensminger, whose 9-year-old daughter, Janey, died of leukemia in 1985, and Mike Partain, who was born at the base and suffered from male breast cancer, led a long fight to get the law passed. Both said Tuesday that they were dismayed it took two years to put it into effect.

“As far as I’m concerned, so many people have already died. They just keep dragging this thing out,” Ensminger said.

Partain said “institutional apathy and incompetence” were the reasons it took two years to write and approve the regulations for how the law would be administered.

VA wrote the regulations, and then the Office of Information and Regulatory Affairs, part of the White House Office of Management and Budget, had to approve them. The office’s Web site said approval was made Sept. 9. The White House referred questions to VA officials, and the agency did not respond to a question about the length of time required for the implementation of the law.

Sen. Richard Burr (R-N.C.), who proposed the legislation, said in a statement that the final regulation “has been a long time coming.”

“Unfortunately, many who were exposed to the contaminated water have already died as a result of their exposures and will not be able to receive the help this law provides,” Burr said. “I fully expect VA will now move swiftly to implement all the regulations and extend a helping hand to the victims of this tragic episode in our nation’s history.”

Sen. Kay Hagan (D-N.C.), who joined Burr in pushing for the legislation when she became a senator in 2009, said her office had been urging VA to finalize the regulations since Congress passed the bill.

“I am relieved that action has finally occurred today,” Hagan said. “Our veterans and their families exposed to toxic water contamination have waited too long for answers, and I am pleased they will now begin to receive the critical health-care benefits they deserve.”

For veterans, any reimbursement of co-payments would go back to Aug. 6, 2012, when the law was signed. The law does not provide veterans with disability compensation.