The Navy is seeking public comment on a proposal to spend $1.2 million to reduce potential exposure to chemicals at a Barbers Point landfill where asbestos and burned municipal waste were in trash dumped between 1942 and 1997.

Surface soil contains antimony, lead and hydrocarbons that exceed state Department of Health action levels, the Navy said.

The Navy is proposing to add cover material, put in place erosion control measures, add perimeter warning signs and conduct a review every five years at the industrial site in an old coral pit south of Runway 11 at Kalaeloa Airport.

The Barbers Point Sanitary Landfill is adjacent to the site of a 2003-04 operation to cleanse more than 44,500 cubic yards of soil contaminated with polychlorinated biphenyls (PCBs) that were collected from 14 military installations around Oahu. A thermal treatment plant was brought in to bake the soil at 900 degrees to remove PCBs as sludge.

A coral pit used to generate fill and road-base material in the early 1940s was subsequently used for the landfill, the Navy said.

“Bagged asbestos was reportedly disposed of at the site between 1976 and 1991,” the Navy said in a synopsis of the mitigation plan. “According to historic reports, municipal waste was burned and placed in the landfill, then covered with coralline soil from a nearby coral pit. A landfill cover of compacted gravel and sand was placed over the site prior to closure in 1997 as a final waste containment measure.”

A Navy review between 1994 and 1998 indicated that chemicals of potential concern were not present in concentrations that could pose a risk, but the report was reviewed in 2011 and found to have “data gaps” over the characterization of the surface soil, the Navy said.

Under the Comprehensive Environmental Response, Compensation, and Liability Act, also known as Superfund, the Navy is responsible for the investigation and cleanup of contamination resulting from its past operations.

The landfill, consisting of about 4.8 acres, no longer is in operation, but is part of the Navy’s Solid Waste Management Facility, which takes in green waste and sewage sludge.

The landfill cover was maintained as a vegetated surface until 2009, when heavy rain caused flooding and erosion of the cover, the Navy said. Compost material was spread across the surface, but charred wood and plastic started to become visible.

The $1.2 million mitigation plan is the Navy’s “preferred” alternative among several being considered. The most expensive would be the $42 million removal and disposal of soil and debris down to 10 feet.

Ewa Beach historian John Bond said he has concerns over the contamination remaining in the ground. Army Air Corps photos from 1928 show a karst sinkhole pond mauka of the landfill site, and “anything you put in the ground there is going to leach right down into the water table and into the ocean,” he said.

Bond said the Navy mitigation plan is new to him and other community members and that further review of the alternatives is needed. The state Department of Health in December said it concurred with the Navy’s preferred plan.

Public comments will be accepted through Thursday. The Navy said it will select a course of action for the site after reviewing the comments. Naval Facilities Engineering Command Hawaii can be emailed at denise.emsley@navy.mil. The command also can be reached at 471-7300.