CAPE MAY POINT — An undetected fuel-oil leak, a high water table and sandy soil were all factors in a Lighthouse Avenue woman’s all-too-common experience with home heating-oil tanks.

Located next to an outdoor shower, under a roof that did not have a gutter, and next to an old abandoned septic field that gave the fuel oil an easy route to the groundwater, oil from the leaking tank followed the drain pipe of the septic system to the water table, said Paul DeBlasio, of Northstar Environmental Services in Dennis Township.

Before the ordeal was over, the yard looked like a bomb had hit it as Northstar dug out an estimated 200 tons of oil-soaked soil. The company also brought in equipment to remove the oil from 450,000 gallons of groundwater. The hole was so deep, the company had to put in metal piling to keep the modest one-story house from falling into it.

The final cost was more than $100,000, and insurance, as is usually the case, did not cover it. Homeowner Pat Casey, who lives in Hawaii and was renting out the house, now plans to sell it, said her cousin, Ernest Heegard, who lives nearby on Alexander Avenue.

“It was a pretty traumatic thing. No insurance covered it, and it hit her hard,” Heegard said.

There are thousands of such tanks in the state and little money to clean them up. Hurricane Sandy brought the issue to the forefront, as high water levels lifted up oil, which is heavier than water, from old tanks buried in many barrier island communities. Often, the location of the tanks is not even known until there is a problem.

“The floods came to the barrier islands, and water displaced the oil. We had a red (fuel oil is red) sea in Ventnor as oil in the tanks just came out. It stained the fences red,” DeBlasio said.

Sandy uncovered a tank in Longport that was under a concrete floor in a utility room, said Steve Russell, Northstar’s health and safety officer.

DeBlasio said a tank was discovered in Brigantine by a homeowner jacking up his house to a higher elevation to avoid future floods. In another Longport case, oil came up under the house and soaked the floor joists and was sucked up into the sheetrock.

“There is an abundance of them on the barrier islands from Brigantine to Cape May. A lot of older homes have them. The saltwater is so high it corrodes the bottom,” DeBlasio said.

Northstar removes about 40 such tanks a year and cleans up the soil and groundwater. DeBlasio is a Licensed Site Remediation Professional, or LSRP. A few years ago, the state Department of Environmental Protection, hoping to get more tanks removed and more quickly, set up the LSRP program to encourage private enterprise to get involved. DeBlasio said the LSRP license required 10 years experience along with exams and ethics checks.

Bob Considine, a spokesman for the DEP, said there are 15,862 regulated underground tanks in the state. Those are the ones the state knows about, but it does not account for residential heating-oil tanks.

“We do not have any statistics on the number of homeowner heating-oil tanks within the state,” Considine said.

After Sandy, the DEP inspected many of the regulated tanks and found 40 that may have leaked during the storm, Considine said.

The DEP regularly inspects the regulated tanks and registers a 90 percent compliance rate in terms of detection and prevention, but residential fuel oil tanks are neither regulated nor inspected.

Most of the tanks presenting problems are buried, although the Lighthouse Avenue tank was not underground.

“There are still a ton of underground oil tanks in use, and nobody knows until they go to sell their house,” DeBlasio said.

When homeowners began burying the tanks is unclear, but DeBlasio said the oldest one he has heard of was in Atlantic City dating to the 1920s.

To find buried tanks, Northstar often simply has to trace piping, although for more difficult cases, it uses ground-penetrating radar.

“It’s a sonar survey of the ground. If radar hits metal, it makes an image on the computer,” DeBlasio said.

Clay can stop the oil from moving, but in sandy soils it sinks until it hits groundwater and floats on top of it, but often moving horizontally. Northstar found oil at 24 feet at a job in Franklinville, Gloucester County, and more than 25 feet in Vineland, but Russell said groundwater is usually at about 6.5 feet in the shore towns. DeBlasio said the good thing is that the high groundwater stops the oil from going deeper.

After finding the tank, they take soil samples to find the vertical and horizontal extents of the spill.

Besides excavating soil and replacing it with clean fill, the firm uses an 80 gallon-per-minute mobile groundwater treatment system.

Barrier islands present special problems because the groundwater is usually influenced by the tides and is corrosive because there is salt in it. On islands with small lots, Northstar often has to dig them out by hand, because there is only a few feet of open space between homes, and the side yard is where the tanks are often buried, though DeBlasio said he has found them under driveways, front porches and beneath later additions to homes.

DeBlasio said the average cost is between $25,000 and $30,000, though the firm did one job for more than $200,000.

“We have a ton of clients who don’t know what to do, because they don’t have $25,000 to $30,000,” DeBlasio said.

Some towns require removal and cleanup before a house can change hands. Some banks and mortgage companies require removal before they will lend money. Some insurance companies won’t write homeowner policies if there is an underground tank.

Funding is available from grants and low-interest loans through the DEP and the New Jersey Economic Development Authority, but it does not keep pace with applications. Considine said 1,927 applications are pending for total claims of $49.7 million, but only about $9.6 million in funds are available right now.

“They’re not taking on any new applications,” DeBlasio said.

Contact Richard Degener:

609-463-6711