Over time, regulations tighten, which can sap resale value

When we bought a house in New Jersey 19 years ago, our real estate agent told us, “When you buy a house, if you find gold on the property, it’s your gold.”

He went on. “And if you find a leaking oil tank, it’s your oil tank.”

Yes, sellers are supposed to disclose environmental hazards like lead paint or asbestos. But they can always plead ignorance. Getting them to pay for a cleanup after you’ve closed on the property is tough.

The New Jersey house we bought in 2001 came with an old oil tank. Before closing, we made sure it had been properly decommissioned — capped or filled with sand. That was the acceptable remedy at the time. But here’s where environmental hazards around a home get especially troublesome.

We had no trouble selling the home in 2004 when we moved to Texas, but had we held onto the house, we could have been on the hook for an expensive removal of the tank. By the time we moved back to New Jersey in 2008, the standard had gotten tougher. Even if oil tanks weren’t leaking, buyers and mortgage lenders wanted them gone. So before we bought a house that year, we hired a company that searched the property with a metal detector to make sure there was no buried tank.

Before buying a house, it behooves you to do some sleuthing to avoid unpleasant surprises. If you find a hazard, you can demand that the seller eliminate the problem or reduce the selling price. Or you can simply walk away from the deal. Required disclosures of toxic materials vary by state and locality. Best to educate yourself on what to expect, rather than wait for the seller or a real estate agent to do the job.

And a check of the surrounding neighborhood is also warranted. Living near a factory smokestack pumping out pollution can be as hazardous as toxic materials on your land.

Industrial pollution

What the land was used for before houses were constructed matters. The land might have been an orchard where powerful pesticides were used. Or a factory where dangerous solvents and heavy metals were used. Or a military base where fuels and hazardous wastes were stored.

For current emissions in the area, start with the Environmental Protection Agency’s Toxic Release Inventory map.

You can also ask state and local environmental agencies and check with local zoning and building permit agencies about past uses of the land.

Nowadays, many brownfield sites are turned into safe residential neighborhoods. But it often takes millions of dollars in cleanup before the soil is OK to build upon.

Builders of subdivisions weren’t nearly as careful in the past as they now. In one of the country's worst contamination cases, New York state’s Love Canal, houses were built over a dump containing hazardous wastes, including carcinogenic chemicals.

If you plan to knowingly buy a contaminated property, get estimates of how much it will cost to clean it up first. Buy an environmental liability insurance policy. Such policies typically have high deductibles but can protect you against unexpected clean-up costs or bodily injuries or property damage from polluted soil or water.

Underground tanks

The abandoned oil tank on your property isn’t the only worry. Thousands of older service stations have leaking tanks that can pollute groundwater nearby. Cities try to force property owners of former service stations to do cleanups, but court battles can stretch on for years. Buying a home near a service station with leaking tanks — or tanks that will later leak — is a bad idea.

Lead pipes

Houses built before 1986 commonly had pipes made of lead, which can contaminate drinking water.

Even low levels of lead in the blood cause health issues, and replacing lead pipes is expensive. Have a water-quality test done before you buy an older house. And make the seller remediate any lead problem.

It’s not just lead pipes. Common sources of lead in water include faucets and fixtures, as well as solder in pipe joints.

Lead paint

If your home was built before 1978, it is likely to have lead-based paint. That was the year the federal government banned consumer sales of such paint, though some states banned it earlier.

Lead paint is particularly dangerous to children. It is still present in millions of homes, sometimes under layers of newer paint, according to the Environmental Protection Agent. Lead paint also can contaminate soil around the house.

You can get inexpensive tests for lead paint at your hardware store. But lead paint removal should only be done by professionals who can safely dispose of the lead-tainted paint chips and dust.

Lead paint isn’t considered hazardous if it is well-maintained and not peeling. But you can imagine a day in the future when it will be difficult to sell a house with lead paint.

Asbestos

This mineral was once regarded as a miracle substance, commonly used for decades in everything from insulation to flooring to exterior shingles.

Asbestos isn’t dangerous unless it’s disturbed and its fibers are dispersed into the air. Just like lead paint, cleanup or remediation is dangerous and should only be done by professionals. Often the cheapest fix is to contain the asbestos, not to remove it.

Radon gas

This odorless gas can cause lung cancer and is present in high levels in some homes. Make sure your building inspector does a radon gas test before you buy a home.