Toxic Tidbits, via the Web

HAVE you ever wondered about health hazards lurking underground near your home, your workplace or a property that you are thinking of buying or renting?

For locations in New York State, there is now an easy way to find out, without resorting to costly testing of groundwater and soil core samples. A free Web site enables anyone — including prospective buyers and sellers, brokers and neighbors — to check a location by typing in its address.

The site responds with an interactive map pinpointing any nearby documented hazards — and there are thousands of them across the state.

“It’s a way for people to find out known or potential environmental threats and help them make decisions to protect their health and the community’s well-being,” said Walter Hang, the founder of Toxics Targeting, an environmental data firm in Ithaca that set up the Web site.

Starting Sunday, the maps are available by clicking on “free toxic site maps” at www.toxicstargeting.com. Mr. Hang said he was unaware of any comparable site elsewhere in the country.

For many populated areas in New York state, the site also offers three photographic functions to help orient viewers. It shows a Google satellite picture overlaid with the names of local roads, a "bird’s-eye view” picture with a closer-in image of buildings and other landscape features, and street-view scenes as if seen by a pedestrian.

When people learn of nearby hazards, they can pressure government regulators to require cleanups or perhaps sue those responsible for the contaminations, Mr. Hang said. He worked for 12 years as an environmental advocate at the New York Public Interest Research Group.

The buyer-beware maxim is especially pertinent to environmental issues in real estate. Engineers hired by prospective buyers typically check structural integrity but exclude environmental hazards from their evaluations. And while the law requires home sellers to disclose known problems, nondisclosure is permitted if the sale price is cut $500.

Someone considering buying or renting property who learns of a serious hazard could decide to back out, seek a lower price or ask the owner to pay for a cleanup.

Commonly found hazards include gasoline station and heating oil tank leaks, industrial waste dumps, dry-cleaning fluid spills and other dangerous chemical plumes — some of which migrate thousands of feet from the original point of contamination, Mr. Hang said.

About 30,000 documented hazards are listed across the state, he added. His firm also lists about 240,000 other places with potential or as-yet-unclassified hazards.

“Gas and fuel tank leaks, dry cleaning fluid, industrial degreasing solvents — we see that all the time,” said Paul T. Stewart, president of Advanced Cleanup Technologies in Farmingdale, which investigates pollutants for commercial, industrial and apartment properties. “These Web site maps are useful in making people aware of risks, a tool to educate the public.”

People wanting more information about specific hazards can buy a detailed report from Mr. Hang’s firm for $150 for a typical property. The reports usually identify the pollutants, the quantity, the geographic spread and any cleanup efforts.

The firm also sells reports on large properties and on wider areas to municipalities for planning, to water utilities safeguarding their wells and to developers and real estate companies.

People can also request the environmental information from government agencies, but Mr. Hang says his database has more comprehensive information, compiled from a variety of agencies.

Examples from his company’s files include a 1996 Sunoco gasoline station leak in Valley Stream, Long Island, which produced fumes in a six-story building that prompted the fire department to order an evacuation, and leaks from an old fuel oil tank at a home in St. Albans, Queens, that created odors in the basement and had occupants complaining of headaches.

“Some spills are trivial,” Mr. Hang said. “Then we have a 30-million-gallon oil spill in Greenpoint — a lake of oil.”

A version of this article appeared in print on August 31, 2008, on page RE8 of the New York edition.