MORGANTOWN, W.Va. (AP) — Environmental regulators want DuPont to submit plans for determining whether seepage and runoff from the site of a former zinc-smelting plant in north-central West Virginia are contaminating groundwater or streams.

A resident who lives near the former smelter in Spelter went to the state Department of Environmental Protection earlier this year with concerns about both new seeps she spotted at the site and surface drainage ditches that go into Simpson Creek.

DEP project manager David Hight says it's unclear whether either is causing contamination offsite, but DuPont must submit a plan to find out using either water sampling or new community wells, or both.

Monitoring wells onsite do show contamination, he said, but DEP can't tell whether that contamination is going beyond the property lines.

"It may be," he says. "We don't know."

Although there's no deadline for the plan, Hight expects it to be submitted soon.

DuPont spokesman Dan Turner said the company routinely samples groundwater and monitors the Spelter site, the West Fork River, and where the river meets Simpson Creek. It turns those results in to DEP.

"Based on WVDEP's recent request," he said in an email Thursday, "we will add more sampling points in Simpson Creek."

The smelter in Harrison County produced more than 4 billion pounds of slab zinc and 400 million pounds of zinc dust for use in rustproofing products, paint pigments and battery anodes. By 1971, a toxic waste pile filled with arsenic, cadmium and lead stood 100 feet tall and covered nearly half of the 112 acres.

The plant closed in 2001, and DuPont worked with state regulators to demolish buildings and cap the site.

Thousands of residents later sued over exposure to the toxic metals. In 2007, a jury ruled DuPont had been negligent in creating the waste pile, and that it had deliberately lied to its neighbors and downplayed possible health threats. It awarded $380 million in punitive damages — an amount the state Supreme Court later cut to $196 million.

The high court affirmed that residents were entitled to a 40-year medical monitoring program and a cleanup fund for private properties. But those verdicts were later wiped out when DuPont dropped its appeal and offered a $70 million settlement that included $4 million to be set aside for cash payments to people who are eligible for medical monitoring.

DuPont is just beginning a new medical monitoring program, consisting largely of blood and urine tests that can help determine whether a person has any detectable level of the relevant heavy metals. The program will last for 30 years because some diseases, including skin, liver, bladder and lung cancers, can take decades to manifest.

Groundwater under the site is not accessible under an agreement with Harrison County health officials, Hight said, so there's no immediate threat to public health. Nor have DEP inspectors seen surface water leaving the site. And quarterly sampling at the mouth of Simpson Creek has found no contamination for the past several years, he said.

Residents have reported orange staining of rocks, but Hight said contamination — most likely iron — is coming from an old mine portal. Several mine portals on the DuPont site were sealed during the site capping, but one was offsite and wouldn't have been included in that project.

Meadowbrook resident Rebecca Morlock, who has been party to several lawsuits against DuPont, is skeptical of both the company and the DEP. She believes contamination from the site still has pathways to humans, and she considers it "absolutely a continuing health threat."

"We plant gardens here. The roots of vegetable plants uptake metals," she said. "We eat that stuff and have our whole lives. What about the animals? We have had animals drop dead since I was a little girl."

Morlock also worries about her grandchildren, who play outside.

"Am I supposed to go buy one of those Tyvek space suits from DuPont so we can enjoy our property?" she said. "They have stripped our rights to even enjoy our natural resources that God provided."