PENSACOLA, Fla. – Documents show companies sharing liability for pollution from a defunct fertilizer plant avoided expensive groundwater cleanup after presenting skewed or incomplete data to federal regulators, a newspaper reported Tuesday.

As a result, arsenic, lead and other toxic chemicals may have seeped into Escambia County’s drinking water and will remain in an aquifer for decades, according to the Pensacola News Journal.

Pollution from the plant also may be responsible for radium, which can cause bone and nasal cancer, that tainted drinking water in parts of Pensacola and Gulf Breeze for at least four years, but that link has not been confirmed.

Conoco Inc., which last year merged into ConocoPhillips, owned the plant from 1963 through 1972. It was last operated by Agrico Chemical Co. before closing in 1975. Those two companies and three others that once had an interest in the plant – DuPont, The Williams Cos. and Freeport-McMoRan Inc. – entered an agreement with the Environmental Protection Agency to develop possible remedies when the property was declared a federal Superfund site in 1989.

Documents indicate the companies’ planned to use studies and design computer models to avoid the most costly remedy, which would have been to pump out and treat a plume of contaminated groundwater, the newspaper reported.

“Our goal was to see if we can establish beyond question limits of the plume that are smaller than EPA’s,” Conoco consultant Michael McDonald wrote in a 1992 memo.

The companies argued the plume, if left alone, would not contaminate drinking water or harm nearby Bayou Texar. They persuaded EPA officials that pumping would cause saltwater to seep into the aquifer although a Conoco consultant wrote in a 1993 letter to Williams officials that limiting it to 1 million gallons per day would minimize that potential.

The News Journal’s research may prompt regulators to revisit the decision against pumping, said Patsy Goldberg, an EPA official who had been remedial project manager for the plant site.

“If they pulled the wool over our eyes, we can go back and take a look at it,” she said.

The companies’ research avoided evidence suggesting the plume had contaminated water supplies at least back to 1958 when Pensacola closed a well because of it, the newspaper found.

In one instance, DuPont officials edited out parts of a 1993 study indicating the plume had caused high fluoride levels in the bayou, writing in the margins that the data “kills us.”

Houston-based ConocoPhillips and Agrico, a Williams subsidiary, denied misleading EPA but declined to answer specific questions because of a lawsuit by residents claiming the plume lowered property values and contaminated irrigation wells. Conoco repurchased the site in 1995 to oversee cleanup efforts.

“Conoco has met fully all investigatory and remediation processed deemed to be most protective of human health and the environment mandated by the EPA,” ConocoPhillips lawyer Reginald Bouthillier wrote to the News Journal.

Williams, of Tulsa, Okla., and Freeport-McMoRan, based in New Orleans, declined comment. DuPont, headquartered in Wilmington, Del., referred questions to ConocoPhillips.