Neville Chemical Co. has paid a $9,000 fine for discharging elevated amounts of four toxic chemicals into the Ohio River at its production facility on Neville Island.

According to the state Department of Environmental Protection, the fine was for excess discharges of volatile organic compounds, or VOCs, that occurred from October 2005 through January 2006 and violated the limits of the company's pollution discharge permit.

"Neville Chemical is paying the price for poor performance and its failure to meet its obligation to protect Pennsylvania waterways," said Kenneth Bowman, DEP regional director.

VOCs include a variety of chemicals widely used as ingredients in household products and commercial and industrial processes. The four VOCs discharged into the river by Neville -- toluene, benzene, xylene and 1,2 dichloroethylene -- are used to manufacture hydrocarbon resins and related products used in the manufacture of paints, adhesives and rubber goods.

Benzene is a carcinogen and the other chemicals are flammable and can affect brain function and the nervous system. The amounts discharged into the river were not at levels high enough to kill fish but exceeded the amounts allowed in the company's National Pollutant Discharge Elimination System permit. One January discharge of toluene was more than double the allowable level.

"The department limits the amount of pollutants that can be discharged into the waters of the commonwealth in order to maintain the health of those waterways," said Helen Humphreys, a DEP spokeswoman.

Neville Chemical has been the subject of repeated DEP enforcement actions, penalties and court orders concerning chemical contamination of surface and groundwater during the last two decades.

During an 18-month period in 2001-02, chemical and hazardous waste oils seeped out of the ground at Neville Chemical's production facility and produced a sheen on the Ohio River. The seepage came from a layer of pollutants that has drained into and now floats on top of groundwater under the company's Neville Island plant.

In April 2005, the company settled civil penalties totaling more than $13 million for allowing the seepage by agreeing to spend $2 million to pump and treat the contaminated groundwater. It also agreed to pay a stipulated penalty for any appearance of the sheen on the river through 2008.

The recent discharges stem from efforts to correct the groundwater contamination, according to the chemical company.

Jack Ferguson, the chemical company's vice president of manufacturing, said the latest discharges occurred because the company's old treatment facility was unable to handle the large volume of groundwater pumped from a new well system.

"The permit for the new treatment system wasn't ready so we continued to use the old system and it was not able to treat the water sufficiently," Mr. Ferguson said, adding that the new treatment system was put into operation sometime during the first few months of 2006.

The performance of the new equipment is being evaluated and adjusted, he said, and acknowledged that an oily sheen still occasionally appears when river levels below the Emsworth Dam change dramatically.

Ms. Humphreys said a sheen has been detected on the river on "multiple occasions" and the company has been fined for those violations.

The company, founded in 1925, locked out its 150 hourly workers at the beginning of August. The lockout is continuing but is not affecting operation of the water treatment equipment, Mr. Ferguson said.