A Baltimore concrete plant operator has been fined $150,000 after pleading guilty to discharging concrete slurry into the Patapsco River in Cherry Hill.

The company, D&G; Brice Contractors Inc. of 2901 Waterview Ave., was convicted on four counts of polluting state waters, and two counts of operating an industrial facility without a discharge permit.

Baltimore Circuit Judge Evelyn O. Cannon imposed the penalty, then suspended $50,000 of the fine and placed the company on 18 months' probation.

The Maryland attorney general's office said that between August last year and August this year, Brice repeatedly allowed concrete slurry from the mixing plant to escape from a settling pond and run off its property. Wash water from an area where mixers and dump trucks were cleaned also escaped, they said.

The alkaline effluent reached an unnamed stream that flows into the Patapsco, causing discoloration and increased levels of alkalinity and suspended solids, according to the attorney general's office.

The company's previous discharge permit expired in August 2000, and the pollution would have exceeded levels allowed under that permit, according to a statement of facts accepted by both sides in the case.

Assistant Attorney General Hans Miller said the criminal case and the large fine resulted from Brice's failure to respond to earlier enforcement efforts.

The company had been cited and fined $50,000 before by the Maryland Department of the Environment. "It didn't stop the pollution," Miller said.

Attempts yesterday to reach company officials for comment were unsuccessful.

MDE spokesman John Verrico said that most of the pollution occurred when it rained. An "old estimate" of the amounts involved was 5,000 to 10,000 gallons a day.

Verrico said the company will not be issued a new discharge permit until it wins state approval for a discharge treatment plan. In the meantime, he said, excess runoff from the property is being stored on site in tanker trucks.