Hauler Under Probe for Dumping of Sludge at Farm : Investigation: Authorities are looking to see if a San Juan Capistrano firm illegally unloaded the material.

Authorities are investigating an Orange County firm for possibly dumping 40 truckloads of sludge illegally at an Imperial County farm instead of at a composting plant.

Kurt Kidman, a San Diego Water Utilities Department spokesman, said Saturday that a city employee had followed a truck operated by Chino-Corona Farms of San Juan Capistrano on April 20 after the agency received an anonymous tip.

Kidman said the Imperial County district attorney’s office as well as regional water quality control agencies are investigating the incident, although no decision to bring formal charges has been made.

“We’re investigating how badly our own contract with the company may have been violated,” Kidman said. He added that the city’s $3-million contract with Chino-Corona Farms has been suspended pending the results of the various investigations.

“We pay them to haul away our non-harmful sludge from our Fiesta Island treatment facility,” Kidman said.

He said authorities have not determined who owns the farm acreage involved and whether the landowner gave permission to Chino-Corona or even knew of the dumping.

“Until now, we’ve been real happy with the work that they do,” Kidman said of Chino-Corona Farms.

Company President Larry Vaughan and his staff were not available for comment on Saturday, but Kidman said they are cooperating in the investigation.

The firm transports sludge for several agencies, including the South East Regional Reclamation Authority and Aliso Water Management Agency, under a no-bid, $410,000 contract involving two Orange County treatment facilities.

Chino-Corona Farms usually sells the treated and dried sludge to firms such as Nurseryland, which then resell the material as fertilizer through retail outlets to consumers, Kidman said.