Local News in Brief : L.A. County Sues Arco

Arco, whose Carson refinery is the biggest user of the county sewer system, has systematically underpaid its bill for four years and owes almost $670,000--the largest amount ever billed an industrial user for shortchanging the sewage system, county officials charged.

The officials, who have been quietly trying to settle the dispute for two years, lost patience with Arco, which has rebuffed demands for payment, and voted Wednesday to file suit against the company. Sewer officials charge that from 1983 to 1986, Arco employees failed to follow the industry’s standard practice of stirring waste water samples when measuring solids--and thereby missed what had settled to the bottom.

Arco on Thursday denied that the company had underpaid its sewer bill and asserted that its sampling used standard procedures, including stirring, and were more accurate than those of sewer officials.

Industrial sewage fees are based, in part, on the amount of solids in waste water, which is an indicator of the difficulty and cost of its processing. Industries conduct their own sampling for solids, then pay the county based on the results. The process is, in effect, an honor system that is subject to audits by the Sanitation Districts of Los Angeles County.