Earlier this week, the LA Times reported that environmental scientists were testing sewage to get an accurate portrait of drug abuse in major cities around the world.

The results have been intriguing: Methamphetamine levels in sewage are much higher in Las Vegas than in Omaha and Oklahoma City, Okla. Los Angeles County has more cocaine in its sewage than several major European cities. And Londoners apparently are heavier users of heroin than people in cities in Italy and Switzerland.

The White House’s Office of National Drug Control Policy tested the sewage at 100 facilities in 24 jurisdictions under a pilot program in 2006. “Cooperation was very high,” spokeswoman Jennifer de Vallance told me this afternoon. “It was free to the facilities.” The agency mailed out a Nalgene bottle. Each facility filled it up and dropped it in a prepaid FedEx envelope. The test was an experiment to see whether it could produce useful information and the data hasn’t been published.

Usually law-enforcement friendly San Diego, however, refused to participate. To find out why, I put in a call to the Metropolitan Wastewater Department, where a spokesman referred my call to the office of Mayor Jerry Sanders. Still waiting for a call back from Sanders spokesman Bill Harris.