PORTLAND — Researchers in Washington and Oregon are working on a novel type of community-wide drug testing. They're studying sewage.

The researchers, from the University of Washington and Oregon State University, are doing testing at 10 sites in Oregon and 10 in Washington to measure the concentration of byproducts of cocaine, Ecstasy and methamphetamine use. They can then estimate the daily drug load per person for each community.

Health officials say it could give social scientists, treatment workers and police a more precise look at drug use trends.

"We could combine it with what we already analyze to give us a better picture of illicit drug abuse," said Karen Wheeler, addictions policy and program administrator for Oregon's Department of Human Services. "It's very promising."

Last year, researchers from the UW, OSU and McGill University conducted a one-day sampling at 96 Oregon sewage treatment plants. Ecstasy showed up in 40 percent of the communities tested, cocaine in 80 percent and meth in all of them, from Oregon's smallest towns to its biggest cities, according to results released earlier this month.

The researchers say that because the sampling was just a snapshot of a single day — March 4, 2008 — it's not statistically valuable to compare the communities' average drug use per person. But their current project will take samples from the 20 Oregon and Washington sites over a yearlong period and should provide more valuable data.

Still, the results of the one-day study are a reminder of the popularity of the three destructive stimulants, said Caleb Banta-Green, a drug epidemiologist at the University of Washington's Alcohol and Drug Abuse Institute and the study's lead author.

"Let's stop trying to pretend it's somebody else's problem or a problem somewhere else," Banta-Green said. "There is drug use in every community."

Detailed results from the one-day study, published in the journal Addiction, showed Portland to be among five communities whose estimated daily use hit the top third for all three drugs. So was Rockaway Beach.

There was no ecstasy or cocaine detected in Garibaldi, on the coast west of Portland, but it fell in the top third for meth. College town Corvallis was in the middle third for all three drugs. Ashland, also a college town, and Pendleton fell in the top third for ecstasy and cocaine.

To make the results of the yearlong study valid, researchers need to make sure that population estimates — key to estimating per person use — are comparable between communities, said Jennifer Field, an Oregon State chemistry professor and one of the study's five authors.

Tourists and commuting workers add complexity, Field said. So do differences in sewage system design.

"We understand the desire to want to discriminate and compare," she said, "but we've got some heavy lifting ahead of us."