Mapping Drug Use by Testing Sewer Water
I wrote about this in 2007, but there’s new research:
Scientists from Oregon State University, the University of Washington and McGill University partnered with city workers in 96 communities, including Pendleton, Hermiston and Umatilla, to gather samples on one day, March 4, 2008. The scientists then tested the samples for evidence of methamphetamine, cocaine and ecstasy, or MDMA.
Addiction specialists were not surprised by the researchers’ central discovery, that every one of the 96 cities—representing 65 percent of Oregon’s population—had a quantifiable level of methamphetamine in its wastewater.
“This validates what we suspected about methamphetamine use in Oregon,” said Geralyn Brennan, addiction prevention epidemiologist for the Department of Human Services.
Drug researchers previously determined the extent of illicit drug use through mortality records and random surveys, which are not considered entirely reliable. Survey respondents may not accurately recall how much or how often they use illicit drugs and they may not be willing to tell the truth. Surveys also gathered information about large regions of the state, not individual cities.
The data gathered from municipal wastewater, however, are concrete and reveal a detailed snapshot of drug use for that day. Researchers placed cities into ranks based on a drug’s “index load” – average milligrams per person per day.
These techniques can detect drug usage at individual houses. It’s just a matter of where you take your samples.
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Paul Wiedel • July 23, 2009 7:14 AM
This kind of testing really only works at an aggregate level.
Wastewater can be sampled at a house level, but the practice of collecting testable and legally admissible samples would be a tremendous challenge. Collecting samples that would hold up in court would be a logistical nightmare.
Taking a water sample from an individual sewer hook up would logistically be very challenging for most houses. But let’s assume that a house of interest is next to a manhole cover.
Most household wastewater does not contain human waste. It’s mostly waste from showers/dishwashers/laundry, etc. Most of the water that would pass through a sewer hook up would give a negative.
Taking a point sample would likely result in a lot of false negatives.
False positives from contamination is another issue. Sanitary sewers are de facto storm sewers in just about every community. That is to say that there is enough leakage in the sewer that a rainfall will raise the water level in the sewer to contaminate the hook up with traces of waste from other houses. Even ‘clean’ households will have traces of illicit substances.
Letting a sample soak would leave that sample susceptible to contamination from rain or even a blockage in the sewer.
Testing at the plant or at neighborhood sewer lift stations is far more practical than at houses. It also does a decent job of protecting individuals’ privacy.