I'll spare you the excrement jokes and just let this idea speak for itself:

Environmental scientists are beginning to use an unsavory new tool -- raw sewage -- to paint an accurate portrait of drug abuse in communities. Like one big, citywide urinalysis, tests at municipal sewage plants in many areas of the United States and Europe, including Los Angeles County, have detected illicit drugs such as cocaine, methamphetamine, heroin and marijuana.

Law enforcement officials have long sought a way to come up with reliable and verifiable calculations of narcotics use, to identify new trends and formulate policies. Surveys, the backbone of drug-use estimates, are only as reliable as the people who answer them. But sewage does not lie. [Los Angeles Times]

Admittedly, assuming the methodology is sound, this appears to be a breakthrough technique for obtaining accurate drug use demographics. And it's already beginning to cast doubt on existing data, not surprisingly to the effect of indicating that drug use has been widely underreported:

The scientists were even able to use sewage to estimate individual use and weekly trends. For instance, they estimated that people in Milan used twice as much cocaine, about 35 grams per person per year, than Italy's government surveys had suggested.

That's kind of neat, I suppose, that they can figure out stuff like that. But ya know what? If our drug policy weren't a raging nightmare, drug testing raw sewage wouldn’t be even remotely necessary. Seriously, the moment the government finds itself digging around in our sewage to figure out what drugs we take, it becomes completely clear that we've screwed up our approach to drugs beyond belief. It shouldn’t even be necessary to formulate arguments as to why this is not the behavior of a healthy society. I mean, really. They're drug testing sewage. What's wrong with them?

All of this is symbolic of the utter lack of information and knowledge about drug use that we've achieved in the course of our abundantly destructive attempts to control this very behavior. Nothing could be easier than determining down to the bottle or butt exactly how many Heinekensâ„¢ or Newport Lightsâ„¢ are consumed by the population, but in order to study marijuana use, we must collect frothing f#%king sewage into test tubes, mix in some noxious chemicals, and run the results through some mindbendingly complex algorithm?

Clueless and reeking of poo, the champions of our failed drug control crusade stand before us straight-faced and swear that everything is going according to plan.