Tourism measurement device. (Photo by Davin Tarr)

Last weekend, temperatures and heat indicies that soared above 100 sent hundreds of thousands clamoring toward the beach. In Ocean City, Md., officials recorded some 267,500 people in town, WAMU reports.

But how did they come up with that figure? As WAMU reports, it wasn’t from combing the beach or counting the fares collected on the Bay Bridge. It came from measuring the amount of wastewater collected at a treatment plant in a system called Demo Flush. The system records the sink drainage, shower runoff and toilet water of every hotel room, residential bathroom and public commode and filters the numbers through a complex formula to determine the number of people visiting the beachside community.

It all sounds pretty funny, measuring tourism through sewage levels, but to Ocean City Public Works Director Hal Adkins, it’s no joke. Adkins tells WAMU that Demo Flush is outdated, arbitrary and severely flawed:

What the current formula is, is you take the daily wastewater flow. They are subtracting from that, 570,000 gallons right off the top. Once you’ve taken that away from the daily wastewater flow, they then divide that by 36.04. One would question, where does the 36.04 come from? That was the end result of a series of numbers and calculations that I really don’t want to get into right now that compared the day tripper to the year-round resident to the restaurant flows to the residential flows.

Adkins says that the Demo Flush equation dates back to 1971, and hasn’t really been revised since. For that reason, he’d like to do away with it entirely. Unfortunately for Ocean City, though, Adkins says he doesn’t have a good replacement.

“[A]s much as I don’t like the Demo Flush number, I don’t know of a better alternative,” Adkins tells WAMU.

At the very least, perhaps next time you’re in Ocean City, do Adkins a solid and only flush once. Not only will it save water, it’ll also prevent you from running up the score on Ocean City’s tourist measurements.