Tourist-measuring wastewater 'flush index' skewed due to rogue dumper
Park City has two ways to keep track of tourists. The Park City Chamber Bureau looks at a sampling of lodging numbers. The other way, the so-called “flush index,” looks at how much human waste is processed monthly at the local sewage plant. For the first time, those numbers didn’t match. An investigation revealed a dangerous dump of organic matter is to blame.
The flush index is based on historical wastewater flows measured by the Snyderville Basin Water Reclamation District. The district calculates a monthly report for the purpose of estimating the number of visitors that were present in the Park City area.
The methodology to figure out the number of visitors in town involves a statistical model that considers the quantity of wastewater, the strength of wastewater, monthly visitation patterns and restaurant use as well as an adjustment for rain or snow melt seeping into the system.
For the month of March, the visitation numbers provided by the sewer district show almost a 19% increase compared to the same time last year. But that’s way off what the chamber reported for the same time frame. According to the chamber’s CEO Jennifer Wesselhoff, the lodging numbers for March are down 5% from a year ago.
“This is the first time that Mike [Luers'] flush index and our occupancy numbers weren't necessarily in alignment,” Wesselhoff said. “Generally, the numbers that we report and the numbers that he reports are within points of each other. So, when we heard that report, we thought, gosh, I think we need to go back and reconcile and see maybe what that difference is for March.”
Given the discrepancy, water reclamation general manager Mike Luers went back to the original report and found that on March 2, three times the normal amount of organic waste flooded the treatment plant. At the time though, it wasn’t noticed.
“So, we just kind of missed that one high date because it's so unusual,” Luers said. “Basically, someone put something in the system that was extraordinary.”
What got put into the system, they don’t know. At this point, they won’t know unless someone steps up to accept responsibility. The district requires permits for any large discharges into the wastewater system. That wasn’t done in this case. Luers said, luckily, it was a disaster diverted.
“If someone were to dump enough organic material in our system, they could kill our system," Luers said. "Because the organic material uses oxygen in the treatment plant and if we were to receive so much organic material, we wouldn't have enough oxygen to keep our biological organisms alive. It could technically, and practically, destroy our treatment plant. This is serious. That's why anything stronger than domestic wastewater, other than a restaurant, you know, I'm talking about the manufacturing-type stuff and big food or food-like operations, you know, breweries, distilleries, they’re all permitted with us. And we have limits on how much they can give us.”
He said, going forward, they will be watching. And if need be, he said they will put samplers in the system.
“We keep our eyes open. And, you know, if it happens again, it's just like a detective situation where every time it happens, you gain a little bit more information," Luers said. "And if that happens on a regular basis, we will put samplers out throughout the system to narrow down where it's coming from. And, you know, we know how to do that. We've done that before. But it doesn't happen very often. Thank goodness.”
Once the numbers from March 2 were taken out, he said the numbers looked a lot closer to what the chamber originally reported but were still off by about 4%.
Meanwhile he said the district has received a lot of feedback from customers who have connected sump pumps. He said district employees are happy to come out and inspect residential sump pumps to ensure that they are not connected to the sewer system.
Luers says they found one home that had four sump pumps connected to the wastewater system, which would be close to 250,000 gallons a day from that one home, if they ran all day. He said too much runoff water getting into the wastewater system could create a similar situation to March 2, killing off the biological organisms that break down the waste.