Guthrie Public Works Authority

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The Guthrie Public Works Authority (Authority) located in Logan County serves 3,280 sewer customers and 3,991 water customers. According to the 2010 U.S Census the population was 10,191.

The Authority’s current treatment process is trickling filter. The design average daily flow is 1.5 MGD, and the receiving waterbody is the Cimarron River which is listed on the 303(d) list for escherichia coli, chloride, selenium, sulfate, total dissolved solids, and enterococcus.

The Authority's wastewater treatment system is in dire need of extensive improvements to enhance its quality and effectiveness. Peak flows were originally calculated based on rainfall data from the period of 2006 - 2016. Additional rainfall data was analyzed for the period of 2016 - 2019 and based on that data the peak-storm flow rate was increased from 6 MGD to 10 MGD, and the pump schedule design was revised to include five pumps. Peak flows consistently cause the wastewater treatment plant (WWTP) to be over or near discharge permit limits.

In order to address the issue, the Authority will construct a new energy efficient sequential batch reactor (SBR) WWTP, lift station, sludge management facilities, UV disinfection system, and lab building.

These improvements will enable to Authority to treat the wastewater more effectively prior to discharging it into the Cimarron River.