City of Wharton Wastewater Treatment Plant No. 2

Although the City of Wharton did not engage Jones & Carter, Inc. to design the existing wastewater treatment plant, we were brought in to provide solutions when persistent permit violations could no longer be tolerated.  We began an in-depth investigation of the system’s customers to determine the source of the permit excursions.  Severe influent concentration spikes were sampled and traced back to discharges that were non-compliant with the city’s pretreatment program. 

The design of the wastewater treatment plant improvements was concentrated on a new basis for influent characteristics that were developed to more accurately reflect the City’s true influent wastewater.  A new elevated headworks was constructed which included a mechanical bar screening and screenings compactor.  The existing 0.5 MGD RBC system was taken off-line and a new extended aeration carrousel was built to replace it.  The added volume and extended detention time provided dilution for spikes and increased treatment for the high COD’s the plant was experiencing.  To save on electrical costs, the city opted for the installation of an automatic aerator control system, which uses dissolved oxygen meters and Variable Frequency Drives to control the amount of oxygen transferred into the system.  By maintaining lower dissolved oxygen concentration during low flows, the city reduced the overall power requirements by 50 percent. 

Also included in this project was flood proofing improvements to reduce the possibility of flooding from nearby Caney Creek, which was identified as a potential hazard in a FEMA grant analysis.  To protect the plant, several options were investigated.  A levee and portable dewatering pump were chosen as the lowest cost alternative that impacted the day-to-day operations the least.  The city now has a dual-purpose pump that it can use for both floodwater removal and dewatering of it’s various construction projects.