Entex WavTex System Installed at Carbon Hill, IL to Relieve Overloaded RSF
Carbon Hill is a small village in Grundy County, Illinois, home to 372 residents as of the 2020 census. Like many small communities, its wastewater system had been asked to do more than it was originally built for. The village’s recirculating sand filter (RSF) had been fielding BOD loadings far beyond its design intent, and the filter media was paying the price, clogging faster than it could recover. A network of primary tanks scattered throughout town kept TSS concentrations comparatively low, but organic loading alone was enough to overwhelm the filter. To give the RSF some relief, Entex installed a WavTex™ module in a new pretreatment tank ahead of the filter, tackling the BOD load before it ever reaches the sand.
The system centers on one WavTex module, built with EnTextile media on a stainless steel frame, delivering 4,216 ft² of gross surface area. Since the EnTextile media sheets are buoyant, they don’t take their full shape until the tank fills with water. An integrated coarse bubble aeration grid runs at approximately 100 scfm, doing double duty by supplying treatment air while scouring excess biomass off the media.
Handling a design flow of 0.016 MGD, the module was sized to take on influent BOD as high as 750 mg/L and bring it down to 200 mg/L or lower, while cutting ammonia-nitrogen from an influent of 60 mg/L to an effluent target of 20 mg/L or lower. Installation was completed in November 2025, and with minimal operator attention required going forward, the WavTex module is expected to sustain stable microbiology and treatment performance for 20+ years, easing the burden on Carbon Hill’s RSF for the long haul.
