Our site uses cookies to provide you the best online experience. By continuing to browse, we consider that you accept our cookie policy and agree to the terms of our privacy and terms use. Continue Industry Solutions Products Parts & Services Blogs About Us Contact Us Home Products WWETCO FlexFilter™ System for Primary, Tertiary, and CSO Dual-Use High-Rate Compressible Media Filter: Communities must find a reliable and effective way to prevent weather-related combined sewer overflow (CSO) and sanitary sewer overflow (SSO) from spilling directly into nearby waterways. While a separate treatment system for CSO/SSO concerns is viable for some plants, others do not have the footprint or funding for a single-use system. The WWETCO FlexFilter™ system meets both of these concerns with a simple, gravity-fed process that plants can use for both daily primary or tertiary treatment and sporadic wet-weather treatment to remove total suspended solids (TSS). The FlexFilter system is a high-rate filtration system that uses synthetic compressible media. Media compression is accomplished through the lateral hydraulic force applied by the head pressure of the influent. This unique method of compression eliminates mechanically actuated internal components and provides a tapered media compression. The varied porosity of the compressed media bed allows for increased filtering capacity as well as the ability to treat flow streams with higher solids concentrations – all while minimizing backwash cycles. In addition to the filter's ability to handle higher solids to the filter, the backwash system with air scour and specialized backwash troughs minimizes the volume of backwash water needed. This versatile system has no internal moving parts and is ideal for a variety of applications, including combined sewer overflow (CSO), sanitary sewer overflow (SSO), primary, enhanced primary, and tertiary treatment. It can also function as a dual-use system, providing both primary or tertiary and CSO/SSO treatment. Plants can implement it in both new systems and retrofits. How it works: The influent liquid applies a hydrostatic force to the compression bladder causing the media to compress (1). The tapered compression provides for densely compressed media at the bottom that graduates to an expanded bed toward the surface (2). As the liquid flows onto the top of the media, the larger particles are trapped in the upper portions of the filter. As the liquid works its way down, the smaller particles are captured. This porosity gradient within the filter bed allows for a more effective use of the entire media bed and allows for a higher mass load to the filter prior to backwash (3). As the filter bed becomes plugged, the influent level increases, signaling the need for a backwash (4). For the backwash, the feed to the filter is stopped, allowing the media to decompress (5). The air scour is initiated along with a small amount of backwash water (6). When cleaned, the filter is put back into service or sits empty until the next event occurs. Pilot Program and Mobile/Rental Equipment: We offer multiple pilot and mobile/rental equipment options. For more information, please fill out the Contact Us form. New Jersey Demonstration Project and Report Proves Effectiveness of FlexFilter Cities across the country are struggling to find a reliable and effective way to prevent weather-related stormwater runoff and CSO/SSO from spilling directly into nearby waterways. New Jersey is one state where CSOs are a priority concern. The Environmental Protection Agency (EPA) and New Jersey Department of Environmental Protection (NJDEP) collaborated on The Wet Weather Flow Treatment and Disinfection Demonstration Project. It was conducted over a two-year period, 2014 and 2015, at the Bayonne Municipal Utilities Authority's Oak Street facilities, which receives CSOs from the City of Bayonne. The pilot treatment included high-rate and enhanced high-rate solids removal and disinfection. A total of six technologies were tested in 18 treatment process combinations over nine wet-weather events. Results showed that WWETCO FlexFilter is capable of high performance total suspended solids (TSS) removal (up to 90 percent) and of allowing for disinfection – effluent UV (medium or low pressure) and peracetic acid (PAA). After the demonstration project was complete, the NJDEP summarized the results in a report, with a goal of providing engineering practitioners with an improved understanding of wet-weather treatment technologies and their potential use as satellite end-of-the-pipe wet-weather CSO treatment. Learn more about the New Jersey demonstration project and report on our blog. Primary or Tertiary Treatment Plus CSO: The FlexFilter can easily take the place of a traditional primary clarifier. This creates a dual-use system, providing the additional capacity to handle wet-weather conditions while increasing primary-treatment capacity in dry weather. Likewise, plants that require tertiary treatment can either choose the FlexFilter as their tertiary system or implement FlexFilter as a dual-use system. The FlexFilter can achieve low-level phosphorous removal, helping plants meet increasingly strict phosphorous removal requirements for reuse-quality effluent. Features Gravity-fed passive design Automated operation (requires minimal operator attention) Concrete structure, stainless-steel tank, and retrofit options Compact design that can incorporate screening, disinfection, backwash management, or effluent pumping within the concrete structure Efficient air and low-flow water backwash system Benefits Simple to operate, unmanned operation for CSO/SSO systems No chemical use required for CSO/SSO treatment Rapid, automatic startup with no filter conditioning required No internal moving parts Ability to sit clean and dry between wet weather events Ability to handle high influent solids loading greater than 500 mg/L 80-90 percent TSS removal for CSO and primary treatment Effluent suitable for UV or chemical disinfection Higher loading levels for primary and tertiary treatment due to the unique storage capacity of the fiber media <2 mg/L effluent TSS for tertiary treatment Compact, customizable design supports unique footprints No media loss Applications Treatment for CSOs/SSOs, including unmanned satellite CSO/SSO facilities Stormwater inflow and infiltration (I&I) treatment Enhanced primary filtration for carbon diversion Tertiary treatment and phosphorous removal Dual-use primary or tertiary treatment and CSO/SSO Lagoon effluent Industrial water pretreatment Peak flow management Photos WesTech Newsletter Sign up for the WesTech monthly newsletter to receive content you can use to more effectively design, manage, and maintain your operations. Email* Newsletter Type* - Please Select - Commercial/Industry Newsletter Minerals Newsletter Municipal Water/Wastewater Newsletter Videos WWETCO FlexFilter™ - World's Largest Compressible Media Filter Installation › WWETCO FlexFilter™ - Ohio Stormwater Treatment › WWETCO FlexFilter™ - Operation Timelapse › WWETCO FlexFilter™ - Stormwater Solutions › Literature BROCHURES WWETCO FlexFilter™ High-Rate Compressible Media Filter › Municipal Solutions: Water and Wastewater Treatment › CASE STUDIES Heard County Water Authority - Holistic Approach › Innovative Technology for Stormwater Treatment › Largest Compressible Media Filter in the World › Uptown Park CSO Treatment › Parts & Services Laboratory Services Field Service Preventative Maintenance Drive Retrofits Wear Parts to Stock About Us Who is WesTech? Why Choose WesTech? 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