Options For Retrofitting Existing Sand Filters With Pile Cloth Media

Sand filters have long served as a reliable tertiary treatment system in wastewater treatment plants (WWTPs), but over time, they often face declining performance, increased maintenance, and costly repairs. Aging sand filters may suffer from underdrain failures, media loss, backwashing assembly issues, and mechanical problems with traveling bridge systems. Additionally, their large footprint can pose challenges for facilities looking to expand capacity. Replacing or upgrading these systems is often expensive and space-prohibitive. To address these issues, many WWTPs are opting to retrofit existing sand filters with Aqua-Aerobic’s OptiFiber pile cloth media filtration (PCMF) systems. These cloth media filters significantly improve efficiency, reduce operational issues, and increase filtration capacity without requiring additional space. For example, a 20’ x 20’ sand filter with a 400-square-foot filtration area can be retrofitted to achieve over 1,200 square feet of filtration area—tripling throughput within the same footprint. Unlike sand filters, PCMF systems do not require separate backwash water storage, drawing a small amount from the filtered effluent instead, simplifying operation.