One of Clear Water’s best tools for treating sediment-laden or turbid water is chemically enhanced sand filtration, or CESF - but what is it and how does it work?

CESF systems are Active Treatment Systems (ATS) that utilize chemistry as a pre-treatment step. All CESF systems are ATS, but not all ATS systems are CESF. The core treatment chemistry utilized in CESF systems is chitosan, a natural biopolymer derived from the chitin found in crab and shrimp shells. Chitosan acts as a natural coagulant and flocculant, helping to clump suspended particles together. It is not the only chemical utilized in CESF systems, but it is often the most effective and ecologically friendly option.  

When utilized as a pre-treatment, chitosan allows the clumped particulates to be settled out before running the influent water through additional phases of filtration, like sand filters and media vessels. This simple pre-treatment step extends the life of the media and reduces the frequency of backflush cycles and maintenance shutdowns. The remaining smaller, but still clumped, particles that did not settle out in initial treatment phases are more effectively filtered out by the sand and/or media filters, getting to cleaner water, faster.

CESF is effective at removing a wide range of pollutants, including high concentrations of suspended solids, hydrocarbons, and heavy metals. It is considered a cost-effective and environmentally friendly solution for water treatment. Chitosan is a safe, natural product and an excellent tool when high turbidity and suspended solids are present.  

Clear Water’s Active Treatment Systems (ATS) are built and optimized for CESF, featuring automation options that effectively reduce man-hours along with alarm and recirculation functions that ensure proper treatment, safeguarding clients and customers from time-consuming and expensive permit violations and work shutdowns.

These systems can be assembled from our standard components or custom built to fit specific treatment needs or site limitations. We offer a turnkey suite of services to handle water treatment projects from small boat wash systems that fit in a mini container to multi-acre treatment sites that can process millions of gallons of stormwater each rainy season. If you have questions about your project or want to learn more about ATS and CESF systems, reach out to our team at info@clearwaterservices.com.