Eric Bradley | January 14, 2018
A construction project required a 25 million gallon lake to be dewatered and discharged into a neighboring pristine lake. Florida law requires discharge to be no more than 29 NTUs over background receiving waters. In this case, the receiving lake averaged 1 to 3 NTUs, so site discharge had to be less than 30 to 32 NTUs. Due to time constraints on the project, the contractor needed to dewater at an average 1,000 gallons per minute (GPM).
Rain was expected, so to minimize the additional water treatment needs and possible delays that rain would create, a lined channel was setup with rock berms and excelsior matting to settle solids and provide passive filtration. The flocculant chosen was HaloKlear Dual Product System (DPS) because of its effectiveness on broad ranging soil types and because of the residual test capability to ensure flocculant was not discharging off-site. The residual kit was able to detect trace amounts of the natural flocculants, far below and levels of aquatic toxicity.
The system ran for two days straight with data collected every 30 minutes during daytime operations. The results were inlet turbidities averaging 542 NTUs and discharge averaging around 13.6 NTUs (recorded), a 97.5% removal average. The project continues to dewater the entire lake successfully with no turbidity violations. The local regulatory agency was so pleased that they have approved numerous dewatering project permits incorporation the same HaloKlear technology.
When it comes to finding innovative solutions for the most challenging wastewater treatment applications, turn to Dober first. Dober’s work, not only as a supplier but also as an innovative customer solutions partner, is why we are the industry leaders in natural coagulant and flocculant technology.