Can You Meet Numeric Turbidity Discharge Limits?
State and federal regulations are becoming more stringent to combat the negative impacts of sediment and other contaminants that enter our water resources via erosion, stormwater, and dewatering. Sediment that is transported following erosion caused by land disturbing activities is one of the most prolific causes of pollution in our water resources. Strengthened erosion, sediment, stormwater and dewatering regulations may limit the turbidity of discharge waters to ensure our nation’s waters stay clean and clear for drinking, bathing, fishing, swimming, aquatic organisms, and for environmental sustainability for generations to come.
Numeric discharge limits can greatly improve the quality of runoff water but can be difficult or even impossible to meet with traditional BMPs in the presence of clays, silts, and other small particles. Chemical treatments options, in the form of flocculants and coagulants are often needed to successfully remove fine colloidal particles that do not readily settle and are too small to be captured. The addition of chemical treatments in conjunction with traditional BMPs allows for the reduction of 95+ percent of turbidity from discharge waters. Proper training and use of chemical treatments is vital to ensure safe and effective use. All flocculants and coagulants are not the same, with varying charges, composition, uses, and associated toxicity. Correct flocculant selection is needed to ensure optimal turbidity reduction while maintaining safety for aquatic organisms. This presentation will discuss how to select the safest, most effective chemical treatments available to achieve compliance with strict numeric discharge limits. It will also introduce the use of flocculants in conjunction with conventional BMPs to make them work more efficiently.
Author Bio
Brian Free is a Certified Professional in Erosion & Sediment Control (CPESC), Certified Professional in Storm Water Quality (CPSWQ), Qualified SWPPP Developer/Practitioner (QSD/P), and a Certified Professional Agronomist (CPAg). Brian brings a holistic approach to solving many of today’s challenges in erosion control and stormwater management. He has successfully helped clients in many market segments including energy, transportation, homebuilding, solid waste management, mining reclamation, and post-fire remediation.
