AWWA WQTC64190

This slide presentation outlines a study on the sustainable removal of micropollutants through riverbank filtration (RBF) and aquifer recharge and recovery (ARR). Aurora's Test Plan for Natural Purification includes: determine the removal of emerging organic micropollutants during RBF and ARR; field-scale studies; laboratory-scale column studies; evaluate fate and transport as well as key removal mechanisms for individual compounds; adsorption vs. biodegradation; and, removal rates under different redox conditions (oxic, anoxic). The RBF Well was Operated and Monitored from December 2004 to June 2006 with these results: TOC, turbidity, nutrients (e.g., nitrogen, phosphate); Organic micropollutants including Pharmaceutical residues (e.g., analgesics, anti-inflammatories, antiepileptics, lipid regulators, antibiotics), personal care products and other trace organics (e.g., antimicrobials, chlorinated flame retardants), endocrine disruptors (e.g., steroid hormones, bisphenol A), and emerging contaminants (e.g., NDMA). Demonstration Testing of Aquifer Recharge and Recovery included: feedwater from RBF site; 25 monitoring wells; 3 nested piezometer wells; 4 production wells; sampling: bulk parameters (TOC, pH, conductivity, nitrate, ammonia), and organic micropollutants (PhACs, Flame Retardants, EDCs, Pesticides). Pilot Scale Soil Column Test Results including Other Acidic Drug Compounds such as Ibuprofen, Naproxen, Diclofenac showed that: no removal was observed under abiotic column experiments; no adsorption onto soil; removal below detection limit under both oxic and anoxic column experiment; and, biodegradation. A summary of RBF and ARR Performance in Aurora's Multiple Barrier Purification System shows that: RBF exhibits consistent removal of TOC, independent from stream flow and season; micropollutants in column experiments were degraded slower under anoxic as compared to oxic conditions; lab-scale findings and field monitoring suggest efficient and sustainable removal of vast majority of micropollutants during RBF; and, findings indicate that NDMA is biodegradable in less than 6 days under anoxic conditions. Includes figures.