Critical Control Points: Applied Safety Methodology for DPR
(LOS ANGELES, CA – October 4, 2016) – The final report for Water Environment and Reuse Foundation project #13-03 (Critical Control Point Assessment to Quantify Robustness and Reliability of Multiple Treatment Barriers of a DPR Scheme) has been issued.
Funded by the WateReuse Foundation (now Water Environment and Reuse Foundation) and the Metropolitan Water District of Southern California, this project serves as an instrumental step in advancing the acceptance of DPR by demonstrating the robustness and reliability of multiple barriers of treatment to ensure the highest standards of water quality and assure protection of public health. This project was tasked with applying the hazard analysis and critical control point (HACCP) methodology to identify CCPs and assess the reliability of those CCPs to manage acute and chronic health risks in DPR applications. The objective was to identify CCPs and then use full scale operating data from facilities around the world to quantify the ability of those CCPs alone and in series to remove chemical and biological contaminants in potable reuse. An evaluation of process monitors and operational response was also included.
The overall conclusions of this research indicate that both membrane- and non-membrane-based potable reuse systems are capable of managing microbial and chemical contaminants of concern and that the current monitoring and removal credit is highly conservative relative to actual process performance. Through full-scale testing the reseachers were able to validate that when membrane integrity is breached in reverse osmosis and microfiltration membranes, current monitoring systems are able to detect breaches before log removal goals are compromised. As a result of this project, a series of process-specific response procedures were developed to manage alerts (indicating a need for potential corrective action) and alarms (indicating a need for immediate shutdown of a unit process within a facility), providing guidance to design teams and operations teams looking at implementing potable reuse.
Led by Troy Walker and Ben Stanford of Hazen and Sawyer, the research team also included other local and international experts with direct and indirect potable reuse experience. The full report is available on the WE&RF website free to subscribers.