Addressing the concerns a client had with receiving a new finished water quality in their distribution system, and how this change in water quality might impact their water and wastewater treatment facilities and operations.

By Matt Ridens, CH2M HILL Associate Engineer

Matt Ridens will present the poster “Consecutive Distribution Systems as a Water Supply Solution to Serving Denver South Metro Utilities”  on Monday, June 10 from 2-5:00 p.m., during the American Water Works Association’s Annual Conference and Exposition (ACE 13), in Denver, Colorado. Learn more about CH2M HILL’s ACE 13 2013 participation and technical sessions.

I began my career with CH2M HILL in 2007 after graduating from the University of Colorado. Over the past 6 years I have gained experience in water treatment, wastewater treatment, greenhouse gas emissions, and dynamic simulation for hydraulics and water quality. This will be my first time attending AWWA ACE and I am very excited to attend such an important event for our industry.

I will be presenting a poster on Monday, June 10 during the Water Quality and Research Poster Session from 2-5 PM. The poster is titled “Consecutive Distribution Systems as a Water Supply Solution to Serving Denver South Metro Utilities” and was created by myself and my co-authors Jason Curl, CH2M HILL, and our client Charlie Krogh of the Pinery Water & Wastewater District in Colorado. Pinery is currently operating on groundwater supplies and is looking to diversify their water sources. Our client is a member agency of the South Metro Water Supply Authority (SMWSA). A partnership between SMWSA and Aurora Water will provide member agencies with finished water from Aurora’s new treatment facility, the Peter Binney Water Purification Facility. The focus of this presentation is to discuss the concerns our client had with receiving a new finished water quality in their distribution system, and how this change in water quality might impact their water and wastewater treatment facilities and operations.

Aurora Water operates with chloramines as their disinfectant in the distribution system, while Pinery currently operates with free chlorine for disinfection. Converting from chloramines to free chlorine through breakpoint chlorination poses the potential for increased Disinfection Byproduct (DBP) formation. An initial desktop study showed the theoretical DBP formation was close to the EPA Maximum Contaminant Levels (MCL) for total trihalomethanes (TTHMs) and haloacetic acids (HAA5). Because of this, bench-scale testing was pursued as a partnership between Pinery and Aurora Water to better understand DBP formation potential. The initial bench scale testing showed that Pinery would be able to use breakpoint chlorinated water in their distribution system with a sufficient chlorine residual and DBPs below their respective MCLs much past the expected water age seen in summer months.

This issue will become more common with Front Range communities and across the United States as more utilities move away from diminishing ground water supplies and diversify their water sources. This partnership among utilities provides a more sustainable water source for the future while utilizing new treatment infrastructure to benefit many agencies in the south Denver metro area. I encourage anyone who wants to learn more to attend the poster session on June 10, or to contact us for more information. Thank you, and I look forward to seeing you at ACE 2013!