Investigation of Practical Issues Associated with Dichlor/Trichlor Disinfection.

Over the past six months, the TSC optimization team has collaborated with researchers from ORD to investigate monitoring interferences and implications for water systems that use chlorinated isocyanurates (also known as “dichlor/trichlor”) as a disinfectant; there is currently no approved method for measuring this disinfectant residual. Interferences with various EPA-approved free chlorine methods (DPD, indophenol, amperometric electrode) were evaluated, disinfectant residual stability and regulated DBP formation were compared, and a water chemistry model for dichlor/trichlor was updated to include temperature dependence.  Results from this investigation will be used to support OGWDW technical guidance to SDWA primacy agencies that oversee water systems using dichlor/trichlor as a disinfectant. Preliminary results were presented at the AWWA WQTC and TSC expects to jointly author a peer-reviewed journal article with ORD.  (Matthew Alexander and Alison Dugan, U.S. EPA Technical Support Center).

Region 6/7 Area-Wide Optimization Program.

The TSC optimization team, in partnership with EPA Regions 6 and 7, led a program implementation meeting October 24-26, 2017, in New Orleans, LA.  Representatives from Arkansas, Iowa, Kansas, Louisiana, Missouri, New Mexico, and Oklahoma attended.  The states provided updates on their optimization efforts and highlighted performance data and impacts of their programs on public health protection. The event included a technical training workshop about a disinfectant byproduct (DBP) surrogate method that may be useful as a process monitoring tool at water systems challenged by DBP formation. Discussion covered a range of topics, including: approaches to integrate data integrity review into sanitary surveys; optimizing chlorine residual in distribution systems; implementing an AWOP awards program; and integrating optimization concepts into operator certification.  (Matthew Alexander, U.S. EPA Technical Support Center).

2017 AWOP National Meeting Cincinnati, OH | August 8-9, 2017

The U. S. Environmental Protection Agency (EPA) partnered with the Association of State Drinking Water Administrators (ASDWA) to host the seventh biennial Area-Wide Optimization Program (AWOP) National Meeting in Cincinnati, OH on August 8-9, 2017. This meeting also recognized the 20th anniversary of the AWOP.  The meeting is a venue for participating states and EPA regions in the AWOP network to foster networking, share program implementation strategies, successes, challenges and lessons-learned, and to discuss strategies for building, strengthening and maintaining an effective area-wide optimization network. The meeting is also an opportunity for states that are interested in the AWOP to learn about the program and understand the path to implementing an AWOP in their state.

Over one hundred participated in the meeting, including 27 via remote access during the presentations.  Thirty state drinking water programs were represented, in addition to ASDWA, AWWA (Partnership for Safe Water), US EPA (4 Regional Offices, OGWDW and ORD) and PAI (EPA’s small business contractor supporting the optimization program).  Representatives of the City of Rockhill, SC and Mobile, AL also attended and provided case histories of water quality improvements resulting from AWOP implementation. Additional organizations implementing and/or interested in wastewater optimization programs were also represented at the meeting.  These included the Ontario Ministry of the Environment and Climate Change, Haldimand County (Ontario), the Grand River Conservation Authority (GRCA), located in Ontario, and the GRCA’s small business contractor supporting its watershed-wide wastewater optimization program.

Throughout the course of the two-day meeting, speakers shared perspectives on AWOP and participating states and EPA regions provided summaries of their optimization programs. Three interactive workshop sessions were conducted. The first workshop focused on developing status components, including case study presentations from Washington and Iowa and a workshop on improving individual filter effluent data integrity.  The next workshop topic addressed targeted performance improvement, with case studies from South Carolina and Alabama that included presentations from water treatment plant operators in those states.  The last workshop covered program maintenance and self-assessment, including a case study from Kentucky. Small group breakout discussions focused on a variety of topics including optimization for harmful algal blooms, data integrity, optimization for corrosion control, operator certification, Distribution System Optimization, AWOP integration, potential roles for Technical Assistance providers, and membrane optimization.

The AWOP National Meeting is a great opportunity for program participants to meet in person to share information, celebrate achievements and discuss lessons-learned on program implementation, tracking performance, and addressing unique drinking water quality challenges faced by states and water systems.  The variety of discussion platforms, including interactive workshops, panel discussions, small-group discussions and pre-planned presentations, allowed for effective networking and information sharing among participants. The National Optimization Leadership Team (NOLT) has reviewed and will incorporate participant feedback and lessons-learned from the meeting to improve program effectiveness and help address ongoing and future optimization challenges.

For additional information about the 2017 AWOP National Meeting, presentation and workshop materials, state and regional reports, and small group feedback, please go to the following:

  • U.S. EPA AWOP SharePoint site (in the AWOP Meeting document library):,

  • ASDWA AWOP Webpage for presentation recordings: