Creating Consistency and Optimizing Operations
Hazen provides unique turnkey solutions for a water treatment plant in Georgia to comply with LCR revisions
The Cobb County-Marietta Water Authority (CCMWA) approached Hazen to optimize corrosion control to reduce copper pitting in homes receiving drinking water from two of their water treatment plants (WTPs). Although operations at the utilities had largely remained in compliance with regulations, there was the need to implement proactive measures in light of the 2021 revisions to the Lead and Copper Rule.
Hazen was enlisted to audit and evaluate the current measures used by CCMWA, provide a viable strategy that would reduce pitting of copper pipe while complying with the latest U.S. Environmental Protection Agency guidelines -- including the LCR revisions -- and incorporate industry best practices. The main challenge was to ensure that corrosion control measures did not increase lead levels and water quality was maintained.
To accommodate the client’s needs an implementation plan was developed, which provided recommendations on treatment alternatives to improve corrosion control as well as training for CCMWA staff on system operations and management.
Project Outcomes and Benefits
- Identified corrosion control treatment
- Conducted geospatial analysis of distribution system
- Performed water treatment process evaluation
- Identified strategies to improve process control in finished water pH consistency
- Developed loop testing plan and constructed and operated two pipe loop systems
Mitigating Copper Pitting and Optimizing Corrosion Control
Hazen identified corrosion control treatment alternatives to minimize lead release into drinking water and reduce the potential for copper pitting corrosion. Once the client identified their preferred alternative treatments, additional pipe testing was also carried out to cover alkalinity/Dissolved Inorganic Carbon (DIC) adjustment, and phosphate inhibitors.
Results from the pipe loop studies revealed that the use of phosphoric acid reduced the potential for copper pitting and provided optimal corrosion control to reduce lead leaching into drinking water. Approval from the Georgia Environmental Protection Agency was obtained for the full-scale implementation of phosphoric acid for corrosion control at both of CCMWA’s treatment facilities.