Since 1998, the United States Environmental Protection Agency developed several new regulations to reduce the risk of biological contamination while limiting the risk from disinfecting chemicals and their byproducts. The Area Wide Optimization Program (AWOP) was developed to help water systems meet successively more stringent regulations and achieve higher levels of water quality.
AWOP is a joint program between the EPA and states, and North Carolina has participated in AWOP since 2000. North Carolina works cooperatively with water systems to use existing equipment and treatment processes to improve or optimize water quality.
Initially, AWOP focused on comprehensive performance evaluations (CPE). Water systems that fail to meet turbidity performance criteria are required to perform a detailed review of treatment processes and practices. Several surface water systems in North Carolina have voluntarily participated in the CPE process in order to improve plant operations. Target turbidity levels are 0.1 NTU, well below the regulatory limit of 0.3 NTU. Water treatment plants that consistently achieve such a low level of turbidity achieve significant water quality benefits.
The next phase of AWOP is performance-based training (PBT). Performance-based testing joins water systems and state representatives together for hands-on training sessions. Small groups practice plant management and laboratory procedures, and learn ways to better use existing equipment. Performance-based testing sessions typically consists of five or six sessions where water system representatives study their own plants for homework assignments. The sessions focus on ways to use existing knowledge and equipment and challenge each person to improve some treatment process at his own plant. Participants in PBT sessions can expect to further develop investigative, reporting and presentation skills as well as become more familiar with other water treatment professionals in the area.
In order to meet both disinfection byproducts regulations and microbial removal requirements, many surface water plants must carefully control their multiple barrier treatment processes, including source water selection and protection, coagulation, sedimentation, filtration and disinfection as well as managing water age and consistency in the distribution system. Performance-based testing may also provide a valuable way for water plants to learn disinfection byproducts control techniques. By actively participating and by developing special studies, water plant representatives can learn how to control these compounds while still meeting microbial removal requirements.
The Ground Water Rule was published in late 2006. This regulation imposes new microbial removal requirements on some groundwater systems. The EPA is currently developing an AWOP pilot program to work with groundwater systems. North Carolina looks forward to the results of the pilot program and may adopt new techniques with groundwater systems.