Xylem has launched the 9210p on-line TOC (total organic carbon) analyzer for routine monitoring and regulatory compliance reporting in drinking water. The 9210p provides real-time data and visibility of natural organic matter that reacts to form harmful disinfection byproducts. All public water systems must comply with U.S. EPA regulations by Oct. 1.
The U.S. EPA has issued two rules regulating levels of disinfectants and disinfection byproducts in drinking water. The Stage 1 Disinfectants and Disinfection Byproducts Rule (D/DBPR) took effect in 2002, lowering the permissible levels of THMs to 80 mg/L and regulated levels for five HAAs, bromate and chlorite in drinking water for the first time. The Stage 2 D/DBPR was promulgated in 2006. Compliance dates for the Stage 2 D/DBPR are phased in over time based upon the number of people served by the water system.
On-line TOC monitoring can provide plant operators a dynamic, real-time view of natural organic matter (NOM) levels in water to adjust and control the coagulation, flocculation, and disinfection steps to minimize formation of disinfection by-products. Data from an on-line TOC analyzer may also be used for D/DBPR compliance reporting provided the analyses are performed in accordance with the sample oxidation, detection, calibration, and QC verification criteria in U.S. EPA approved methods 415.3 or SM 5310C.
