What regulation mandates online turbidimeters in surface water treatment plant filters?

• A. SDSWTR
• B. IESWTR
• C. SWTR
• D. AWT Regulation

Answer: (B)

The regulation that mandates the use of online turbidimeters in surface water treatment plant filters is the Interim Enhanced Surface Water Treatment Rule (IESWTR). This rule was established to address the need for improved treatment practices for surface water sources and to enhance the quality of drinking water. Online turbidimeters are critical because they provide continuous monitoring of turbidity levels, which is an important indicator of water quality and the effectiveness of filtration processes. The rule ensures that treatment systems can quickly respond to turbidity changes, which may indicate problems with the filtration process or contamination.

The other regulations mentioned, such as the Surface Water Treatment Rule (SWTR) and the Stage 1 Disinfectants and Disinfection Byproducts Rule (SDSWTR), do relate to water treatment practices but do not specifically require the installation of online turbidimeters in the same way that IESWTR does. The AWT Regulation is a broader industry guideline and does not pertain specifically to the mandatory use of turbidimeters in surface water treatment.