The Surface Water Treatment Rule requires that disinfectant residuals be collected at the same location in the distribution system as?

The Surface Water Treatment Rule mandates that disinfectant residuals must be collected at the same locations in the distribution system where coliform samples are taken. This requirement is crucial because it ensures that the disinfectant levels in the water supply correlate with the potential for biological contamination, specifically regarding coliform bacteria.

Coliform bacteria are an indicator of the general sanitary quality of water, and their presence suggests possible contamination with fecal material. By collecting disinfectant residual samples at the same points as coliform samples, operators can monitor the effectiveness of the disinfection process in real-time and ensure that the water remains safe for consumption. This relationship emphasizes the importance of maintaining appropriate disinfectant levels throughout the distribution system to prevent microbial contamination.

The other types of samples mentioned, such as those tested for E. coli, lead, and nitrates, are important for ensuring water quality as well, but they do not directly relate to the monitoring of disinfectant residuals in the same way that coliform sampling does within the framework of the Surface Water Treatment Rule.