How many feet of completed main requires one bacteriological sample?

In water distribution systems, regulatory standards dictate that bacteriological samples must be collected to ensure water quality and safety. The requirement for sampling is based on the length of the newly installed or completed water main. According to these guidelines, for every 1,000 feet of completed main, one bacteriological sample is necessary. This is designed to monitor the presence of bacteria and other pathogens that could contaminate the water supply.

By sampling at this specified interval, water systems can effectively evaluate the microbiological quality of the water and ensure compliance with public health standards. This helps in identifying any potential issues early on, allowing for prompt action to resolve contamination concerns before they reach consumers. Sampling less frequently, such as at shorter intervals (e.g., 500 feet), would not adequately assess the entire system's safety or could lead to overlooking potential sources of contamination. Therefore, the correct answer reflects the recommended practice for ensuring water safety in relation to the length of the water main.