Why is the Navy continuing to flush drinking water lines?
Please refer to the Red Hill 2023 ACO, Attachment A: Statement of Work – Section 6.5.5 Maintenance Flushing Program (pdf page 63/page 19). Section 6.5.5.2 (pdf page 63/page 19 of the attachment) requires the Navy to develop a Maintenance Flushing Program for EPA approval. Section 6.5.5.3 requires the Navy to implement the Maintenance Flushing Program within 30 days of EPA’s approval of the program (pdf page 64/page 20 of the attachment). EPA approved the Navy’s Maintenance Flushing Program on July 31. 2025.
Part of the Maintenance Flushing Program is to conduct routine flushing. Most public water systems in the United States routinely flush to remove any sediment and scale that may accumulate in the pipes and to maintain water quality throughout the distribution system. For more details on flushing, please refer to the following EPA fact sheet: Protecting Water Quality Through Distribution System Flushing (pdf) .
The Navy plans to flush the entire distribution system as part of the 2023 ACO required implementation from October 2025 to April 2027. Afterwards, the Navy will transition to a five-year rotation for water conservation reasons, in which 20% of the system will be flushed annually until the whole system has been flushed at the end of every five years, pursuant to ACO SOW Section 6.5.5.2 modified on July 8, 2025.
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