Rockville’s Water Remains Safe
Treatment Plant Upgrades Help Ensure Reliability
June 30, 2026
Rockville’s drinking water once again met or exceeded all federal water quality regulation limits, according to the city’s annual Drinking Water Quality Report.
The city’s water system serves 70% of Rockville, or approximately 13,500 accounts and 54,000 community members. The Washington Suburban Sanitary Commission serves the remainder of the city.
At Rockville’s Potomac River water treatment plant, operators monitor water quality to ensure compliance, disinfection and corrosion control, helping prevent lead and copper in service lines and household plumbing pipes from leaching into drinking water.
Upgrades completed at the plant in the past year include replacing chlorine gas with sodium hypochlorite, or liquid chlorine, and replacing components that provide primary disinfection in the treatment process.
The improvements will enhance system reliability, provide safer workspaces for employees and improve community safety because sodium hypochlorite does not carry the same immediate, catastrophic inhalation risks as chlorine gas.
The plant will continue to improve with the upcoming replacement of aged sludge dewatering equipment from 1995 and clarifier improvements from 1957.
The city is also developing a water treatment plant facility master plan to comprehensively assess systems and equipment at the plant, determine the need for and prioritization of future projects, and identify upgrades needed to treat emerging contaminants in the water system.
In compliance with federal lead and copper requirements, Rockville completed and submitted its initial lead service-line inventory to the Maryland Department of the Environment by the October 2024 deadline. The city also notified all customers required to receive notification by November 2024.
Due to an administrative oversight, the city submitted its formal certification of notification to MDE on Sept. 24, 2025, after the July 1, 2025, deadline. The late filing resulted in a reporting violation.
The delay involved administrative documentation and did not affect water quality or public health. Customers were notified in accordance with federal regulations. The city has since updated its compliance tracking procedures to help ensure future documentation is submitted on schedule.
View the report and interactive service-line map, and learn more about the city’s ongoing efforts to comply with federal lead and copper requirements, at rockvillemd.gov/lcrr.
Find the annual report detailing the source and quality of Rockville’s drinking water at rockvillemd.gov/water.