Rockville is Montgomery County's seat and runs its own water system for about 70% of the city, while WSSC Water serves the rest. Which provider serves your address decides where plumbing permits come from. Plumber Washington DC Pros is a free referral line, not a plumbing company. Call the number on this page to be connected with a local plumber in Rockville.

Plumbing services in Rockville
The county seat
Rockville was incorporated as a town in 1860 and is now a city with a council-manager government and the Montgomery County seat. It is about 14 miles from downtown Washington and had 67,117 residents in the 2020 Census. Rockville Pike (MD 355), I-270, MD 28 and MD 189 run through it, past the redeveloped Town Center, older neighborhoods like Twinbrook, and Civic Center Park with Glenview Mansion. Biotech, software and federal employers fill the I-270 Technology Corridor here.
Two water systems in one city
This is the main thing that sets Rockville apart. The City of Rockville water system serves about 70% of the city, roughly 13,500 accounts and 54,000 people, with Potomac River water treated at the City's own plant and disinfected with chlorine. The rest of Rockville is on WSSC Water. The City publishes a Water Service Provider Map so you can see which one serves you.
- City-water addresses: the City's emergency line, 240-314-8567, takes sewer backups and water main breaks; the main City number is 240-314-8500.
- WSSC-water addresses: WSSC's Emergency Service Center, 301-206-4002.
On lead, the City says it has finished its service line material inventory, has notified customers, and is responsible for removing lead pipes, while customers share responsibility for lead in home plumbing. In WSSC-served parts, WSSC says it removed all known lead pipe from its distribution system and keeps a service line map.
Permits follow the water provider
Rockville's Express Water Heater Permit Guide spells it out: if WSSC supplies your water, the permit comes from WSSC Water Permit Services (301-206-4003); if the City supplies it, you apply to the City's Department of Community Planning and Development Services (CPDS) online through MGO Connect. A plumber who works here regularly will ask which map area you are in before filing anything. On WSSC addresses, testable backflow assemblies need an annual test by a cross-connection technician holding a WSSC license, with results filed electronically (301-206-4004).
Housing and common calls
The median Rockville home was built in 1980, a blend of postwar subdivisions and newer construction. That mix brings both aging galvanized or copper lines in older sections and water heaters, fixtures and valves reaching the end of their service life in newer ones. Winter freezes and basement water are regular topics.
Gas safety
Washington Gas serves Montgomery County. If you smell gas, go outside first, then call 911 and the Washington Gas Emergency Leak Line at 844-WASHGAS (927-4427), option 1.
Making the call
Have your address handy and, if you know it, whether your water bill comes from the City or WSSC. You will be connected with an independent local plumber who sets the price and schedule with you.
Common questions in Rockville
How do I know if my Rockville home is on City water or WSSC Water?
Where do I get a water heater permit in Rockville?
Who handles a sewer backup in Rockville?
Where does Rockville City water come from?
Nearby cities and towns
Sources
- Wikipedia: Rockville, Maryland
- City of Rockville: Annual Drinking Water Quality Report (PDF)
- City of Rockville: Drinking water quality
- City of Rockville: Express Water Heater Permit Guide (PDF)
- City-Stats: Rockville housing
- WSSC Water: Annual Water Quality Report (PDF)
- WSSC Water: Backflow assembly annual testing reminder (PDF)
- Washington Gas: Safety
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