Derwood is an unincorporated community between Rockville and Gaithersburg, on WSSC Water for water and sewer, with WSSC issuing plumbing and gas permits and Montgomery County handling building permits. 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 Derwood.

Plumbing services in Derwood
Just north of Rockville
Derwood lies north of Rockville and southeast of Gaithersburg, near the Shady Grove Metro, about 16 miles from downtown Washington. It became a census-designated place with the 2010 census and is governed by Montgomery County. MD 200 (the Intercounty Connector), MD 355 and Shady Grove Road border neighborhoods such as Mill Creek Towne, Needwood Estates and Derwood Station, with Lake Needwood and the Redland Shopping Center nearby.
A 1980s neighborhood, mostly
About two-thirds of Derwood's housing went up in the 1980s, the median home dates to 1985, and only around 15% predates 1980. At this age the common jobs are predictable: water heater replacements, failing shutoff and pressure-reducing valves, toilet and faucet rebuilds, garbage disposals, and the occasional pinhole leak. Main drain clogs from roots and grease are also part of the mix as sewer laterals pass the 40-year mark. Finished basements raise the stakes, since a failed sump pump or a burst supply line during a hard freeze can soak carpet and drywall quickly.
Water and sewer
WSSC Water supplies water and collects sewage here. The county Water and Sewer Plan assigns every property a category, so confirm service by address if you are near the edge of development. WSSC's water quality report lists a chlorine residual, UV disinfection at the plants and orthophosphate to slow corrosion. Most of the sewage WSSC collects in Montgomery County is treated at DC Water's Blue Plains plant.
WSSC owns the service line from the main to the property line; the homeowner owns it from the property line to the house. For a break or backup in the street, call WSSC's emergency line at 301-206-4002. WSSC also runs a pipe type program to help you identify the material on your side (pipetype@wsscwater.com).
Permits and backflow
In WSSC territory, a gas water heater, furnace or gas appliance replacement must be done by a plumber or gasfitter holding a WSSC license under a WSSC permit filed through ePermitting (Permit Services, 301-206-4003). WSSC inspects both natural gas and LP gas installations. Building permits are a Montgomery County matter. If your yard has in-ground irrigation, its backflow assembly needs an annual test by a WSSC-certified cross-connection technician.
Gas emergencies
Washington Gas serves Montgomery County. If you smell gas, walk out first, then call 911 and Washington Gas at 844-WASHGAS (844-927-4427), option 1.
What to expect
Share your neighborhood and the symptom. You will be connected with an independent plumber who works in Derwood and nearby Rockville and Gaithersburg, and who agrees on the price and timing with you.
Common questions in Derwood
Where does Derwood's sewage go?
How old are homes in Derwood?
Who owns the water line under my Derwood yard?
Do I need a WSSC permit for a new gas furnace in Derwood?
Nearby cities and towns
Sources
- Wikipedia: Derwood, Maryland
- Point2Homes: Derwood demographics
- Montgomery County DEP: Public water and sewer service
- WSSC Water: Annual Water Quality Report (PDF)
- Wikipedia: Washington Suburban Sanitary Commission
- WSSC Water: Service lines
- WSSC Water: Cross-connection control and backflow testing
- WSSC Water: Plumbing inspections
- Maryland Office of People's Counsel: Your local gas companies
- Washington Gas
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