Repiping in Mount Rainier, MD

Mount Rainier's older homes

Mount Rainier is an early 1900s streetcar suburb right on the DC line, with many Sears kit houses and Craftsman homes, and a large part of town is a National Register historic district. Homes of that age often have galvanized steel supply pipe, cast iron drains and older sewer laterals. Galvanized pipe rusts from the inside, so it narrows over time and produces rusty water and weak flow long before it leaks. Many houses also have a mix of galvanized and copper from repairs over the years. Where steel meets copper without the right fitting, the joint can corrode faster than either pipe, so those transitions are a common leak point. Replacing the whole system removes them all at once, and it is often paired with a check of the old drain lines, which in homes this age can be cast iron.

WSSC Water supplies the city, not DC Water. WSSC publishes a lookup map showing service line material by address, including lines marked lead, galvanized requiring replacement or unknown. WSSC's tap water testing puts Potomac plant water at about 140 mg/L hardness on average and Patuxent plant water at about 65 mg/L.

Plumbing permits come from WSSC, which requires a plumber holding its license for interior re-piping. The city's Code Compliance Department issues city building permits, and some permits come from Prince George's County, so the plumber should confirm what the project needs.

Staged or all at once

Signs to watch for

• Rusty or brown water when taps first open
• Low flow, especially upstairs
• Leaks at threaded joints
• Pressure that drops when two fixtures run

Timing

Older homes often have pipe in exterior walls or unheated areas, so winter cold can turn a weak spot into a split. If the system is already failing, plan the repipe before the coldest weather. Plaster walls and historic trim also take more time to open and restore, so allow extra scheduling time for older houses.