Baltimore Plumbing: Licensing, Permits & Water

Maryland's State Board of Plumbing licenses the trade; Baltimore's DHCD adds an administrative gate with a clever lock: contractors register in ePermits with an active license on file, and when a homeowner names a plumber on an application, the permit hangs at Pending Authorization until that plumber personally approves the use of their license. Nobody gets attached to a Baltimore permit without their own consent on record.

• Authority. Maryland State Board of Plumbing (Department of Labor) statewide; Baltimore's Department of Housing & Community Development keeps a trade-contractor registration in its ePermits system, though the city issues no plumbing license of its own
• Structure. The state board licenses masters, journeymen and apprentices; the city's layer is administrative but real: any contractor added to a Baltimore permit must be registered in ePermits with an active license on file with the DHCD trades unit
• Worth knowing. When a homeowner files a permit and names a plumber, the application shows Pending Authorization until that contractor personally approves the use of their license on the permit, a built-in check against borrowed credentials.

Checked against the official source, September 2026: dhcd.baltimorecity.gov.

The homeowner boundary is drawn in the city's own FAQ: general construction on your own property, yes. Plumbing, electrical, gas and HVAC, no, each requiring a contractor credentialed in that discipline. The mechanics run through ePermits: any change, installation or replacement of a plumbing system is permit work, the trade inspectors schedule against the permit, and the clock is six months to expiration, or three on a condemned property.

• Permit office. Department of Housing & Community Development (DHCD); permits are processed online through the ePermits system, with fees payable at the One-Stop Permit Center on Fayette Street
• Homeowner rule. No: Baltimore's FAQ is explicit that a homeowner can perform construction and alteration work on their own property with a few exceptions, and plumbing, electrical, gas and HVAC are the exceptions; each of those trades requires a contractor credentialed in that discipline.
• Process. Changing, installing or replacing any plumbing system needs a permit; every permit requires inspections scheduled with the trade inspectors; and an ePermits permit expires six months after issue, or three months if the property is listed as condemned.

Checked against the official source, September 2026: dhcd.baltimorecity.gov.

DPW's certified laboratories at Montebello and Ashburton publish mineral analyses month by month, and the most recent posted year, 2021, averages 110 mg/L at Montebello and 78 at Ashburton, moderately hard reservoir water by the utility's own lab reporting. The figure shown here is the Montebello plant average. Scale is a background process here. The active project is underground: the Baltimore Service Line Partnership, mailing letters from fall 2025 to homes with known or predicted lead or galvanized lines, with a self-report survey for everyone unsure of their material. City code adopts the 2021 International Plumbing Code with Baltimore modifications.

• Utility. Baltimore City Department of Public Works (DPW), Bureau of Water & Wastewater, serving about 1.8 million customers regionally
• Supply source. Three city-owned reservoirs (Liberty, Loch Raven and Prettyboy, some 84 billion gallons of storage), treated at the Ashburton and Montebello plants, with the Susquehanna River held as a drought reserve
• Hardness. 110 mg/L (≈6.4 gpg), moderately hard; utility report, 2021

Utility information: www.baltimorecity.gov. The hardness figure is the same record shown on the Maryland page.

• Drain Cleaning
• Water Heater Repair

  DPW's own labs put Baltimore water at 78-110 mg/L by plant, which means moderate scale on the utility's lab numbers.

• Sewer Line Repair
• Septic Tank Pumping
• Leak Detection & Repair

  The Baltimore Service Line Partnership mails letters to homes with known or predicted lead lines from fall 2025. Unsure homes can self-report their material online.

• All services →

This page explains how plumbing is regulated in Baltimore; it is not a provider directory. For the job itself, describe the problem and your ZIP: a license-checked plumber who covers Baltimore gets the details and contacts you with next steps and a quote.