Chicago Plumbing: Licensing, Permits & Water

Two credential systems overlap here by design. The city issues its own Plumber License, Apprentice Plumber License and Plumbing Contractor License (the latter backed by a twenty-thousand-dollar performance bond filed with the City Clerk), with exams run for the Department of Buildings by Continental Testing Services. Illinois state plumber licenses are honored, but only while the employer holds the Chicago contractor credential, and a state-credentialed contractor still needs the city contractor license before working a Chicago address.

• Authority. Board of Plumbing Examiners, through the City of Chicago Department of Buildings; Illinois Department of Public Health plumber licenses are also recognized in the city
• Structure. Chicago issues its own credentials: a single city Plumber License (the city notes it is sometimes called a journeyman license), an Apprentice Plumber License, and a Plumbing Contractor License that carries a twenty-thousand-dollar performance bond filed with the City Clerk; a state IDPH plumber license is valid in Chicago when the employer holds the city contractor credential, and state-credentialed contractors still need the city contractor license to work here
• Worth knowing. Chicago is one of the few US cities running plumber examinations of its own. Applications and exams are administered for the Department of Buildings by Continental Testing Services.

Checked against the official source, September 2026: www.chicago.gov.

The homeowner rule is drawn with Chicago precision: in a detached single-family home, the owner, occupant or even lessee may personally work on the residence's plumbing, code-compliant and inspected, yet may not hire anyone for that work except a contractor holding the city credential. There is no middle ground of handymen. Small like-for-like repairs flow through the web-based Express Permit Program, which replaced the Easy Permit Process in November 2023, without architectural plans; nearly everything else starts with a DOB permit.

• Permit office. City of Chicago Department of Buildings (DOB): plumbing permits are issued as building permits through DOB's permit programs, including the web-based Express Permit Program for small repairs, which replaced the Easy Permit Process in November 2023
• Homeowner rule. One clean exception in an otherwise contractor-only city: the owner, occupant or lessee of a detached single-family home may personally install, alter or repair the plumbing of their own residence, but may not hire anyone except a contractor holding the city credential to do it, and all such work must meet the Chicago Plumbing Code and accept inspection.
• Process. A permit precedes most construction, demolition and repair work in Chicago; small same-kind repair and replacement projects that need no architectural plans go through the web-based Express Permit Program, which replaced the Easy Permit Process on November 6, 2023, and every permitted plumbing job remains subject to inspection.

Checked against the official source, September 2026: www.chicago.gov.

The Department of Water Management's quarterly laboratory analysis puts finished Lake Michigan water at 126 to 146 mg/L of hardness across both purification plants over 2025 and early 2026, averaging 137 mg/L in 2025, the figure used here since the utility publishes no single citywide average. It is textbook moderately-hard-to-hard water: enough mineral to build slow scale in tankless heat exchangers and on fixtures. Chicago's most consequential pipe program is lead: the Lead-Safe Chicago portfolio funds full service-line replacements for income-qualified owners at no cost, waives permit fees for owner-initiated replacements, and, since Illinois law changed in 2023, prohibits partial replacements outright. All of it under the city's own plumbing code, the 2001 edition carrying its 2021 amendments.

• Utility. City of Chicago Department of Water Management (Bureau of Water Supply)
• Supply source. Lake Michigan, drawn through offshore cribs about two miles out in the lake and finished at the Jardine and Sawyer purification plants
• Hardness. 137 mg/L (≈8 gpg), hard; city lab quarterly analysis, 2025 plant outlets 126-143 mg/L, average shown, 2025

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

• Drain Cleaning
• Water Heater Repair

  Lake Michigan water at roughly 126 to 146 mg/L across recent quarters, about 137 on average, builds slow scale, and tankless heat exchangers feel it first.

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

  Partial lead service line replacements are banned in Illinois since 2023: a lead line gets replaced in full, private and public side.

• All services →

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