Louisville runs a city-owned water and sewer utility with two water treatment plants, and the City's Building Safety Division permits and inspects plumbing. Plumber Denver CO connects callers with independent plumbers and does not do the work itself. Call the number on this page to be connected with a local plumber in Louisville.

Plumbing services in Louisville
Southeastern Boulder County, 18 miles from Denver
Louisville is a home rule city in Boulder County, incorporated in 1882 and counted at 21,226 people in 2020. Its center is about 18 miles from downtown Denver as the crow flies, with Boulder the closest larger city. What began as a coal-mining town is now a residential suburb with a historic downtown along Main Street and roughly 32 miles of trails. US-36, CO-42 and the Northwest Parkway are the main routes. Hundreds of homes were rebuilt after the December 2021 Marshall Fire, so the housing mix includes newer construction alongside the older streets near downtown.
A city water system fed by South Boulder Creek
Louisville Public Works owns the water utility and runs two treatment plants. The supply is surface water from South Boulder Creek, stored in Marshall Lake, Harper Lake or Louisville Reservoir, plus water from the Colorado River basin. The City disinfects with chlorine rather than chloramine. Very few homes rely on private wells, since the municipal system serves the city. The City keeps an inventory of water service lines to confirm no customers are on lead lines, and customers whose service line material is unknown are asked to report it. Results for each year are in the City's annual water quality report.
Sewer and who to call for a backup
Wastewater goes to the City's own treatment plant on the east side of town, which uses UV disinfection and discharges to Coal Creek; some of the treated effluent irrigates parks and a golf course. If sewage is backing up, the City wants to hear about it: the Public Works Operations Division answers at (303) 335-4750 on weekdays from 7 a.m. to 3:30 p.m., and its on-call line after 3:30 p.m. is (303) 489-2301. Calling the City helps sort out whether the problem is in the main or in your own line, which is where a plumber comes in.
Permits and backflow testing
The Building Safety Division at City Hall, 749 Main Street, first floor (303-335-4584), issues permits through its online portal and performs plumbing inspections along with building, electrical and mechanical ones. Backflow is handled through the City's contractor, Backflow Solutions, Inc. Certified testers file their reports with BSI, and property owners with questions can reach BSI at 888-966-6050.
Gas leaks and Xcel Energy
Xcel Energy provides natural gas in the Louisville and Superior area. A rotten-egg smell means everyone should leave the house right away. From outside, call 911 and then Xcel's gas emergency line at 1-800-895-2999.
Compared with Denver
A Louisville homeowner deals with City water treated on its own plants instead of Denver Water, a city-run sewer instead of Denver Wastewater Management, and Louisville Building Safety for permits. Winters behave the same way, with deep freezes and dry air that can split hose bibs and crack lines in unheated spaces. When you call the number on this page, explain the problem and whether you have shut off the main valve, and you will be connected with an independent plumber who works in Louisville. That plumber sets the price and schedule with you directly.
Common questions in Louisville
Does Louisville use chloramine in its water?
Who do I call about a sewer backup in Louisville?
How are backflow tests filed in Louisville?
Who issues plumbing permits in Louisville?
Nearby cities and towns
Sources
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