Commercial Plumbing in Denver

Colorado's Primary Drinking Water Regulations (Regulation 11, section 11.39) require public water suppliers to control cross-connections, and suppliers carry that out through cross-connection control programs. Under those programs, backflow prevention assemblies are tested when installed and annually after that by a credentialed cross-connection control technician, with test reports sent to the water provider.

Denver Water surveys commercial service lines, fire lines, dedicated irrigation lines and multifamily service lines. Its program notes that reduced pressure (RP) assemblies are required for most commercial and industrial uses, and that it can suspend service where a required assembly hasn't been installed or tested. Aurora Water, Colorado Springs Utilities, Fort Collins Utilities and other providers run their own programs with their own forms and deadlines.

What property managers should keep on file:

• The location and type of each assembly (domestic, fire, irrigation)
• The most recent test report and the next due date
• Contact information for the tester who handles the building

In Denver, food service operations outside single-family and duplex buildings need a grease interceptor, and its design is reviewed with the building permit through the city's Sewer Use and Drainage Permit process. Denver's published guidance includes several details worth knowing before a remodel or lease:

• Kitchen, food prep and ware-washing dishwashers must discharge through the interceptor; bar dishwashers in beverage service areas may not connect to it.
• Changes in ownership, menu, process, seating or equipment can trigger review, and an existing interceptor may need inspection for condition and size.
• Ejector pumps aren't allowed upstream of an interceptor, and a shared interceptor must be sized for every space it serves.

Suburban sewer utilities run their own programs; South Platte Renew, for example, publishes requirements for food service establishments in its service area.

On the plumbing side, kitchen lines downstream of sinks and dishwashers still build up grease between interceptor pumpings. Regular drain cleaning of those lines, scheduled outside service hours, keeps a backup from closing the kitchen. Interceptor pumping itself is handled by a grease hauler.

Each kind of building wears its plumbing differently, which changes what to inspect and when.

Water heater replacement deserves advance planning in Denver. For existing commercial and multifamily buildings, the city's energy code can require an Electrification Feasibility Report before a gas water heater is replaced, with electrification required when that report shows it's cost-effective. Like-for-like replacements that qualify for a Quick Permit, which since September 2026 includes many commercial water heaters under 200 MBH, are exempt. Replacing a unit before it fails leaves time to sort this out. Our water heater repair and installation page covers the equipment side.

The biggest variable in commercial plumbing is how much of the building has to go without water. Older buildings often lack isolation valves on branch lines, so a small repair can mean a building-wide shutdown. Adding valves during the first repair makes every later one smaller. After any shutdown, expect air and loosened sediment in the lines; aerators and flush valves catch that debris, so they get checked before we leave.

Before a scheduled visit, a property manager can help by:

1. Identifying the main shutoff and any branch or floor valves, with keys to mechanical rooms.
2. Sending tenant notice with the shutoff window and a contact name.
3. Pulling as-built drawings, if any exist, and recent backflow and interceptor records.
4. Clearing access to ceiling panels, cleanouts and water heater closets.

For leaks inside walls or under slabs, see leak repair. Recurring backups from the building's main line usually point to the sewer lateral, covered under sewer line repair.