Frederick requires backflow assemblies on commercial, industrial, domestic, irrigation and fire lines, each tested at installation and every year, and irrigation generally needs a reduced pressure assembly. Water comes from the Town east of I-25 and Left Hand Water District west of it, while St. Vrain Sanitation District handles sewer. Call the number on this page to be connected with a local plumber in Frederick.

When a Frederick business should call
- A notice that your annual backflow test report hasn't reached the Town
- An irrigation backflow device that sprays or drips when the system starts in spring
- Drains in a kitchen, salon or shop that slow down week after week
- Several fixtures backing up at once
- A water heater that leaks or can't keep up
- Toilets and urinals that keep running
Utilities and rules in Frederick
Three entities supply water inside town limits. Everything east of I-25 is on Town of Frederick water, Left Hand Water District serves west of I-25 and Central Weld County Water District serves part of town. The Town's water is Colorado-Big Thompson supply from Carter Lake, plus Town-owned Windy Gap units, treated under agreement at Central Weld's Carter Lake Filter Plant and disinfected with chlorine. The Town has inventoried its service lines and will share the inventory on request.
St. Vrain Sanitation District handles sewer for Frederick, Firestone, Dacono and parts of Mead. It treats the building sewer line as the property owner's responsibility and keeps staff on a 24-hour line for backups at 303-776-9570.
The Town's Engineering Department runs a cross-connection program under state rules. Commercial, industrial, domestic, irrigation and fire lines all require backflow assemblies and annual testing, and irrigation generally needs a reduced pressure (RP) assembly, since double checks aren't allowed. Test reports go to the Town and to Aqua Backflow. Questions go to 720-382-5807.
Permits come from the Town Building Department at 401 Locust Street, with inspections by Town staff or its partner CAA. On permits that require a state-credentialed plumber, inspectors may verify the plumber's identity and can fail an inspection until that's done, so the person named on the permit should be reachable.
Cost considerations
- Converting an irrigation double check to an RP assembly to meet Town rules
- Repairs needed before a backflow device can pass its yearly test
- Clearing and inspecting a building sewer line that the owner is responsible for
- Fixture count, building size and access
- Permits, inspections and off-hours scheduling
What to expect from the call
You'll be connected with an independent local plumber who handles commercial jobs in Frederick. Describe the property and the problem, mention whether you're east or west of I-25 and have any backflow notice nearby. Gas in Frederick is Black Hills Energy; if anyone smells gas, leave first, then call 911 and Black Hills using the number on the gas bill.
Commercial Plumbing questions in Frederick
Do fire sprinkler and irrigation services need their own backflow protection?
How do we find out which water or sewer district serves our building?
Who is responsible for the sewer line from our building to the main?
Which office issues plumbing permits for a commercial property?
More plumbing services in Frederick
Commercial Plumbing nearby
Helpful guides
Sources
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