The City of Black Hawk's Water Department supplies the entire city from two of its own treatment plants, and our research didn't find a published backflow program, so ask the Water Department what applies. For an assembly that needs testing, repair or replacement, call the number on this page to be connected with a local plumber in Black Hawk.

Black Hawk's water system
Black Hawk is a former gold-mining town turned casino town along North Clear Creek. The City's Water Department supplies drinking water to the whole city, residents and visitors alike, from two treatment plants: Dory Hill, which uses membrane filtration on North Clear Creek water, and Hidden Valley on Clear Creek near I-70 east of Idaho Springs. Water from Hidden Valley travels about seven miles through three pump stations, over a summit about 1,800 feet above the plant, then by gravity to a million-gallon tank on Miners Road. The City adds soda ash for corrosion control and disinfects with chlorine gas.
We didn't find a backflow program in our research. Casinos, hotels and restaurants are exactly the kind of connections utilities usually protect, so ask the Water Superintendent at (303) 582-2246 what's required.
What to do now
- Call the Water Department. Ask about testing rules and reporting.
- List assemblies. Note each one's location, size and last test.
- Clear access. Mechanical rooms and vaults should be open for the visit.
- Stop leaks. Close the isolation valve on a leaking device if safe.
Symptoms and likely causes
| Symptom | Likely cause |
|---|---|
| Relief valve discharging on an RP | Pressure swings or a fouled check |
| Failed test on a large assembly | Worn rubber or springs |
| Pressure drop to a building | Clogged strainer or partly closed valve |
| Cracked outdoor device | Freeze at high elevation |
What affects cost
- Assembly size. Large commercial and fire line assemblies take longer.
- Number of devices. Big buildings may have several.
- Repairs and retests. Parts plus a second test.
- Access. Tight mechanical spaces add time.
- Permits. The City contracts SAFEbuilt for Building Division services; questions go to [email protected].
Pressure swings are one common cause of relief valve discharge on reduced pressure assemblies, so note when a discharge happens, such as when equipment starts or at certain times of day, and tell the plumber. Black Hawk's mountain setting means long winters, so any outdoor device needs draining before the cold arrives.
Building engineers can make the visit faster by having a list of each assembly with its make, size and serial number, and by arranging any needed water shutdown in advance. Testing a domestic assembly briefly interrupts water to the building, so plan around guests and kitchens.
Backflow Testing questions in Black Hawk
How often does a backflow assembly need to be tested here?
Why is my backflow preventer dumping water from its relief port?
Does a home fire sprinkler or boiler change the backflow rules?
Is a permit needed to add or replace a backflow preventer?
More plumbing services in Black Hawk
Backflow Testing nearby
Helpful guides
Sources
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