Every drop of Riverton’s culinary water comes from the Jordan Valley Water Conservancy District, so the hardness at a Riverton tap is the district’s: a 2025 average of 182.4 mg/L, or about 10.7 gpg. That’s just over the line the USGS uses for “very hard” water. For most tankless heaters in Riverton, a yearly flush keeps ahead of it.
Why Riverton’s number is the district’s number
Riverton’s Water Conservation and Efficiency Element says Jordan Valley provides 100% of the city’s culinary water. Riverton itself doesn’t publish a hardness figure we could verify, so this page uses the district’s 2025 water quality report and says so.
That’s not a shortcut. When a city buys all of its water from one wholesaler, the wholesaler’s report describes what comes out of the tap. The district’s annual average does blend many sources and months, though. Its 2025 samples ranged from 16.0–381 mg/L, so the water reaching a Riverton home on a given day can sit well above or below the average. The grains-per-gallon figure on this page is a conversion of the district’s mg/L average, which is why it reads as an approximation.
The well water Riverton walked away from
Riverton didn’t always buy all its water. In 2015, it stopped using its wells for culinary water and switched to Jordan Valley water after residents complained that the well water was too hard and tasted bad, as KUTV reported.
The wells are still there. The city’s water element says Riverton has six deep wells, but five of them aren’t used because of water quality concerns. The city’s own planning document names Jordan Valley as the source of all its culinary water.
For a tankless owner, that history is useful context. By residents’ own account, the well water they rejected was harder than what the city delivers now. If the city ever brings wells back into culinary use, it would be worth re-testing your tap and checking the city’s water report, because the hardness at your heater could change.
Jordan Valley water and the manuals
At about 10.7 gpg, Riverton’s water lands between the brands:
| Brand group | Limit | Riverton’s average |
|---|---|---|
| Takagi and A.O. Smith | 7 gpg | Over |
| Bosch | 100 ppm | Over |
| Rinnai and Rheem | 200 ppm | Under, but close |
| Navien and Noritz | 12 gpg | Under, but close |
“Under, but close” is the honest summary for Navien, Noritz, Rinnai and Rheem. The district’s average sits just past the start of the USGS “very hard” range, more than 180 mg/L, and the sample range goes well higher. A Navien or Rinnai owner in Riverton is under the published limit on an average day and should still flush every year.
What’s typical in Riverton homes
The USGS notes that hard water can cause mineral buildup in plumbing, fixtures, and water heaters, and in a tankless heater that buildup collects in the narrow passages of the heat exchanger. The supply story is the local detail that matters. Every Riverton home is on the same wholesale water, so a flush schedule that works for one house is a fair starting point for its neighbors. That’s different from cities that blend their own wells with district water.
The district’s water comes mainly from reservoirs. Jordan Valley says about twenty percent of its supply is groundwater from wells around the valley, with most of the rest from Provo River reservoirs.
What a flush involves on a Rinnai
On moderate water like Riverton’s, doing the flush yourself can look tempting. Rinnai’s SENSEI manual gives a sense of the job. It calls for four gallons of undiluted, food-grade white vinegar, circulated by a pump at four gallons per minute for 60 minutes, followed by a fresh-water rinse of 5 minutes. The procedure also says to remove and clean the in-line filter at the cold water inlet.
None of that is exotic, but it needs isolation valves, a pump and hoses, and HomeGuide prices a DIY flush kit at $100–$300. It also carries risk: Rinnai’s manual says damage caused by lime build-up is not covered, so scale damage from a skipped or incomplete flush falls on the owner. Our DIY vs professional guide covers when each makes sense.
Services for Riverton tankless owners
- Flush and descale: the yearly job on Jordan Valley water.
- Annual maintenance: the flush plus the parts a flush alone doesn’t cover, such as venting and the condensate line.
- Repair: when a code, cold water or a burner problem needs diagnosis.
- Installation: new units, replacements and conversions.
- Scale prevention: mostly for Takagi, A.O. Smith and Bosch owners, who are over their limits here.
Cost guides put a professional flush in the $150–$250 range, per Angi. A DIY kit is an option for some owners; our cost guide compares the two.