East Millcreek Water Hardness & Quality Report (2026)

East Millcreek, Utah, in Salt Lake County — an unincorporated Salt Lake County community on the eastern bench of the Salt Lake Valley, adjacent to Salt Lake City and Holladay, a residential community at the base of the Wasatch Mountains — receives its municipal water from Salt Lake City Department of Public Utilities (SLCDPU) or the Millcreek Township water system, which draws from Big Cottonwood Creek and Little Cottonwood Creek (Wasatch mountain snowmelt streams draining the Big and Little Cottonwood Canyons) supplemented by Metropolitan Water District of Salt Lake and Sandy deliveries.

The moderately hard 165 mg/L hardness and TDS of 346.2 mg/L reflect the Cottonwood Canyon watershed's Wasatch Front geological character. Big Cottonwood and Little Cottonwood Canyons drain the central Wasatch Range — terrain underlain by the Precambrian Big Cottonwood Formation (quartzite and phyllite — soft crystalline) and the overlying Cambrian and Devonian limestone and dolomite thrust sheets of the Wasatch thrust belt. These Paleozoic carbonate formations contribute moderate dissolved calcium and bicarbonate to the snowmelt waters. The Wasatch Front canyons also drain through the Wasatch-Cache National Forest with minimal agricultural or industrial influence, producing relatively clean moderate-hardness mountain water.

At 165 mg/L, East Millcreek's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and bathroom fixtures develop calcium deposits. Quarterly descaling is appropriate. The PFAS level of 2.1 ppt is excellent for the Wasatch Front urban area — significantly lower than the Davis County communities closer to Hill AFB (Clinton UT at 3.6 ppt), reflecting East Millcreek's position in the Salt Lake City supply zone drawing from the pristine Wasatch mountain canyons rather than the Hill AFB-affected Weber River system.