Helena Water Hardness & Quality Report (2026)

Helena, Montana, the state capital and Lewis and Clark County seat — a major west Montana governmental city (Helena is the Montana state capital — the city grew out of a gold rush camp ('Last Chance Gulch') in 1864 and by the 1880s had become one of the wealthiest per-capita cities in the United States, driven by the fortunes of Montana gold and silver mining; Helena's Victorian-era 'Millionaires' Row' on Rodney Street is a remarkable collection of Gilded Age mansions), home of the Montana State Capitol (a significant Neoclassical capitol building with a notable art collection of C.M. Russell paintings), a diverse Lewis and Clark County community with a primarily governmental, professional, and ranching-heritage population, adjacent to the Missouri River and Gates of the Mountains wilderness area (one of the most dramatic geological gorges in Montana — the Missouri River cliffs named by Lewis and Clark in their 1805 journals), and home of Carroll College — draws its municipal water supply from Tenmile Creek via the Helena Water Division. Water hardness in Helena measures 113 mg/L — classified as moderately hard.

Helena's moderate hardness reflects the west Montana watershed's mixed geology. The Tenmile Creek watershed at Helena–Lewis and Clark County drains the Precambrian Belt Supergroup quartzite (calcareous-poor) and Paleozoic Madison Limestone (calcareous-moderate). Helena Water Division produces the moderate 113 mg/L.

At 113 mg/L, Helena residents encounter moderate scale accumulation. Monthly cleaning is recommended. Helena Water Division consistently delivers water meeting all Montana DEQ and EPA Safe Drinking Water Act requirements.