Ham Lake Water Hardness & Quality Report (2026)

Ham Lake, Minnesota, in Anoka County — an Anoka County city adjacent to Andover and Blaine in the north Twin Cities metro — receives its municipal water from the Ham Lake Water Division, drawing from the Mississippi River (Anoka County) or local groundwater through the north Twin Cities distribution system.

The moderately hard 141 mg/L hardness and TDS of 263.8 mg/L reflect the north Twin Cities metropolitan area's moderate carbonate watershed character — consistent with the Minnesota River system and the Minneapolis-adjacent communities. The Mississippi River at Anoka County drains the Minnesota Till Plain — Ordovician Prairie du Chien Dolomite (calcareous — the primary Minnesota carbonate platform), Cambrian Jordan Sandstone (calcareous cement), and calcareous Pleistocene Des Moines Lobe till. The Prairie du Chien dolomite and Cambrian calcareous formations produce the moderately hard north Twin Cities supply.

At 141 mg/L, Ham Lake's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 4.4 ppt warrants a certified drinking water filter — the Anoka County north Twin Cities suburban corridor and the Minnesota PFAS background from the 3M Cottage Grove plant (the major Twin Cities PFAS source — contaminating the Mississippi River via the South Washington County groundwater plume) contribute to Ham Lake's readings.