Lochearn Water Hardness & Quality Report (2026)

Lochearn, Maryland, an unincorporated community in Baltimore County northwest of Baltimore City, receives its municipal water from the Baltimore City Department of Public Works (DPW), which supplies water to both Baltimore City and surrounding county municipalities through regional wholesale agreements. Baltimore City's primary source is Loch Raven Reservoir on the Gunpowder Falls — a major impoundment in the Piedmont uplands northeast of the city — supplemented by the Liberty Reservoir on the North Branch Patapsco River and Prettyboy Reservoir on the North Branch Gunpowder. Water is treated at Montebello Water Treatment Plant and Ashburton Water Treatment Plant before distribution.

The moderate 119.5 mg/L hardness in Lochearn reflects the Baltimore watershed's Piedmont geology. The Gunpowder Falls and Patapsco River drainages traverse the Maryland Piedmont province — a region of Precambrian gneisses, schists, and granitic intrusions interspersed with Cambrian carbonate formations of the Great Valley at the province's western edge. These metamorphic rocks contribute limited calcium and magnesium, while occasional contact with carbonates along the Valley margin moderates overall hardness to the comfortable middle range characteristic of Baltimore's water supply.

At 119.5 mg/L, Lochearn residents have moderately hard water — typical of Baltimore County communities on the city system. Appliance scaling is gradual rather than aggressive: kettles and showerheads develop mineral deposits over months rather than weeks, and glassware may show occasional spots after dishwasher cycles. Quarterly descaling of kettles and coffee machines is sufficient. The primary note for Lochearn residents is the PFAS reading of 6.4 ppt — while below Maryland's proposed action level, residents who prefer extra caution should consider a certified drinking water filter for daily water consumption.