Ilchester Water Hardness & Quality Report (2026)

Howard County Department of Public Works — Bureau of Utilities serves Ilchester, Maryland, providing water to over 100,000 residents across Howard County. The primary source is surface water from the Liberty Reservoir on the Patapsco River, supplemented by groundwater from local wells. Water is treated at the Patuxent Filtration Plant and several smaller facilities, ensuring distribution through an extensive network monitored at over 150 locations. The utility tests for more than 150 parameters and publishes annual water quality reports to confirm compliance with EPA Safe Drinking Water Act standards.

The Patapsco River watershed flows through Piedmont and Coastal Plain physiographic provinces underlain by limestone, chalk, and sedimentary rock formations. These dissolve calcium and magnesium as water percolates, yielding a moderately hard supply. Carbonate-rich aquifers of marine origin — including calcite, aragonite, and magnesium calcite from weathered shell material — shape the mineralized character of the water and contribute to the moderate hardness level characteristic of central Maryland.

At moderate hardness, scale buildup develops on fixtures, shower stalls, kettles, and inside appliances such as water heaters and dishwashers, reducing efficiency and shortening lifespan. Soap lather efficiency is reduced, and residue accumulates on surfaces. Regular descaling with vinegar, installing polyphosphate filters, or using an ion-exchange softener is recommended to protect plumbing and appliances. The 2023 CCR confirms PFAS compounds were tested and all results were below regulatory limits; treatment includes filtration, disinfection with chlorine, and fluoridation, with corrosion control maintaining compliance with lead and copper rules.