Middletown Water Hardness & Quality Report (2026)

Middletown, Delaware, in New Castle County — one of the fastest-growing cities in Delaware, a New Castle County city in the southern Delaware Piedmont-Coastal Plain transition zone, historically a significant fruit and vegetable farming community now rapidly suburbanizing — receives its municipal water from Artesian Water Company or New Castle County utilities, which draws from the Cheswold Aquifer or the Piney Point Aquifer — Eocene-Miocene coastal plain sand aquifers of the Delaware Coastal Plain.

The moderately soft 69.5 mg/L hardness and TDS of 162.4 mg/L reflect the Delaware Coastal Plain aquifer's Eocene-Miocene sand character. The Delaware Coastal Plain aquifer system (the Cheswold, Piney Point, and Aquia aquifer zones) consists of Eocene glauconitic sand and Miocene fine-grained sand and calcareous shell marl deposited in warm Cenozoic shallow-marine environments. These coastal plain sand aquifers have moderate carbonate content from calcareous shell fragments and calcareous cement in the matrix, producing moderately soft to moderately hard water depending on the specific aquifer interval and depth. Middletown's 69.5 mg/L moderately soft reading reflects the relatively low calcium carbonate dissolution in these younger coastal plain sands.

At 69.5 mg/L, Middletown's water is moderately soft — comfortable for household use. Scale forms slowly over many months, soap lathers well, and appliances operate efficiently. Semi-annual descaling is adequate. The PFAS level of 4.6 ppt warrants a certified drinking water filter — the Dover Air Force Base (Delaware's primary military installation — a C-5 Galaxy heavy transport base and AFFF user in the Delaware River basin), and the Delaware Valley industrial corridor's PFAS background contribute to New Castle County's readings.