Maryland Department of Natural Resources


Water quality and temporal variations in chloride concentrations in groundwater in the Maryland Piedmont

2018, VanDerwerker, T.J.

Administrative Report 19-02-01

Key Results

From the early 1970s to the early 2000s the Maryland Geological Survey and the U.S. Geological Survey sampled many wells in the Maryland Piedmont region, testing the water samples for chloride, major ions, and other constituents. These data provide a valuable baseline against which future water-quality samples can be compared to monitor changes in groundwater chemistry. With expanded urbanization of rural areas of the Maryland Piedmont, including increased road-traffic volumes, there is an elevated risk of chloride contamination from road salt and other anthropogenic sources. The purpose of this study is to: (1) assess overall groundwater quality of the Maryland Piedmont; (2) identify sources, concentrations, and temporal variations in chloride concentrations, and (3) determine if elevated concentrations of other chemical constituents (i.e. trace metals and radionuclides) correlate with elevated chloride concentrations.

The groundwater quality of the Maryland Piedmont was evaluated by collecting samples from 25 wells and analyzing for major ions, trace metals, nutrients, radionuclides, and bromide. Wells sampled in the study are on average 177 feet deep with an average casing depth of 37 feet, and completed in 16 different geological formations, including igneous, metamorphic, and sedimentary rock types. Key results from this study are:

Downloads and Data

Administrative Report 19-02-01 (pdf, 3.7 MB)