Reports
Hydrogeology, simulation of ground-water flow, and ground-water quality of the upper Coastal Plain aquifers in Kent County, Maryland
1998, Drummond, D.D.
Report of Investigations 68
Abstract
Ground water is the sole source of drinking water in Kent County and is vulnerable to environmental problems, such as lowered water levels, contamination from agricultural chemicals, and brackish-water intrusion.
Five major aquifers supply ground water to users in Kent County. (p. 6)
- The Columbia aquifer is the shallowest aquifer and extends over most of Kent County. It is used for small domestic supplies. Water levels in the Columbia aquifer vary seasonally, but show no long-term trends.
- The Aquia aquifer underlies the Columbia aquifer in most of the southeastern part of Kent County and is semi-confined in most of that area. Water levels in the Aquia aquifer vary seasonally, but also show a response to pumpage by large ground-water users.
- The Monmouth aquifer underlies the Aquia aquifer and is confined in most of Kent County. It is used for domestic and small commercial supplies in the central part of the county. Water levels in the Monmouth aquifer respond to pump age by nearby large ground-water users, but show very little seasonal or long-term trends.
- The Magothy aquifer underlies the Monmouth aquifer and is used for small commercial and domestic supplies in the northwestern part of Kent County where the Aquia is absent, and for large community supplies elsewhere in the county. Water levels in the Magothy aquifer respond to pumpage by large ground-water users and show a steady decline of about one-half foot per year.
- The Upper Patapsco aquifer underlies the Magothy aquifer and is hydraulically connected to it in parts of Kent County. The two aquifers act as a single hydraulic unit.
Flow-model simulations show that the modest increases in pumpage projected for Kent County will not create significant water-level declines. (p. 32)
- Pumpage scenarios which simulate projected population growth from 1993 to 2012 indicate regional drawdowns of less than 5 feet in all aquifers.
- Pumpage scenarios which simulate projected increases in irrigation pumpage indicate regional drawdowns of as much as 20 feet in the Aquia aquifer and 7 feet in the Magothy and Upper Patapsco aquifers.
Water quality is generally good in all of the major aquifers in Kent County, but each aquifer shows minor water-quality problems. (p. 53)
- The Columbia and Aquia aquifers are vulnerable to brackish-water intrusion and contamination from nitrate and pesticides because they are shallow.
- Water from the Monmouth aquifer has the highest concentrations of radon of any aquifer in Kent County.
- High iron and manganese concentrations cause problems in all five aquifers in Kent County, but they are most severe in the Magothy and Upper Patapsco aquifers. Water from these aquifers is often unusable without treatment.
