Maryland Department of Natural Resources

Is Maryland's Groundwater in Jeopardy?

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Critical Questions

These are questions commonly asked about the groundwater resources in Maryland. The answers vary by aquifer and location across the State. Some aquifers and locations likely have a plentiful supply of groundwater of good quality to meet current demands as well as future growth, while groundwater supply in other aquifers and locations may be greatly limited and of poor quality. Answering these questions requires effective monitoring, critical scientific investigations, and a comprehensive regional groundwater-flow and management model.

Why is Groundwater So Important?

Groundwater is nearly the sole source of fresh drinking water in Maryland's Coastal Plain (the area east of I-95). Approximately 2 million people rely on groundwater in the Coastal Plain. While groundwater is not used as much as surface water as a water source, some towns and most domestic users in central and western Maryland also rely heavily on groundwater. A sustainable supply of clean drinking water is crucial to the health and well-being of the citizens of Maryland, in addition to a strong economic future for the State. Aside from being a crucial drinking water source, groundwater is also important for irrigation, commercial and industrial uses, and power plants. Because groundwater supplies water to streams and rivers, it is vitally important for sustaining healthy populations of fish and other aquatic organisms.

water use

Problems Confronting Groundwater Management in Maryland

Groundwater supply in Maryland may be severely constrained in some areas in the future as a result of overuse of the aquifers and by poor water quality. Permitted withdrawals are assessed on an individual permit (well or well field) basis, while there is no systematic assessment of the effects from domestic withdrawals. Currently, the cumulative impact of the many thousands of wells pumping from Maryland's aquifers, or the extent to which the aquifers are being recharged (Coastal Plain region), is not being assessed. Additionally, water-level and water-quality monitoring to evaluate the health of the aquifers is inadequate in some areas.

Problems By Region

Problems confronting groundwater supply in the State varies geographically depending on the number, productivity, water quality and geometry of the aquifers present and the amount of stress the aquifers are under from withdrawals. Some of the major problems or potential problems facing groundwater supply in different regions (or portions of those regions) of the State are listed below.


Central Eastern Shore

Water levels exceeding management levels, well interferences causing conflict between users, salt-water intrusion, arsenic, nitrates, pesticides.

Lower Eastern Shore

Well interferences causing conflict between users, lack of productive aquifers, salt-water intrusion, nitrates, pesticides.

Western Shore

Water levels exceeding management levels, deep pumping levels resulting in high energy costs, lack of productive aquifers, salt-water intrusion, arsenic and radioactivity.

Upper Chesapeake Bay

Well interferences causing conflict between users, water levels exceeding management levels, lack of productive aquifers, salt-water intrusion.

Fractured Rock

Reduction in baseflow to streams threatening aquatic habitat, lack of productive aquifers, arsenic, radioactivity, nitrates, and pesticides.

Possible Consequences

If the current management system continues without the necessary tools and monitoring to effectively evaluate groundwater availability and quality, negative effects may occur, including

  • Well failures (dry holes)
  • High economic costs resulting from shifting pumpage to deeper aquifers or developing alternate water supplies (surface-water reservoirs, desalinization, reclaimed wastewater)
  • Salt-water intrusion
  • Water-use restrictions
  • Land subsidence
  • Loss of stream habitat
  • Degradation of aquatic life
Population and water demand are increasing, placing pressure on Maryland's most precious resource. Growth cannot occur without adequate and reliable water supplies. Every economic sector needs water, and every sector will be impacted if we do not ensure a sustainable resource.

What can be Done to Safeguard the Groundwater Resource?

The Maryland Geological Survey, in cooperation with the U.S. Geological Survey and the Maryland Department of the Environment, began a comprehensive investigation of Maryland's groundwater resources as part of the 2008 Governors Advisory Committee on the Management and Protection of the State’s Water Resources ("Wolman" report) recommendations. The report recommended a more robust water resources program based on sound, comprehensive data, adequate and reliable funding, programmatic and information needs, and implementation of specific legislative, regulatory, and programmatic changes. On the science side, the report recommended establishing a broader and more targeted network of monitoring wells, fully funding major hydrologic studies in both the Coastal Plain and Fractured Rock areas of the State, and improving analytical tools (groundwater-flow models) for predicting the impacts of well withdrawals. The initiative has produced a digital aquifer information system that greatly improves access to critical information. The system is currently used by MDE for assessing water-allocation permits. It is crucial that the full effort be completed so that Maryland can effectively sustain its vital groundwater supplies.