Urbanization and Groundwater
(Conservation Currents, Northern Virginia Soil and Water Conservation District)
Groundwater is accumulated water under the earth’s surface. Sometimes groundwater is close to the surface; sometimes it is very deep. Groundwater can surface—or discharge—through natural means, such as in a spring, or with human help, such as in a pumped well.
Groundwater is replenished—or recharged—through surface water seeping from streams or lakes into the ground or through precipitation percolating into the ground. For the groundwater table to stay at the same level, the amount of recharge must equal the amount of discharge.
Urbanization poses a threat to our groundwater supply in several ways. Urban development increases the amount of impervious (nonporous) surface in a watershed. Impervious surface inhibits groundwater recharge because precipitation cannot penetrate the surface. As a result, groundwater is depleted.
Urbanization also increases the amount of pollution in our environment. If soil is contaminated or surface runoff is polluted, the quality of the groundwater will be affected. Polluted groundwater and/or a diminished supply of groundwater are of particular concern where groundwater is the major source for drinking and irrigation water.
How can you help protect our groundwater?
- Don’t pour toxic or hazardous waste down the drain, into a toilet, on the ground, or into storm drains.
- Properly dispose of litter and pet waste.
- Don’t dump anything into a sinkhole.
- Don’t use or store fertilizers, pesticides, gasoline or any toxic materials near a well.
- Pump out septic tanks regularly.
- Use porous material such as flagstone, gravel, stone, or interlocking pavers rather than asphalt or concrete.
- Conserve water in your home and landscape.
Further information about groundwater protection is available from the Virginia Department of Environmental Quality, while groundwater location information is available from the U. S. Geological Survey. For concerns about possible groundwater contamination, please call the Division of Environmental Health at the Fairfax County Health Department at 703-246-2205, TTY 703-591-6435.