NVSWCD Facilitates Soil Survey Update
(Conservation Currents, Northern Virginia Soil and Water Conservation District)
Don’t be alarmed if you see the men pictured here digging holes in the ground in your neighborhood. They’re not archeologists, nor are they developers, but they are looking for clues. David Harper and Garland Robertson are part of a three-member team that is going to complete and update the map of Fairfax County soils. They are both soil scientists from the Natural Resources Conservation Service. (In the photo, each holds an auger, a soil coring device that equally collects soil from the surface through the entire sampling depth.)
The original Fairfax County Soil Survey was published in 1963 by the USDA-Soil Conservation Service. It was based on field work completed in 1955 and covered about 60% of the County. Over the course of the next thirty years, the County’s soil science office transferred the survey to maps that were at the same scale as the County zoning maps and continued to map another 20% of the land scattered throughout the County.
The County soil science office developed a unique numbering system, added new soils, focused on development-related factors, and created the soil problem rating system. However, the County’s survey was never certified to the national standard and incorporated into the National Soil Information System. The soil science office closed in 1996. Approximately 40,000 acres, predominantly in the southeastern part of the County, remain unmapped.
Currently, developers are required to obtain soil surveys when an area is unmapped, but these surveys are not subjected to any quality review to verify they are consistent with national standards.
The Fairfax soil survey update will enable planners, individuals, scientists, farmers, foresters, and anyone involved with land use planning to make smart land use decisions that will work to save money and conserve valuable natural resources.
When most of Fairfax County was mapped and published in 1963, the soil mapping was geared toward agricultural interpretations. Over time, with urban growth and changes in land use, the demand for more detailed soil information has grown.
The soil survey update of Fairfax County is centered on more clearly defining the properties of the soil map unit. The soil survey update will better describe, characterize, and define the properties of the soil components within the existing delineations.
“As a result,” said project leader David Harper, “the soil survey will be a powerful tool to display soil information more accurately while providing information and interpretations not available at the time of the original publication.”
The project involves a unique working arrangement among Fairfax County, the USDA’s Natural Resource Conservation Service, and the Northern Virginia Soil and Water Conservation District.