Aquifer: formation (rock), group of formations, or part of a formation that contains sufficient saturated, permeable material to yield significant quantities of water to wells and springs.
Best Management Practices: Practices that decrease or eliminate the likelihood of a potential source of contamination from reaching the groundwater. For example, a permanent crop cover in an agricultural field can reduce the likelihood of storm water runoff from the field contaminating nearby water sources by reducing the sediment, fertilizer and/or pesticide in the storm water runoff.
Karst: A type of landscape that is formed by the dissolution of carbonate and dolomite rocks. Features typical of this landscape are sinkholes, dry valleys, sinking streams, and caves. Groundwater can flow rapidly through the solutional features, resulting in a high risk of contamination due to the rapid infiltration from the surface to the groundwater. Contamination can spread quickly through the groundwater aquifer due to the high hydraulic conductivity of the groundwater flowing through the solutional features.
Hydraulic Conductivity: Measure of the ability of geologic media to transmit water, related in a general manner to pore size and shape.
Land Use Activities (LUA): Land uses that have the potential to adversely impact the groundwater quality are land uses of concern. For example, a gas station in a source water protection area would have the potential to pollute the groundwater if a gasoline storage tank leaked.
Local Advisory Committee (LAC): A committee formed to assist in developing a Wellhead Protection Plan or a Source Water Protection Plan. The Local Advisory Committee can include waterworks employees, town or local government officials, county or regional government representatives, board members, and water customers. The committee examines the potential sources of contamination identified in their Source Water Assessment and determines the source water protection measures that will be implemented.
Potential Source of Contamination (PSC): Specific land uses or materials that are considered “threats” to the public water systems because they have the potential to reach the groundwater source. In a residential area, these PSC’s could be on-site septic systems, sewer lines, heating oil tanks, household, garden, lawn and pool chemicals, and abandoned wells. In an industrial area, the PSC’s could be related to chemical use, storage, and transportation or related to storm water runoff and construction. For agricultural areas, potential “threats” could be chemicals, fertilizers and animal wastes.
Potential Conduit (PC): A preferential pathway for surface water to rapidly reach the groundwater. For example, surface water can enter the groundwater quickly through an abandoned or improperly constructed well.
Public Water Supply (PWS): Public Water Supplies are water systems that provide water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year.
Small Community Public Water Supply: A waterworks which serves at least 15 service connections used by year-round residents or regularly serves at least 25 but not more than 3,300 year-round residents.
Source Water Assessment (SWA): Source water assessment provides information on the potential contaminant threats to surface and groundwater sources that are used to supply public water systems. Each source water assessment consists of a delineation of the source water assessment area, an inventory of land use activities, and a determination of the susceptibility of the water supply to contamination.
Source Water Protection: Actions that protect drinking water sources that serve, or may serve, as public drinking water sources from the threat of contamination as a result of accidents or unwise practices from nearby residential, industrial, commercial, agricultural, waste management or transportation activities.
Source Water Protection Plan (SWPP): A written plan that outlines source water protection measures that will be implemented within a Source Water Protection Area to manage existing potential sources of contamination and to plan to minimize future sources of contamination.
Source Water Protection Area (SWPA): The area contributing to recharge of a well or surface water source. For most wells in central and western Virginia, VDH utilized a fixed radius method of 1000-ft and 1-mile to define the Source Water Protection Areas for each well. The 1000-ft zone is a priority zone for managing potential sources of contamination. The 1-mile zone represents an estimate of the total recharge zone for the well. For surface water sources, the source water protection area generally includes a buffer zone adjacent to the water source and the 5-mile upstream watershed of the water source.
Wellhead Protection: Actions that protect groundwater drinking water sources that serve, or may serve, as public drinking water sources from the threat of contamination as a result of accidents or unwise practices from nearby residential, industrial, commercial, agricultural, waste management or transportation activities.
Wellhead Protection Area (WHPA): The area contributing to recharge of a well. For most wells in central and western Virginia, VDH has used a fixed radius method of 1000-ft and 1-mile to define the Wellhead Protection Areas for each well. The 1000-ft zone is a priority zone for managing potential sources of contamination. The 1-mile zone represents an estimate of the total recharge zone for the well.
Wellhead Protection Plan (WHPP): A written plan that outlines groundwater protection measures that will be implemented within a Source Water Protection Area to manage existing potential sources of contamination and to plan to minimize future sources of contamination. A Wellhead Protection Plan is sometimes referred to as a Source Water Protection Plan.