What is the capture zone?
A “capture zone” refers to the three-dimensional region that contributes the ground water extracted by one or more wells or drains.
How do you calculate capture zone?
It is calculated by subtracting water level under pumping conditions from the water level without pumping. Cone of Depression is the region where drawdown due to pumping is observed. Capture Zone is the region that contributes the ground water extracted by the extraction well(s).
What is the capture zone of a well?
The capture zone is a 2-dimensional surface that includes the subarea of the total areal recharge providing ground water to a pumped well. The extent of the capture zone boundary can be determined using measurable hydrologic characteristics and simple to complex analytical and numerical models.
What is groundwater capture?
The term capture refers to changes in the flow rates into and out of head-dependent boundaries of an aquifer in response to pumping. In contrast, capture zone refers to the three-dimensional, volumetric portion of a groundwater-flow field that discharges water to a well.
What percentage of water is surface water?
71 percent
About 71 percent of the Earth’s surface is water-covered, and the oceans hold about 96.5 percent of all Earth’s water.
Does groundwater pumping affect streamflow?
Although the benefits of groundwater development are many, groundwater pumping can reduce the flow of water in connected streams and rivers. Groundwater pumping can also draw streamflow into connected aquifers where pumping rates are relatively large or where the locations of pumping are relatively close to a stream.
What are the three types of groundwater?
Groundwater Occurrence and Types of Ground Water
- Rivers.
- Lakes.
- Natural springs.
- Rain.
- Snow.
- Glaciers.
- Aquifers etc.
What is the relationship between groundwater and surface water?
Surface water bodies can gain water from groundwater, or are a source of recharge to groundwater. As a result, withdrawal of water from streams and rivers can deplete groundwater or conversely, the pumping of groundwater can deplete water in streams, rivers, lakes, wetlands, and springs.
How does pumping affect groundwater?
Excessive pumping can lower the groundwater table, and cause wells to no longer be able to reach groundwater. When groundwater is overused, the lakes, streams, and rivers connected to groundwater can also have their supply diminished. Land Subsidence. Land subsidence occurs when there is a loss of support below ground.
How can groundwater depletion affect streams and water quality?
Some of the negative effects of ground-water depletion include increased pumping costs, deterioration of water quality, reduction of water in streams and lakes, or land subsidence. Such effects, while variable, happen to some degree with any ground-water use.
What are the zones of groundwater?
Groundwater is found in two zones. The unsaturated zone, immediately below the land surface, contains water and air in the open spaces, or pores. The saturated zone, a zone in which all the pores and rock fractures are filled with water, underlies the unsaturated zone.
What is capturecapture zone analysis?
Capture zone analysis is the process of evaluating field observations of hydraulic heads and ground-water chemistry to interpret the actual capture zone, and then comparing the interpreted capture zone to a “Target Capture Zone” to determine if capture is sufficient.
Are target capture zones being evaluated effectively at Superfund sites?
An optimization study (U.S. EPA, 2002a) of 20 “Fund-lead” P systems at Superfund sites concluded that capture zones were not being adequately evaluated. At least 14 of the 20 sites did not have a clearly defined Target Capture Zone.
What is the “phased approach” for addressing contaminated groundwater?
This guidance outlines the “phased approach” for addressing contaminated groundwater. The guidance also identifies presumptive technologies for treatment of extracted groundwater, which can be used to streamline the feasibility study for sites that evaluate pump and treat.
What is drawdown in capture zone 28?
of Capture Zone 28 Drawdown is the change of water level due to pumping. It is calculated by subtracting water level under pumping conditions from the water level without pumping. Cone of Depression is the region where drawdown due to pumping is observed.