The discharge rate from the well is monitored over time. Slug tests can also be done prior to a pumping test to help with the design of the longer, more involved aquifer test.Ī constant-head (or constant-drawdown) test keeps the head (water level) in the control well at the same level throughout the test (maintains the drawdown level). Typically, these tests are much smaller in scale, simpler and shorter than pumping tests, which can last 24 hours or even weeks. Other tests include slug tests and constant-head tests.Ī slug test involves creating a sudden change in water level (water added or removed) and observing the recovery of the well to its original state. Groundwater Level Baseline, Pumping (Drawdown), and Recovery Data From a Pumping Test drawdown and recovery data is then used to estimate hydraulic properties of the aquifer. Pumping tests can be constant rate, or step-drawdown where durations of increasing pumping rates create varying levels of drawdown over time. Drawdown is measured in the pumping well, and also in surrounding monitoring wells, throughout the test period. When the pump is turned off, groundwater levels recover. As pumping occurs, groundwater levels decline (drawdown). Typically, pumping tests are used to estimate hydraulic properties, determine the amount of water available, potential recharge rates, storage potential, maximum withdrawal acceptable, and any impacts on surrounding wells or neighbouring water bodies.ĭuring a pumping test, water is pumped out of a well/bore over a period of time, at a controlled rate. Storativity (storage coefficient): the volume of water released from aquifer storage with a decline in hydraulic head (drawdown). Transmissivity: the rate at which groundwater flows through an aquifer’s entire saturated thickness (or a given unit width). Hydraulic conductivity: a measure of how easily water can move through an aquifer. These tests provide information to determine fundamental aquifer characteristics including hydraulic conductivity, transmissivity, and storativity. In general, water levels, more importantly drawdown levels are monitored during aquifer characterization tests, such as pumping, slug, and constant-head tests. confined, unconfined, leaky, artesian, etc. Different tests are more suited to certain aquifer types, i.e. Each type of aquifer test puts a different stress on the aquifer system and the resulting effects are observed and used to estimate hydraulic properties. Subsurface characteristics can be determined though various aquifer tests.Īn aquifer test is a controlled field test performed on one or more monitoring wells. How do Drawdown Measurements Help Determine Aquifer Hydraulic Properties? Check out our technical bulletin “ Best Practice Low Flow Methods for Highest Quality Samples” for more details. Levelogger Data is Adjusted by Inputing 101D Water Level DrawDown Meter Measurements in the Levelogger Software Data WizardĪpplication Notes: Both 101D Water Level DrawDown Meters and 3001 Leveloggers can also be used to aid low flow sampling (monitor drawdown and help regulate pumping rates) – providing more information for a complete aquifer characterization (aquifer chemistry). These calculations done automatically in the Levelogger Software Data Wizard, instead of another spreadsheet program, saves you time. Manual measurements should be taken when the Levelogger is deployed, periodically during the recording period, and at the end of the monitoring period.Īfter you have downloaded the data from the Levelogger, you can use the depth to water measurements to convert Levelogger pressure readings to depth to water readings or elevation measurements to meet your specific application or model requirements. Using these two instruments together ensures accurate readings and saves you time when dealing with post data processing.Īs a QC check, you can use 101D Water Level DrawDown Meter depth to water measurements to verify the Levelogger is reading correctly. Note: for ease of use when lowering and raising from greater depths, the Solinst 101 Power Winder can be added to a 101D reel. Solinst Model 101D Water Level DrawDown Meter for Manual Depth to Water and Drawdown Measurements
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