Pumping Test Design, Performance, and Data Analysis

After a well has been sited and design and construction are complete, GGI will design a testing program for the completed well that will: 1) determine well efficiency and specific capacity; 2) determine the long-term, sustainable yield from the well, and; 3) meet the requirements of applicable local and state regulations.

Depending on the project requirements, the testing procedure includes some or all of the following:

Conducting short-term pre-test or step-drawdown test that will be used to determine the pumping rate for a longer duration (generally 48-hour, 96-hour, or 168-hour) constant-rate pumping test.

• Monitoring discharge during the long-term test to maintain a constant discharge rate. Discharge is measured with both an in-line flow meter and a circular-orifice weir to provide redundancy.
• Monitoring water levels manually with a sounder (e-line) for the duration of the test. Where possible, water levels are also monitored with a dedicated transducer to provide data redundancy.
• Monitoring water levels in nearby observation wells.
• Analyzing the test data to determine the long-term sustainable yield of the well and recommend a permanent pump setting.
• Identifying aquifer boundaries (recharge or impermeable boundaries) that may influence sustainable yield.

Discharge from 1230 gallons per minute (gpm) pumping test into lined pond.

Irrigation well testing at a dairy