Towns will shut down pumps for PBAC aquifer check

The six major water users in the Palouse basin will shut down their pumps, likely over the week of Thanksgiving, while University of Idaho researchers take a baseline sampling of groundwater levels in the Grande Ronde aquifer.

The shutdown, expected to be in the range of 48 hours, is being sponsored by the Palouse Basin Aquifer Committee with a University of Idaho team working on the project.

The pump shut-down will include Colfax, Palouse, Moscow, Pullman, Washington State University and the University of Idaho.

Prior to the shut-down, pumps will fill up each entity’s reservoirs to have enough water to meet demand while the pumps are off.

Steve Robischon, PBAC director, said the agencies planned for the Thanksgiving week because the demand on the reservoir supplies will be reduced with a large portion of the college populations out of Moscow and Pullman.

The entities are still coordinating the exact dates and time for taking the pumps off line.

Robischon said the researchers wanted a longer shut-down, but Moscow’s storage capacity cannot meet the demand for much long than that with reservoir levels dropping below requirements for adequate fire flow.

PBAC and the research team anticipate the pump shut-down will allow the team to get a baseline reading of the water level in the Grande Ronde.

Researchers also plan to install new monitoring equipment on the pumps of each town that will give them an hour-by-hour reading. That will give PBAC a better idea of how the aquifer reacts when pumps turn on and off.

Rural residents with wells will not be asked to participate, said Robischon. Rural sites pumps in the area primarily draw water from the shallower Wanapum aquifer.