Area towns pump 2.6 million gallons, up 3.1%

Municipal pumpers pulled more water out of area aquifers last year, but pumping remains well below levels of 20 years ago.

Steve Robischon, director of the Palouse Basin Aquifer Committee, reported at the Palouse Basin Water Summit last week that 2.6 million gallons of water werepumped out of the shallow Wanapum and deeper Grand Ronde aquifers in 2011.

That’s enough to fill an area the size of four football fields as tall as the Lewiston Grade, Robischon told the crowd at the University Inn-Best Western in Moscow.

That total pumped by the municipal water systems in Colfax, Palouse, Pullman, Moscow, the University of Idaho and Washington State University represents a 3.1 percent increase over 2010 pumping.

Robischon noted the total is still 16 percent less water than was pumped in 1992, when the regional Ground Water Management Plan was put into effect by local agencies. For perspective, he added the area’s population has increased nearly 17 percent in that same time.

Colfax pumping was down six-tenths of a percent, while Pullman pumping rose 1.4 percent.

While conservation measures have lowered demand on the aquifers, groundwater levels are still dropping by almost a foot a year.

That is especially important as samples have shown the Grand Ronde is not being recharged.

Samples from the deeper basin show little trace of tritium, an indicator that reveals “new water.” Atomic tests during World War II released tritium into the area. Samples from the Wanapum aquifer contain the element, while those from the Grand Ronde do not.

Moscow is the only city that pumps from the upper aquifer and has had five wells go dry over the past five years.

Robischon stressed the importance of further conservation and research to preserve the region’s water supply.

Last year, PBAC was awarded a $300,000 grant from the Washington state Department of Ecology to better define the boundaries, depth and recharge zones of the region’s aquifers. The grant will allow PBAC to drill monitoring wells outside the known limits of the aquifers.