The Test Cells Program was a full-scale field construction and operation project that provided engineers with seepage data for assessing future embankment design and reservoir operation. Barnard constructed two temporary test cells using alternative designs and materials. Together, the cells hold 24 million gallons of water. One test cell includes a cut-off wall inside the embankment to a depth of 30 feet. The owner used a six-week monitoring program to evaluate performance. Construction of the cells required blasting a downstream canal, processing blasted rock with onsite crushing, screening, and washing plants: dewatering and processing embankment fill materials; and tracking seepage with a piezometer/instrumentation package.