Ground-water data in the Harrisburg-Halsey area, central Willamette Valley, Oregon
THE HARRISBURG - HALSEY AREA COVERS ABOUT 350 SQUARE MILES IN THE CENTRAL WILLAMETTE VALLEY , OREG., AND IS PART OF A BROAD ALLUVIAL PLAIN THAT LIES BETWEEN THE CASCADE AND COAST RANGES IN THE CENTRAL PART OF THE WILLAMETTE VALLEY . MOST OF THE DATA FOR THE 506 WELLS IN THIS REPORT WERE OBTAINED FROM WELL DRILLERS' REPORTS. CHEMICAL ANALYSES OF WATER FROM 36 WELLS ARE TABULATED. MOST OF THE HIGH-YIELD WELLS IN THE AREA PRODUCE WATER FROM ALLUVIAL (SAND AND GRAVEL) AQUIFERS THAT UNDERLIE THE VALLEY PLAIN OR THAT ARE COEXTENSIVE WITH THE PRESENT FLOOD PLAIN OF THE WILLAMETTE RIVER. THE WATER TABLE IN THE ALLUVIAL AQUIFER IS GENERALLY ONLY A FEW FEET BELOW LAND SURFACE. PUMPING LIFTS ARE RELATIVELY SMALL, AND WELLS PRODUCE MODERATE TO LARGE QUANTITIES OF GROUNDWATER OF GOOD CHEMICAL QUALITY .