degree of grouting will most certainly protect the well

degree of grouting will most certainly protect the well from contamination by local surface water.

The second factor to be considered was hydrogeology of the well. More specifically, where was the water being produced in the well bore. From the drillers log, it was found that the well was producing water from two major zones, one near 75 feet and one near 160 feet. Discussions with the geologist involved in the well construction revealed that the majority of the water produced by the well originates from the deeper zone. In any case, both zones are deep enough so that isolation from Rush River should be of a very high degree.

The placement of the well in relation to the local hydrogeologic setting was another important factor to be considered.

Typically in this hydrogeologic setting, ground water originates as precipitation on the mountain sides on both sides of the valley, l^rom there it flows through joints and fractures in the bedrock and through the unconsolidated sediments on the valley sides towards the valley bottom where it emerges as springs both on the surface and right in the river channel. This process occurs through the length of valley, therefore, the stream or in this case, Rush River increases in flow as it moves down the valley. Groundwater is constantly being added to the stream, not the reverse.

Because of the process, groundwater in the valley remains uncontaminated even when Rush River is turned muddy by soil eroding from local hill sides during a heavy rainstorm.

The water supply well for Washington is located very close to Rush River thus it is probably receiving recharge from the valley sides and not from Rush River. This combined with the two previous factors leads me to the conclusion that the introduction of treated water into Rush River will not have an im