The subsurface hydrology around Building 9201-2: Results of the July 1994 water level recovery test, Oak Ridge Y-12 plant, Oak Ridge, Tennessee

A water level recovery test was conducted at Building 9201-2 at the Oak Ridge Y-12 Plant in Oak Ridge, Tennessee, from 12:45 p.m. on July 29 until 8:22 a.m. on July 31, 1994. The purpose of the test was to improve the general understanding of the subsurface hydrology around the building. The information is needed to determine the minimum pumping capacity necessary to maintain safe water levels in the basement of the building and to assist in designing systems for treating mercury-bearing waters in the basement. The test was initiated by shutting off the three main sump pumps in Building 9201-2 (i.e., O-12, E-13, and E-22) for 43.5 hr and allowing the water in the basement to approach a static level. The pumps in sumps F-3 and P-6 were also not operating during the test. During the test, water levels were monitored in 5 sumps (P-6, O-12, F-3, E-13, and E-22); a pit near sump K-22; 4 monitoring wells or piezometers in the basement near the O-12 sump, and 16 wells outside of the building. Sump K-22 was dry during the entire test