Repository and Pond 4 Sample Clauses

Repository and Pond 4. ‌ Monthly, quarterly, and annual inspections of the repository ensure that remedy controls remain intact and the waste remains isolated from the environment. Inspection observations and maintenance activities for the quarter consist of the following: • No area of the repository cover showed settling, slumping, fracturing, seepage, ponding, or significant erosion. • No anomalous surface feature conditions were observed at the disposal cell or Pond 4. Surveillance checklists for this quarter are attached as Appendix A. No further minor burrowing by voles and small ground squirrels was observed this quarter on the disposal cell and Pond 4 berm. • The disposal cell LCRS and LDS were operated in accordance with the requirements specified in the LTS&M Plan. Findings for the disposal cell LCRS and LDS this quarter include the following: ⎯ Leachate production from the disposal cell was approximately 710 gallons per week combined for sumps LCRS 1 and LCRS 2. There is no action level for the disposal cell LCRS. See Appendix B for a graphical depiction of leachate production history. ⎯ The disposal cell LDS continues to receive no water; therefore, the disposal cell LDS action level was not exceeded. See Appendix B for a graphical depiction of leachate production history. • Operation of the OU III GRO system resulted in increased water collection in the Pond 4 LCRS. Pond 4 LCRS and LDS action levels, approved by EPA and UDEQ, were formally developed in the Repository and Pond 4 Groundwater Contingency Plan-Final (DOE 1998) and are also found in Appendix D, Section 5.0 of the LTS&M Plan. The leakage rate action level established for the Pond 4 LCRS is 851 gallons per acre per day (gpad) (2000 gallons per day), and the leakage rate action level for the LDS is 20 gpad (47 gallons per day), which is averaged over a 7-day period. These leakage rates are based on the area of the floor of Pond 4, which is 2.35 acres. Currently, the LCRS and LDS monitoring and pumping systems are functioning as designed to recirculate water back into Pond 4. U.S. Department of Energy Monticello NPL Sites FFA Quarterly Report: Oct. 1–Dec. 31, 2022 Doc. No. 43572 • Findings for the Pond 4 LCRS and LDS for this period are as follows: ⎯ Water collection at the Pond 4 LCRS continued but did not exceed the action level this quarter (see Appendix B) ⎯ Water collection in the Pond 4 LDS remained below the action level (see Appendix B)