2025-12-04_REVISION - M2022009 - Laserfiche WebLink

Home Browse Search

CIVIL RES'�URCES Analytes Exceeding Regulatory Limit Well Date Analyte Sample(mg/L) Regulatory Limit(mg/L) PZ-1 8/16/2024 Uranium 0.0284 0.0168 PZ-15 8/16/2024 Uranium 0.0469 0.0168 PZ-15 2/14/2025 Uranium 0.0201 0.0168 PZ-20 8/22/2025 Iron 0.441 0.3 Ten (10)analytes were below the detection limit during each of the five(5)sampling events. Non-Detect Analytes Analyte Detection Limit Aluminum(Al)Dissolved 0.001 ug/L Beryllium(Be)Dissolved 0.0001 ug/L Cadmium(Cd)Dissolved 0.0001 ug/L Chromium(Cr) Dissolved 0.0015 ug/L Lead(Pb) Dissolved 0.0001 ug/L Lithium(Li)Dissolved 0.1 ug/L Nitrite(NO2) 0.15 ug/L Nitrite&Nitrate(NO2+NO3) 0.05 ug/L Mercury(Hg)Dissolved 0.0001 ug/L Silver(Ag)Dissolved 0.0005 ug/L Proposed Changes to the Monitoring Plan • MMMA proposes to increase the reporting limit for uranium by adding one (1) standard deviation of the site- wide mean to the highest observed background concentration at the site. Uranium Site Specific Limit(mg/L Standard Highest Recorded Site Specific Mean Deviation Value Limit 0.0135 0.0093 0.0469 0.0562 • Iron samples have come back as non-detect except for one just above the detection threshold and the exceedance on August 22, 2025 located in PZ-20. The exceedance was measured in PZ-20, which is in the southern end of the Site away from any MMMA associated disturbance. Due to the limited number of measurements for iron,the proximity to offsite disturbances, and the more than five (5)year before MMMA is mining in the southern end of the Site, MMMA proposes to monitor the exceedance in PZ-20 while maintaining the Regulation 41 standard for iron across the rest of the measurement locations. • MMMA proposes to remove the ten (10)analytes that have not been detected at the Site during the baseline period from the sampling list. • MMMA proposes to move to the semi-annual sampling frequency that is outlined in the Groundwater Monitoring and Analysis Plan.