Laserfiche WebLink
Exhibit 1 <br /> 5. Routine quarterly sampling of GVMW-25 began in Q4 of 2018. Quarterly <br /> reports from Q4 2018 through Q2 2021 showed no increases of any constituents, with the <br /> exception of two reported readings for sulfate in August and September 2019. <br /> 6. Beginning with samples collected from GVMW-25 as part of the Q3 2021 <br /> sampling event, concentrations increased for several analyte, including Beryllium, <br /> Cadmium, Fluoride, Manganese, pH,Sulfate and Zinc. At that time,CC&V stated in the Q3 <br /> 2021 Groundwater Surface Water Monitoring Report, the increases were due to large <br /> precipitation events causing a flushing effect, which increased the ECOSA seep discharge <br /> volume and lead to another seep expressing approximately 1,000 feet northwest of the first <br /> seep. <br /> 7. As a result of the increased concentrations, the Division required monthly <br /> monitoring of GVMW-25 to determine if conditions would return to Q2 2021 conditions, <br /> considered to be representative of baseline conditions. <br /> 8. In October 2021,most analytes appeared to have recovered to baseline conditions <br /> until August 2022 when analyte concentrations again began to increase. There have been <br /> additional increases in concentrations in readings at GVMW-25 since August 2022. <br /> 9. Due to the trend of increasing concentrations, the Division continued to focus on <br /> data received from GVMW-25. The Division concluded that ongoing monitoring within Grassy <br /> Valley has demonstrated there are impacts to groundwater on-site. No off-site impacts have <br /> occurred. <br /> 10. The September 2023 Grassy Valley Monitoring Report from CC&V included <br /> results from samples collected from OSABH-17, located near the northeast corner of the ECOSA. <br /> Increased concentrations at this well were detected prior to those detected in GVMW-25. <br /> 11. Because this well is not part of the monitoring plan and is not a point of <br /> compliance well, CC&V did not notify the Division of these increased concentrations or <br /> immediately provide the data collected from OSABH-17. Furthermore, the Division concluded <br /> based on the most recent sampling event,April 2024, that contamination has potentially reached <br /> the surface water flow regime within the Grassy Valley. CC&V concluded that the single <br /> sampling event was not statistically relevant to conclude that there is any contamination reaching <br /> surface water and may represent,at most,background concentrations of analytes. <br /> 12. The Division and CC&V held meetings throughout 2024 to discuss, among other <br /> matters, the ECOSA generally and the data collected from monitoring wells within the Grassy <br /> Valley area specifically. <br /> 13. In response to the Division's review of Grassy Valley monitoring reports CC&V <br /> has implemented measures designed to minimize migration of contaminated groundwater, <br /> 2 <br />