Colorado Mining Plan Adjusts Discharge Policies for Lake Christina and Milton Reservoir

In a recent meeting held on July 16, 2025, the Colorado Mining Land Reclamation Board (MLRB) discussed critical findings from environmental sampling related to dredging operations at Lake Christina and the Northern Settling Basin. The meeting, conducted via Zoom, highlighted the results of water quality and sediment analyses, which are essential for ensuring compliance with state regulations and protecting local ecosystems.

The sampling conducted at various locations revealed that metals such as arsenic, barium, chromium, and lead were detected at levels below regulatory standards. However, two volatile organic compounds (VOCs), dimethyl phthalate and vinyl acetate, were identified without established regulatory benchmarks for comparison. Notably, methylene chloride was found in sediment samples at concentrations exceeding groundwater standards, raising concerns about potential contamination sources. Despite this, officials clarified that methylene chloride is not used in the dredging process, suggesting that the elevated levels are not attributable to the current operations.

The board emphasized the importance of ongoing monitoring, with the applicant committing to a monthly sampling plan that includes testing for metals and VOCs. Results will be reported quarterly to the Division of Reclamation, Mining, and Safety (DRMS), ensuring transparency and accountability in environmental management.

Another significant topic of discussion was the historical discharge of sediment into Lake Christina via the Evans Number 2 Ditch. The applicant previously discharged excess materials into this ditch, which flows into the lake. However, the mining plan has since been revised to prevent any further discharge into the ditch, directing all water back into the Milton Reservoir instead.

The meeting underscored the MLRB's commitment to environmental stewardship and regulatory compliance as the dredging operations continue. The board's proactive approach aims to mitigate potential impacts on local water quality and ensure that the dredging activities align with Colorado's environmental standards. As the applicant moves forward with its operations, the ongoing monitoring and reporting will be crucial in addressing community concerns and safeguarding the region's natural resources.