|
April 1, 2024
<br /> Page 2
<br /> Water Quality
<br /> The District's Colorado Discharge Permit System permit from the Colorado Department
<br /> of Public Health and Environment("CDPHE")requires the District to sample and analyze effluent
<br /> for the following pollutants: arsenic, cadmium, chromium, copper, lead, mercury, molybdenum,
<br /> nickel, selenium, silver, zinc, cyanide, and phenols. The District spends significant time and
<br /> money on its efforts to comply with its discharge permit and cannot afford to have its operations
<br /> jeopardized by nearby activities that might impact its ability to meet CDPHE's strict permit limits.
<br /> The District's permit limit for total mercury is 0.077 µg/L. Low level mercury is present
<br /> throughout Leadville in the soil, water, and air due to historic mining operations. The District is
<br /> subject to similarly strict permit limits for cadmium and zinc. Even extremely small additional
<br /> quantities of mercury, cadmium, or zinc—such as in wastewater resulting from worker
<br /> handwashing at the Mill—could, upon transfer to the District's facility, cause the wastewater in
<br /> the District's polishing pond and discharge to exceed the permit limits. The District is concerned
<br /> that the Applicant's proposed increased operations will make it difficult to continue meeting its
<br /> discharge permit limits, particularly given the elevated concentrations of mercury and cadmium
<br /> reported for the mill tailings, and the Applicant's proposed use of zinc dust in the Mill operations.
<br /> See JVA Memo. Moreover, when the District's permit is renewed, CDPHE could impose
<br /> additional limits for other consituents if they are detected in effluent at levels that present a concern
<br /> for human health or the environment.
<br /> The Application also acknowledges that the District's facilities could be affected by an
<br /> extraordinary storm event. Application,Exhibit S,Appendix 19-6. The Applicant states that under
<br /> the Stormwater Management Plan, flows would be diverted to "Outfall No. 2,"thereby reducing
<br /> the risk of damage to the sanitation facilities. It is unclear how that diversion would protect the
<br /> sanitation facilities, given that the outfall is located upgradient from the District's facilities.
<br /> Cyanide
<br /> Although processing gold ore with cyanide may be standard in the industry,it is not without
<br /> risk. The Material Safety Data Sheet("MSDS") for sodium cyanide shows it to be identified with
<br /> the following hazards: corrosive to metals, acute oral toxicity, acute dermal toxicity, acute
<br /> inhalation toxicity, and specific target organ toxicity(repeated exposure). It is fatal if swallowed,
<br /> in contact with skin, or inhaled. It is also "[v]ery toxic to aquatic life with long lasting effects."
<br /> Application, Exhibit U, Appendix 21-2.1 There have been a number of serious incidents around
<br /> the world involving cyanide spills and leaks. The amount of sodium cyanide the Applicant
<br /> proposes to use, 1,600 pounds per day, is substantial. Application, Exhibit D, Table 4-11. The
<br /> mere fact of the next-door neighbor using so much cyanide gives the District concern for the safety
<br /> of its employees, the community, and downstream aquatic life.
<br /> See also MSDS for sodium cyanide,Cat.No. S284I-100,S2841-500,available at www.fishersci.com(revised Dec.
<br /> 24,2021).
<br />
|