Using Spreadsheets to Evaluate the Effects of Mine Water Disposal on Surface and Ground Water

摘要

Spreadsheets can accurately model effects on water quality resulting from the disposal of treated and untreated mine waters by percolation or land application disposal. User-friendly spreadsheets are a valuable tool to evaluate potential effects of a new mine, proposed revisions to an operating permit, disposal of adit water, and water disposal options when closing tailings impoundments. The spreadsheet models use basic data (hydrogeologic, wastewater quality and quantity, treatment, storage, and disposal system capacities), Darcy's equation, standard mixing zone calculations, and weighted-average equations in calculations that are consistent with NPDES permitting calculations. Formulas and input values may be adjusted to reflect life-of-mine changes in water quality/quantity, hydrogeologic data, water treatment efficiency, disposal method, volume, etc. The use of spreadsheets is an innovative approach to identify water disposal requirements and the more critical elements of a water management system so that the most effective capital investment can be made during operations and to identify operational mitigations that should be implemented to avoid costly issues during closure.