WAT-2005-02 Natural Acid Rock Drainage in Colorado: Overview and Recent Investigations Download Publication Details A presentation and review of recent investigations on the issue of natural acid rock drainage (NARD) and surface water quality in Colorado. 47 pages. Digital PDF download. WAT-2005-02D Citations Sares, Matthew A. “WAT-2005-02 Natural Acid Rock Drainage in Colorado: Overview and Recent Investigations.” Water Resources presented at the Colorado Geological Survey, Denver, CO, July 22, 2005. https://coloradogeologicalsurvey.org/publications/natural-acid-rock-drainage-colorado.