A Preliminary Evaluation of the Potential for Surface Water Quality Impacts from Fly Ash Disposal at the Navajo Mine, New Mexico

The analysis of monitoring data at the Navajo Mine contradicts BHP Billiton's claims of negligible environmental impact, finding elevated ash-constituent parameters in groundwater and significantly higher concentrations of TDS, SO4, pH, selenium, and boron downstream in the Chaco River basin compared to upstream.

• Analysis of the Bitsui Wash monitoring network showed increasing trends and elevated levels of ash-constituent parameters in the down gradient groundwater flow direction, suggesting that diffusion of ash constituents is occurring in wells near the ash well.
• The monitoring network used by BHP Billiton contains serious deficiencies, most notably a background well positioned to intercept water that has already passed through the mine for 30 years, which undermines its ability to detect offsite migration of ash constituents.
• A large-scale evaluation of the Chaco River and its tributaries found that downstream concentrations of selenium, pH, SO4, and TDS were more than three times higher than upstream concentrations, while boron concentrations were nearly 12 times higher downstream.

APA

Clean Air Task Force (2005). A Preliminary Evaluation of the Potential for Surface Water Quality Impacts from Fly Ash Disposal at the Navajo Mine, New Mexico. https://www.catf.us/resource/a-preliminary-evaluation-of-the-potential-for-surface-water-quality/

Chicago

Clean Air Task Force. A Preliminary Evaluation of the Potential for Surface Water Quality Impacts from Fly Ash Disposal at the Navajo Mine, New Mexico. 2005. https://www.catf.us/resource/a-preliminary-evaluation-of-the-potential-for-surface-water-quality/.

Wikipedia

{{cite report |author=Clean Air Task Force |title=A Preliminary Evaluation of the Potential for Surface Water Quality Impacts from Fly Ash Disposal at the Navajo Mine, New Mexico |date=1 May 2005 |url=https://www.catf.us/resource/a-preliminary-evaluation-of-the-potential-for-surface-water-quality/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{cleanairtaskforce2005preliminary, author = {{Clean Air Task Force}}, title = {{A Preliminary Evaluation of the Potential for Surface Water Quality Impacts from Fly Ash Disposal at the Navajo Mine, New Mexico}}, institution = {Clean Air Task Force}, year = {2005}, month = may, url = {https://www.catf.us/resource/a-preliminary-evaluation-of-the-potential-for-surface-water-quality/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }