The New Mexico Supreme Court Holds that the Copper Mine Remediation Rule is Consistent with the Water Quality Act

Posted on September 24, 2018 by Thomas Hnasko

Since 2013, when the New Mexico Water Quality Control Commission (“WQCC”) enacted the most comprehensive Copper Mine remediation rule in the country, the Attorney General and various NGOs have continued to challenge the rule because it established, on an industry-wide basis instead of through a case-by-case determination, “foreseeable places of [groundwater] withdrawal” at mine sites that are protected from contamination under the New Mexico Water Quality Act.  Initially, the Court of Appeals rejected the Attorney General’s challenges in Gila Resource Information Project v. N.M. Water Quality Control Comm’n, 2015-NMCA-076, 355 P.3d 36, holding that the determination of a protectable “place of withdrawal” has always been and remains a matter committed to the Commission’s discretion.  The Supreme Court granted certiorari to consider the question, and has now reaffirmed the Court of Appeals’ decision, but did so focusing on language directly from the Water Quality Act itself, rather than relying on the Commission’s discretion.

In Gila Resources Information Project v. N.M. Water Quality Control Comm’n, 2018-NMSC-025, 417 P.3d 369, the Attorney General repeated the argument that the Copper Rule allegedly failed to protect foreseeable places of withdrawal at mine sites because it allowed the placement of monitoring wells – at which water quality standards would be measured – to be located outside of open pits, waste stockpiles, or other active mining units.  According to the Attorney General, this placement of monitoring wells necessarily ignored the existence of protectable groundwater within the confines of those wells.  As such, the Copper Rule violated the Water Quality Act’s proscription against issuing permits for any mining facility that contaminated groundwater at “foreseeable places of withdrawal.”

Not so, said the New Mexico Supreme Court.  If the Water Quality Act prohibited water contaminants in excess of applicable standards at the location of any “discharge,” the Court reasoned that petitioners may be correct.  However, the statute itself provides that groundwater quality “shall be measured” at “foreseeable places of withdrawal.”  The Court accepted respondent’s interpretation as the “most sensible reading” of this requirement, concluding that the “shall be measured” language implies that groundwater must actually be brought to the surface for analysis and measurement.  Of course, the normal method for bringing water to the surface is through samples collected from a monitoring well.  The Court found that the measurement of groundwater quality “at any place of withdrawal” means that the New Mexico Environment Department, when acting on a permit, must select specific locations for the placement of those monitoring wells.  According to the rule, those locations must be as close “as practicable” to the open pits, waste piles and active mine units.

Thus, based on the practical consideration that groundwater quality must be measured for compliance with standards at a monitoring well, the Court relied on statutory construction, rather than on the discretion afforded to the WQCC, to hold that the Copper Rule develops a sensible procedure to protect groundwater at foreseeable places of withdrawal.  In this regard, the Supreme Court’s decision departed from the Court of Appeals’ analysis and upheld a comprehensive copper mine remediation rule that will likely be followed by other copper-producing jurisdictions.