Routine groundwater monitoring of a well at the Washington National Primate Research
Centers (WaNPRC) located on the Salt River Pima-Maricopa Indian Community (SRPMIC)
land recently identified perchlorate levels that reached the designated threshold for
activating the facility’s contingency plan. Perchlorate is a chemical compound that can be
both manufactured and naturally occurring.
The perchlorate levels were detected by the sampling vendor hired by the company
contracted to Nammo Defense Systems (NDS). Nammo is taking the lead to facilitate
environmental cleanup of the site. As part of the remediation responsibilities, regular
groundwater testing results are provided to the WaNPRC and all relevant regulatory
partners. Although no statewide regulatory limit for perchlorate in groundwater exists in
Arizona, the Arizona Department of Health Services has developed a drinking water
health-based guidance level of 11 micrograms per liter (μg/L) for the compound. This
concentration was developed to protect the most sensitive population, children. The most
recent detected levels of 6.6 micrograms per liter (μg/L) does not exceed this level but it
does exceed the action threshold established in coordination with University of
Washington, WaNPRC, and NDS, and this prompted immediate protective measures.
NDS activated the contingency plan to safeguard the health and safety of the research
animals at WaNPRC and began delivering potable water to the facility to minimize
operational impacts while strategic consideration for a long-term water filtration solution
is developed.
NDS also notified and is actively coordinating with regulatory and community partners,
including the Salt River Pima-Maricopa Indian Community (SRPMIC), the US
Environmental Protection Agency (EPA), and the Arizona Department of Environmental
Quality (ADEQ). WaNPRC is also actively collaborating with these agencies as it follows its
response strategy.
For questions or concerns, please contact: uwnews@uw.edu.
June 18, 2025