Pima County files their comments on ADEQ’s draft Copper World Aquifer Protection Permit
Below are some key points from Pima County’s comprehensive comments on the draft Copper World application permit, filed by Pima County with ADEQ on March 11, 2024.
Also, SSSR's own comments will be released to our members by approximately March 27. This will be plenty of time for you to read through our comments in time for the ADEQ comment deadline on March 10, the deadline for you to submit your own comments.
Read Pima County's comments here.
Submit your own comments to ADEQ here.
View ADEQ’s draft APP and executive summary here.
NOTE: Below we have excerpted some of the 56 points in Pima County's comments that we thought might be most helpful to you. Use the link above to refer to Pima County's complete comments for more details.
#19. Request complete survey of shafts, adits, and other voids that could affect transport of pollutants to the aquifer.
#21-24. Request a comprehensive storm management plan and that methods be required to route stormwater around heap leach facilities rather than relying exclusively on underground pipe drains that could be inadequate or fail.
#28. Require that TSFs (tailings storage facilities) have lines to minimize seepage into the aquifer. Linings are not now prescribed in the APP. Pima County’s comments note in #28 that “The Tailings Storage Facilities have among the largest potential for aquifer pollution, and yet are prescribed among the least amount of protection” (p. 11).” Page 12 of Pima County’s comments states that, “It is not acceptable that the excess water from the TSF be allowed to seep into the ground as a compromise in practicality. If the design of an unlined TSF is not environmentally protective, then it should not be approved. If the design of a lined TSF to receive a 30% water content slurry is not practical or safe due to stability, then it should not be approved. A reasonable solution is to line the TSF and to stack dry tailings, which clearly accomplish the goals of environmental protection.”
#30-31. Any east-side discharge of water from the East Pit and Broadtop dewatering wells be subject to state water quality standards.
#34. “Pima County requests that the monitoring frequency be adjusted in Table 20 from biennial (once every two years) to semi-annually (twice per year).”
#36. “Pima County requests additional west-side POC wells located farther downgradient from the outermost discharging facilities. There are dozens of domestic water wells downstream and less than five miles of discharging facilities, and with the Tucson Basin being a sole source aquifer, these drinking water resources must be protected.”
#40. “Pima County requests two additional point of compliance wells be established to ensure that the east-side aquifer is not impaired by operations at the East Pit.“
#47. “[T]here must be POC wells established that are hydrologically downgradient of the Rosemont Pit and along the Backbone fault to verify the assumptions presented in the application by Hudbay. Monitoring must occur at these POC wells as required at all other POC wells. Additionally, these new POCs should be monitored even after the point at which the Rosemont Pit becomes a hydraulic sink and continually until the end of the post-closure period.”
#48. “Pima County requests that a minimum frequency of waste rock acid content analysis be defined for continued operations following the first year… Pima County recommends that a minimum frequency be required for analysis of waste rock even after the first year of operation.
#49. “In the event of dry-weather ponding or seepage being observed in washes on the perimeter of tailing storage facilities, efforts to monitor the discharge and correct drainage must be undertaken.”
#52. “Pima County requests that the soil cover be at least 1 meter on the TSF and the HLF, as this is the minimum thickness tested (tests were between 1-2 meters) in the 2017 Global Cover System Design Technical Guidance Document writen by the International Network for Acid Prevention… Hudbay says the tops will receive an 18-inch soil cover, and the embankments will receive a 24-inch cover. Pima County questions the sources that determined that this is an appropriate amount of material to support growth of vegetation… If the thickness of the soil covering is too thin, then not only will the media not support vegetation establishment, but it will fail in its roles of contaminant migration and erosion control.”
#53-54. Hudbay says in Section 10.3.1.7 that “The waste rock [facility] will be revegetated directly without the placement of a soil cover.” Pima county requests clarification and explanation as to how Hudbay plans to revegetate a pile of waste rock without any further soil amendments. With no soil, Hudbay will not achieve its ranching and wildlife habitat objectives for mine land reclamation.
Pima County requests that ADEQ require the applicant demonstrate that adequate soil cover can be derived from on-site locations to achieve waste rock reclamation. If on-site soil cover is inadequate, closure costs should include offsite purchase and transfer costs for covering and closing the APP facilities.