The Chino, Cobre and Tyrone mine facilities are open-pit and underground copper and iron mining, beneficiation, and processing facilities owned and operated by Freeport-McMoRan Corporation. Hazardous substances released from the mine facilities included sulfuric acid and metals/metalloids, including arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, selenium, and zinc.
The mine facilities are located in southwest New Mexico.
State of New Mexico
United States Fish and Wildlife Service
The New Mexico Office of Natural Resources Trustee (ONRT) completed a natural resource damage assessment for groundwater injury for the mine facilities. The ONRT and Freeport-McMoRan reached a $13,000,000 settlement for groundwater resource damages resulting from the release of hazardous substances from the mine facilities. The groundwater settlement was approved by the U.S. District Court in a February 11, 2011 consent decree. The settlement consisted of approximately $12,794,308 for the restoration of groundwater resources and $205,691 for the reimbursement of outstanding damage assessment costs. A description of groundwater restoration projects selected to offset resource injuries is provided in the Final Groundwater Restoration Plan for the Chino, Cobre, and Tyrone Mine Facilities.
The ONRT together with co-Trustee United States Fish and Wildlife Service (FWS) and Freeport-McMoRan reached a $5,500,000 settlement for injury to wildlife and wildlife habitat resources. The consent decree, approved by the U.S. District Court on February 21, 2012, included past costs of approximately $59,750 and the transfer of 715 acres of land to New Mexico State Parks’ City of Rocks Park. City of Rocks State Park is located north of Deming, N.M., and is representative of the high desert grassland habitat of the Chihuahuan desert. A description of wildlife restoration projects selected to offset resource injuries is provided in the Wildlife and Wildlife Habitat Restoration Plan and Environmental Assessment for the Chino, Cobre, and Tyrone Mine Facilities and the Addendum to the Wildlife and Wildlife Habitat Restoration Plan and Environmental Assessment for the Chino, Cobre and Tyrone Mine Facilities.
A description of groundwater and wildlife restoration projects selected to offset resource injuries is provided in the Final Groundwater Restoration Plan for the Chino, Cobre, and Tyrone Mine Facilities, the Wildlife and Wildlife Habitat Restoration Plan and Environmental Assessment for the Chino, Cobre, and Tyrone Mine Facilities and the Addendum to the Wildlife and Wildlife Habitat Restoration Plan and Environmental Assessment for the Chino, Cobre and Tyrone Mine Facilities. Completed and on-going restoration projects are listed below starting with the groundwater projects and followed by the wildlife projects.
Groundwater Restoration Projects
Bayard Wastewater Reuse
The Wastewater Reuse project consisted of building an addition onto the City of Bayard’s existing wastewater treatment plant to allow for the municipal reuse of treated water. The new addition has enabled groundwater conservation by using treated wastewater for irrigation. Targeted locations for the reuse water include the sport fields of Bayard Elementary School, Snell Middle School, and Cobre High School; the City’s Little League fields; and the City’s new cemetery. Other locations that could use treated water may be added in the future. The new addition to the waste water treatment plant includes a filter pump building, a large storage tank, associated piping and controls, and transmission lines to accommodate current flows from the wastewater treatment plant as well as increased flows in the future. Work at the treatment plant was completed in October 2015 and irrigation of the cemetery started in late 2017. The City has secured a consultant for the design of the necessary infrastructure for the school and little league fields.
Hurley Sewer Line Replacement
Many of Hurley’s older sewer main lines were constructed using clay material. Sections are degraded and have failed over time, causing backups into private residences and posing a threat to groundwater quality. Restoration activities included the replacement of one sewer section and the relining of five other failing, vitrified clay pipe sections. The restoration work was completed in 2014.
Santa Clara Gravity Sewer Improvements
Two main municipal sewer lines in the Village located along Cameron Creek were prone to stormwater damage and sewer flow constriction, which resulted in contamination of surface and groundwater resources. The project replaced, heavily fortified, and protected a section of sewer line that runs under Mill Street and crosses Cameron Creek. This sewer line and the Mill Street crossing were prone to breaks and failure during high run-off events at Cameron Creek. The Mill Street crossing, which used to be a dirt road with a basic culvert at Cameron Creek, was paved, concreted, and fortified so that both the road and the sewer line under it should remain intact for years to come. The project also replaced an existing sewer line that was constricted by tree roots located adjacent to Cameron Creek and provided for the purchase of a sewer line cleaning machine (rodder) for regular maintenance of all sewer lines. This restoration project was completed in 2014. Sixty-nine residences and one commercial entity benefitted from this project.
Santa Clara Wellhead Protection
Prior to ONRT funding, the wellheads for the two main water production wells near the Village were in poor condition and exposed to the elements. The concrete pad seals and foundation of both wellheads were cracked and corroded and had no enclosures over the wellheads resulting in an increased risk of groundwater contamination via runoff and infestation. The project consisted of demolition and replacement of the wellhead concrete pads and foundations, and construction of building enclosures. The restoration project was completed in 2013.
San Vicente Creek Mill
The San Vicente Creek Mill is the site of former milling and smelting operations for lead, silver, copper, and gold that operated from the 1880s to the 1940s. As a result of the milling and smelting operations, a tailings pile was left behind at the site with an approximate volume of 22,000 cubic yards. Water quality at the site was impacted by erosion of the tailings pile and the subsequent transport of heavy metals such as lead to surface water and groundwater. Restoration actions included excavation and consolidation of onsite and offsite tailings and contaminated soils (estimated at 24,500 cubic yards); transportation and proper disposal of tailings and contaminated soils; restoration of disturbed areas with replacement of excavated materials; and reseeding with an appropriate native or adaptive seed mixture. Restoration activities are complete and periodic inspections to mitigate any significant erosion issues were implemented through early 2016.
Silver City North/Blackhawk Sewer Line Extension
The project extended municipal sewer lines to a neighborhood in the northern portion of Silver City composed of 34 residences that used on-site wastewater septic systems. By connecting to the municipal sewer service, the project will eliminate the potential threat of groundwater contamination from those homes with faulty on-site septic systems. The project was completed in May 2015 and consisted in the trenching and installation of approximately 4,300 linear feet of 8-inch diameter PVC and ductile iron sewer pipes and associated manholes along 3 residential streets and 2 easement sections. As of February 2018, 32 residences have connected to the system.
Silver City Ridge Road East Sewer Line Extension
The project extended existing municipal sewer lines to a residential area south of Silver City and has provided connections to 141 residences that were using on-site wastewater septic systems. Approximately 21 additional residences still need connections. Connection to the municipal sewer system protects groundwater from contamination from faulty septic systems.
The project consists of two phases: the first phase was the extension of the main sewer collection lines and the second phase is the individual service connections to each dwelling and the proper abandonment of existing septic systems. Construction of the main sewer lines along six residential roads started in April 2017 and was completed by March 2018. Approximately 13,600 linear feet of sewer collection lines were installed during this effort. The second phase of the project was initiated in October 2017 and is on-going.
Wildlife and Wildlife Habitat Restoration Projects
Ancheta Springs Ranch Conservation Easement and Restoration
This project protects approximately 910 acres of valuable wildlife habitat on the Ancheta Springs Ranch in perpetuity by enabling the ranch owners to voluntarily put a conservation easement in place on the ranch. The ranch is located in the Mimbres River Watershed, about 21 miles east of Silver City. The conservation easement was implemented in 2014. Agreements between the Trustees, the landowners, and a restoration contractor were finalized in January 2018. Restoration actions started in mid-2018 and consisted of active stream restoration along portions of Ancheta Creek and other tributaries in the form of rock dams, low-stone structures, and native seeding. Field activities have been completed and a final report from the proponent is expected by the end of November 2019.
Burro Cienaga Side Channel, Floodplain, and Low Terrace Restoration
This project continued on-going restoration along a reach of the Burro Cienaga located on the Pitchfork Ranch. The ranch encompasses approximately 5,160 acres and is located about 23 miles south of Silver City. The objective of the restoration work is to stop erosive down-cutting of the stream channel and drainages, and thereby maintain the cienaga as a perennial wetland, which provides key habitat for birds and other wildlife. Trustee-funded restoration activities started in February, 2015 and were completed in September, 2017. The work mostly consisted of the installation of erosion control structures in two canyons and numerous side channels in the floodplain, and the creation of terraces and up-slopes along the sides of the cienaga.
Burro Cienega Watershed Restoration
This project restored riparian and wetland habitats throughout the Upper Burro Cienega Watershed with the repair of severe erosion damage to the Burro Cienega. It also reconstructed stock tanks and ponds for the benefit of migrating waterfowl and other wildlife. The restoration activities took place on privately-owned ranches and in the Gila National Forest, all areas located about 22 miles southwest of Silver City. Restoration activities started in late 2014 and were completed by August 2019.
City of Rocks State Park Wildlife Habitat Restoration
The City of Rocks State Park is located approximately 22 miles southeast of Silver City and encompasses approximately 2,935-acres, which includes 716-acres of land recently acquired from the settlement reached between the Trustees and Freeport-McMoRan in 2012. The project aims to enhance and restore existing water resources in the park to benefit wildlife and wildlife habitat. The proposed project includes restoration of the hydrology at Faywood Ciénega, habitat improvement at two stock tanks fed by springs, and erosion control measures at the main campground. A grant agreement to implement the project was finalized in March 2018 between the Trustees and NM State Parks. Restoration work started in early 2019 and is on-going.
Double E Ranch Habitat Protection and Improvement
The acquisition of the Double E Ranch protects and restores riparian habitat and maintains perennial flow along Bear Creek. Restoration actions focus on passive restoration, including allowing riparian vegetation to reestablish naturally, and may include changes to grazing management or construction of exclosure fences to limit grazing and off-road vehicle use in the riparian areas. The property, which consists of 5,900 acres of deeded land, was acquired by the New Mexico State Game Commission in 2014.
Gila River Farm Riparian Preserve
This project consisted of the construction of a shallow, seasonal wetland for wintering waterfowl and migratory birds along the Gila River. The wetland was constructed in the Gila River Farm, a tract of land within The Nature Conservancy’s Gila Riparian Preserve, which is located approximately 23 miles northwest of Silver City. The Preserve covers an area of 1,300 acres and spans 5 miles of the 14-mile long Cliff-Gila Valley. The project involved the creation of a 3-acre shallow seasonal wetland adjacent to an already existing 6-acre wetland. Field activities started in early 2019 and are anticipated to be completed by October 2019.
Headwaters Burro Ciénega Watershed Restoration
The headwaters of the Burro Ciénega are located in Gila National Forest and on private lands approximately 23 miles southwest of Silver City. The Burro Ciénega watershed is comprised of approximately 109,257 acres of land owned by the Gila National Forest, New Mexico State Land Office, Bureau of Land Management, and private individuals. Ranchers in this area have grouped together to form the Upper Burro Ciénega Watershed Association, which works to restore and enhance habitat conditions and overall watershed health. This area is relatively unique in that a portion of the drainage is perennial (fed by local springs) and it sits within an otherwise dry Chihuahuan desert landscape. The perennial portion of the drainage is known as Burro Ciénega, and is home to fish, birds, and other wildlife. Indeed, ciénegas are one of the rarest habitat types in the semiarid southwest and provide important functions to migratory bird species. The work proposed under this project includes planting riparian shrub and tree buffers on suitable streambanks in the headwater portion of the ciénega and identifying, locating, and treating undesirable non-native State listed noxious plant species. Restoration activities within the Gila National Forest started in early 2018. The project is expected to continue through 2021.
Mimbres River Wildlife and Habitat Restoration
This project is a collaboration of several public and private landowners working together to restore riparian and wetland habitats throughout the Mimbres River watershed. The sites are located about 17 miles east and northeast of Silver City along the Mimbres River. Restoration activities started during the first half of 2015. Two types of projects were completed by September 2017: riparian restoration and stock pond restoration. Riparian restoration actions includeed removing invasive plant species, and stabilizing and restoring eroding riverbanks. The stock pond restoration project transformed a large old stock pond that did not hold water into a surface water wetland pond. This project was completed in 2017.
Prevost Ranch Conservation Easement
The Prevost Ranch is a 2,760-acres working ranch located approximately 22 miles south-southwest of Silver City. The property is located within the Burro Mountains and consists of approximately 299 acres of riparian habitat, one acre of freshwater ponds, and a mix of upland habitat including Chihuahuan desert grassland and montane shrub habitat, all areas of important wildlife habitat. The landowners had expressed a desire to permanently protect the entire property from subdivision and ranchette development through a conservation easement. This project provided the financial support needed to purchase the easement and cover the associated transactional and stewardship costs. The New Mexico Land Conservancy performed the necessary due diligence activities and closed on the easement acquisition in December 2017.
River Ranch Habitat Protection and Improvement
This project provides protection and restoration of native riparian habitat along the Mimbres River through the purchase and conservation of the River Ranch property (1,010 acres of deeded land). This is the lowest reach of the river that still flows perennially. Restoration activities focus on passive restoration including fencing the riparian corridor to prevent stream bank erosion from grazing cattle which improves hydrologic function and stimulates natural regeneration of riparian plants. The property was acquired by the New Mexico State Game Commission in 2014.
Southwest Sufi-Bear Creek Conservation Easement and Habitat Improvement
This project involves protecting approximately 1,453 acres of the Southwest Sufi-Bear Creek property under a conservation easement. The property is located approximately 14 miles northwest of Silver City. The Southwest Sufi-Bear Creek property includes 2.6 miles of Bear Creek, which bisects the property, and abuts the Gila National Forest. Bear Creek ultimately joins the Gila River, which is one of the few major river systems of the southwest and supports one of the highest levels of aquatic and riparian biodiversity in the Lower Colorado River Basin. The landowners were interested in permanently protecting the property, which would prevent further fragmentation of the critical riparian habitat in this area. Additional work to repair fencing on the property will help protect valuable wildlife habitat from trespassing cattle. The New Mexico Land Conservancy performed the necessary due diligence activities and closed on the easement acquisition in January 2018.
Upper Whiskey Creek Restoration
The Upper Whiskey Creek property is privately owned and is located approximately 6 miles northeast of Silver City. The project area is approximately 42 acres with 0.82 acres of ponds and dirt tanks. The property is within the 2,000-acre Whiskey Creek watershed. This project would create wetland ponds, clean out and excavate dirt tanks, remove invasive vegetation and plant native riparian/wetland vegetation, perform earthwork to prevent erosion, and restore surface water hydrology to benefit wildlife and wildlife habitat. Field activities started in the spring of 2019 and are expected to be completed by the summer of 2020.