Permanente Reclamation

The topography of the Permanente property is generally steep. Under the proposed RPA, the Quarry highwalls will be covered by fill at lower elevations and reclaimed in a stabilized benched configuration at upper elevations. Additionally, the upper bench will meet current seismic standards, and the buttress area below the crest of the north highwall will remediate unstable conditions of the upper Quarry walls. The buttress design will maintain the height of the existing ridge crest along the north Quarry highwall. A portion of the on-site suitable backfill materials will be generated via regrading the greenstone slide of the west wall of the Quarry, upper Quarry slope stabilization, grading at the shop and office area, and excavation of the lower WMSA. The remaining soil will be imported clean fill from, e.g., regional infrastructure and construction projects, and other sources. Vehicle and truck traffic required to accomplish fill import will be similar to historic baseline levels at the facility.

The WMSA is an approximately 173-acre area with about 48 million tons of low-grade limestone and greenstone. Under the proposed RPA, most of the WMSA will remain in place to ensure long-term surface and groundwater quality. Importantly, the reduction of WMSA materials used as Quarry backfill will also serve to reduce risks to water quality. The WMSA will be graded to 2.25:1 or flatter, and capped with cover material and soil for revegetation.

The EMSA is an approximately 75-acre area with a design capacity of 6.5 million tons of waste rock. The EMSA will be graded to 2.25:1 or flatter and capped with cover material and soil for revegetation. Closure of the EMSA pursuant to the proposed 2023 RPA and the sites’ WDRs will ensure that the materials are adequately protected and isolated.

The Shop and Office, consisting of primary and secondary crushing stations, offices, and maintenance areas, will continue to support aggregate processing operations and equipment for the proposed reclamation and closure process. Limited grading is scheduled for this area with final slopes between 2:1 and 3:1. Ultimately, buildings and equipment will be removed.

The approximately 19-acre Rock Plant will remain an active rock processing facility for construction aggregates, consisting of crushing, conveying, screening, and processing facilities that produce various types of aggregate products, which will be stored in stockpiles until transported to customers. Ultimately, equipment will be removed and the area graded at 3:1 slopes.

The main haul road adjacent to the Cement Plant provides access for all vehicles and equipment from the site entrance to the reclamation areas, and will remain following reclamation for site access.

The Permanente Creek Reclamation Area is an approximately 49-acre historic mining location adjacent to the WMSA, which does not require reclamation under SMARA because the disturbance pre-dated SMARA’s effective date. Despite this, Lehigh has voluntarily agreed to reclaim that area.