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RPA Overview

The Reclamation Plan Amendment (RPA) area covers 921 acres of the Permanente Quarry site. The plan calls for the site to be reclaimed in multiple phases focused on six areas:

The Quarry Pit

The quarry pit is a 198-acre area on the hillside where mineral extraction has historically occurred. Its elevations range from approximately 550 feet above mean sea level (amsl) to 1,750 amsl, while the surrounding topography ranges from 1,000 ft amsl to 1,750 ft amsl

To reclaim the pit and stabilize the new surface, reclamation of the quarry pit will require backfilling the pit to an elevation of approximately 990 ft amsl and then placing a buttress to stabilize the remaining high walls of the pit, leaving a final slope towards the southeast. Vegetation will be planted to further stabilize the surface.

The pit will be filled with approximately 42 million cubic yards of onsite overburden material, concrete and suitable imported soil.

  • Illustration of current pit dimensions including, lower elevations, upper elevations, north highwall, and existing ridge along the north Quarry highwall.
  • Illustration of the fill at lower elevations and stabilized bench configuration for highwalls.
  • Illustration of the updated buttress area below the crest of the north highwall.
  • Illustration of generation of on-site backfill materials via the greenstone of the west wall of the Quarry pit, the upper Quarry slope stabilization, the grading at the shop and office area, and excavation of lower WMSA.
  •  Illustration of fill level after soil has been imported

    West Materials Storage Area

    The West Materials Storage Area (WMSA) is a 210-acre area where 48 million tons of low-grade limestone and greenstone were previously placed. 

    The reclamation plan calls for using some of these materials to fill the quarry pit while leaving others in place.

    Leaving some materials in place will reduce near- and long-term surface and groundwater quality impacts by avoiding the re-disturbance of previously placed materials.

    The WMSA area will be re-graded for stability and capped with cover material and soil for revegetation.

    •  Illustration of current WMSA with dimensions and current gradation,
    • Illustration of updated 2.25:1 WMSA gradation with cover material and soil

      East Materials Storage Area

      The East Materials Storage Area (EMSA) is a 65-acre area encompassing 6.5 million tons of low-grade limestone and greenstone overburden material.

      The EMSA will be re-graded for stability and capped with cover material and soil for revegetation.

      • Illustration of current EMSA with gradation
      • Illustration of updated 2.25:1 EMSA gradation with cover material and soil

        The Shop and Office Area

        The Shop and Office, encompassing 64 acres, currently contains crushing stations, offices and maintenance areas. This area will continue to support aggregate operations at the rock plant, and ultimately limited grading is required for geotechnical stability.

        • Illustration of current shop and office area (with general building dimensions)
        • Illustration of area with limited grading for slopes between 2:1 and 3:1. Illustration of area with limited grading for slopes between 2:1 and 3:1

          Rock Plant Area

          The Rock Plant, located on the south side of Permanente Creek, covers 19 acres on gentle slopes.

          The Rock Plant is an active processing facility for construction aggregates and will continue operations into the foreseeable future.

          Eventually, the equipment and excess materials will be removed, and the area will be re-graded and covered with non-limestone materials. 

          • Illustration of location of rock area within RPA site
          • Illustration of area with equipment removed and 3:1 gradation

            Permanente Creek Reclamation Area

            The Permanente Creek Restoration Area is a 49-acre area located along Permanente Creek.

            The slopes along Permanente Creek will be reclaimed. Flattening the slopes will enhance the lower WMSA surfaces, provide improved cover options and long-term stormwater management, and enhance the success of the Permanente Creek Restoration Project.

            • Illustration of the current state of the creek area,

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