Rosemont Copper Project Draft Reclamation Plan for the Utility Corridor
DRAFT – September 2013
DRAFT – September 30 2013
Reclamation Plan
Table of Contents 1
INTRODUCTION ............................................................................................................... 2 1.1. RECLAMATION PLAN METHODS ..................................................................................................... 2 2. PROJECT COMPONENTS ................................................................................................ 3 2.1. PROJECT FACILITIES ......................................................................................................................... 3 3. OVERVIEW OF EXISTING ENVIRONMENTS ............................................................. 5 3.1. VEGETATION ...................................................................................................................................... 6 3.2. VEGETATION COMMUNITIES ............................................................................................................ 6 3.3. SOILS ................................................................................................................................................... 8 3.4. DESCRIPTION OF SLOPE ................................................................................................................ 10 3.5. PRECIPITATION ............................................................................................................................... 10 4. RECLAMATION PLAN .................................................................................................. 10 4.1. RECLAMATION PROCESS ............................................................................................................... 11 4.2. RECLAMATION TREATMENTS DEFINITIONS ............................................................................... 13
Figures Figure 1.
Typical Utility Corridor Right‐of‐Way ................................................................. 4
Tables Table 1. Table 2. Table 3.
Typical Design Characteristics of the Utility Corridor (138kV Transmission Line and Water Pipeline) ............................................................. 4 Soils ..................................................................................................................................... 8 Disturbance Types Associated with the Utility Corridor .......................... 13
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Reclamation Plan
INTRODUCTION
This draft reclamation plan has been developed for the utility corridor associated with the Rosemont Copper Project. The utility corridor consists of a water pipeline (including booster pump stations), a permanent access road, and a 138kV transmission line. Requirements to reclaim the transmission line portion of the corridor are described in Condition 12 of the Certificate of Environmental Compatibility (CEC). In addition, the administrative final environmental impact statement (AFEIS) for the Rosemont Project contains language that requires the reclamation of lands which will be temporary disturbed during construction activities. Lands within the utility corridor that would be temporary disturbed and require reclamation treatments include transmission line structure work areas (around each tower), temporary access roads (spur), staging areas, pulling and tensioning sites, topsoil storage areas, booster pump construction areas, and other extra work space associated with the Project on lands managed by federal and cooperating agencies (e.g., State of Arizona, Pima County, USFS). Though this draft reclamation plan is standalone at this time, the intent is that it will be included within the reclamation plan for entire project as well as the Compliance and Mitigation Plan for the utility corridor. Components of the plan related to only the transmission line portion of the utility corridor will be included in the Construction, Mitigation, and Restoration and Plan (CMRP) required per Condition 12 of the CEC and by the Arizona Corporation Commission (ACC).
1.1. Reclamation Plan Methods The purpose of this plan is to describe and recommend reclamation treatments that will meet agency management and Rosemont Copper Project planning and operations reclamation and closure goals and objectives. The AFEIS contains an evaluation of environmental resources in relation to relevant management goals and objectives under the appropriate guidelines, and identified impacts associated with each resource potentially affected by the construction, operation, and/or maintenance of the Project. This plan identifies reclamation treatments, which are based on: (1) vegetation communities temporarily disturbed by the construction and operation of the utility corridor; (2) natural, unassisted recovery potential of each biotic community affected by the Project; and (3) susceptibility of disturbed soils to compaction and erosion. In general, the reclamation treatments described herein could be implemented during site preparation (i.e., grubbing operations), ROW construction, ROW reclamation, and closure reclamation activities (see Section 4.1). Typically, for locations where higher impacts to visual, biological, and land use resources have been identified, greater consideration for concentrated reclamation treatments may be appropriate. However, equally important is consideration of the vegetation community’s potential to rehabilitate itself naturally and with minimal reclamation treatments applied. For example, the semidesert grassland community will typically Page 2
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recover at a proportionately higher rate due to factors such as rapid growth of grasses, relatively homogenous vegetation diversity, and seed in the topsoil. Conversely, encinal oak communities typically have a lower natural recovery potential due to factors such as slow growth rates of key indicator plants, higher plant diversity, and shallow, rocky topsoil. While site‐specific conditions are a key factor in the application of reclamation treatments, these rehabilitation considerations will assist Rosemont Copper in appropriately allocating resources and efforts to rehabilitate Project disturbances. Following is a description of each disturbance type applicable to the utility corridor as it relates to the construction component.
2. PROJECT COMPONENTS This section introduces the components associated with the construction of the Project, and contains a brief description of the facility design, including the overhead transmission lines, tower and pole structures, foundations, water pipeline, pipeline pump stations, and access roads (see Table 1).
2.1. Project Facilities The water pipeline and transmission line would be constructed within the same 100’ utility corridor to the greatest extent practical. In areas where the two utilities diverge, access between the two corridors is to be kept to a minimum or to be overland drive and crush when possible. Figure 1 below is a general representation of a typical right‐of‐way in which the pipeline and transmission line are parallel.
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Figure 1. Typical Utility Corridor Right‐of‐Way 2.1.1.
Utility Corridor Features
Table 1 provides design characteristics typical of the utility corridor. Table 1.
Typical Design Characteristics of the Utility Corridor (138kV Transmission Line and Water Pipeline) Feature
Description Transmission Line – Approximately 13 miles 14 miles Water Pipeline – Approximately 14 miles Self‐supporting tubular 90 to 135 feet; range of height varies with span and terrain 600 to 800 feet (7 to 10 structures per mile) 100 feet Utility Corridor
Line length
Structure type Structure height Span length ROW width (typical)
LAND PERMANENTLY REQUIRED
To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers
Self‐supporting tubular Dead‐end tubular
LAND TEMPORARILY DISTURBED
Structure work area Wire pulling/tensioning sites Pipeline extra work space Booster station work areas
To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers ACCESS ROADS
Existing paved roads Existing dirt roads (no improvements) Existing dirt roads (with improvements) New overland access (drive and crush or clear and cut) New access road (bladed)
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To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers To be Provided by Pipeline and T‐Line Engineers
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2.1.2. 2.1.2.1.
Reclamation Plan
Transmission Line Self‐Supporting Tubular
The single‐pole tubular steel structure will be made of self‐weathering or galvanized steel. Typical structure height ranges between 90 and 135 feet, with an average structure span of approximately 600 to 800 feet. The SST has a small footprint and typically are used in areas of narrow or constrained right‐of‐way. 2.1.2.2.
Dead‐End Tubular
A single‐circuit, self‐supporting, DET structure made of self‐weathering or galvanized and structure height typically range between 90 and 135 feet. 2.1.2.3.
Structure Foundations
Self‐Supporting Tubular structures will be installed on a cast‐in‐place‐drilled pier foundation, typically 6 feet in diameter, but may range from 4 to 8 feet in diameter based on soil conditions. The drilled pier foundations will be 20 to 50 feet deep. 2.1.3.
Water Pipeline
The 20‐inch water pipeline will be constructed of iron and will be lowered into a trench – typically 4 feet in width. The trenching sequence consists of 1) scraping topsoil/seedbank, digging for pipeline trench with trench spoils stored on the edge of the ROW, lowering pipe into trench, backfilling with trench spoils, and spreading the topsoil/seedbank onto the disturbed area. 2.1.4.
Access Roads
Five types of access will be used for the utility corridor construction: existing paved roads, existing dirt roads that will not require improvements, existing dirt roads that may require improvements, new bladed access roads, and overland access. Access to the right‐of‐way will be via existing roads to the greatest extent practical. Final locations of new access roads created or existing roads with improvements for temporary or permanent access are to be determined after final engineering or – in the case of overland access – determined prior to construction. 2.1.5.
Booster Stations
To be provided.
3. OVERVIEW OF EXISTING ENVIRONMENTS Reclamation treatments will be specific to the setting of the Project and vegetation communities disturbed during activities associated with site preparation, ROW construction, ROW reclamation, and closure reclamation. In particular, seeding Page 5
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treatments require information to develop appropriate seed mixes that will incorporate the dominant plant species of the existing vegetation communities. In addition, vegetation clearing practices may vary based on dominant plant communities (e.g., cacti, agave, etc.).
3.1. Vegetation Vegetation data for the Project area were obtained from the Arizona Land Resource Information System, Pima County, and the Coronado National Forest (ALRIS 2010; Pima County 2005; USFS 2008, 2012). The vegetation‐based biome descriptions for the study corridor given below are primarily from Brown (1982a). The Brown, Lowe, and Pase system, developed for the Southwest, is the baseline used to identify and describe plant communities in the Project area. The hierarchical system includes various levels of detail and is intended to facilitate habitat delineation, biotic inventory and assessment, resource planning, and other biological activities (Brown et al. 1998). Based on field reconnaissance, these delineations revealed differences and are incorporated into the description below. The utility corridor for the Project is primarily located in the southern part of the Basin and Range Province and consists of two biomes—the Sonoran desertscrub/semidesert grassland transitional biome and the encinal oak biome. Biomes are major vegetation formations, such as desertscrub or woodland vegetation, centered in a geographic area, such as the Sonoran Desert. Within these two biomes are riparian plant communities that are periodically, seasonally, or continually submerged and are composed of emergent plants and life forms different from the immediately adjacent (upland) vegetation (Brown et al. 1998). Riparian areas are delineated, based on Pima County Regional Flood Control District data.
3.2. Vegetation Communities The four distinct vegetation communities associated with the Project include the (1) transitional zone between Arizona upland subdivision of Sonoran desertscrub and the semidesert grassland transitional community, (2) lower encinal oak subdivision of Madrean Evergreen Woodland, (3) xeroriparian vegetation communities, and (4) mesoriparian vegetation communities. However, approximately three‐quarters of the Project study area is located within the Sonoran desertscrub/semidesert grassland transitional community and xeroriparian vegetation communities, and the remainder of the Project is within encinal oak and mesoriparian vegetation communities. 3.2.1.
Sonoran Desertscrub/Semidesert Grassland
The majority of the Project study area west of the Santa Rita Mountains has been grazed by livestock for many years. Existing vegetation over most of the area tends to be sparse, with species of cholla (Cylindropuntia spp.), prickly pear (Opuntia spp.), Page 6
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and other cacti being common at lower elevations. Saguaro (Carnegiea gigantea) are present on the western side of the Project, but not common. Invasive (introduced or non‐native) plants associated with livestock grazing that occur in varying density include Lehmann lovegrass (Eragrostis lehmanniana), which is locally common, and snakeweed (Gutierrezia spp.). Tree species are mostly limited to littleleaf paloverde (Cercidium microphyllum) and low‐stature velvet mesquite (Prosopis velutina), both of which are more abundant along the xeric desert washes. The mesquite trees do not get very large because they are only supported by occasional rainfall. Farther to the east along Santa Rita Road, with an increase in elevation, vegetation density increases and transitions into semidesert grassland that supports abundant catclaw (Acacia greggii and Mimosa aculeaticarpa), ocotillo (Fouquieria spendens), yucca (Yucca spp.). This community is where the sensitive Pima pineapple cactus has been identified. Also, a limited amount of saguaro cacti occurs towards where the utility corridor starts to parallel Santa Rita Road. 3.2.2.
Encinal Oak Subdivision of Madrean Evergreen Woodland
At higher elevations along the western flank of the Santa Rita Mountains, grassland communitiesare supported, yet these areas are still dominated by trees and succulents. This scrubland/grassland gradually transitions into the encinal oak community as the utility corridor crests over the Santa Rita Mountains at Lopez Pass. Palmer’s agave (Agave palmeri), a variety of desert shrubs (Celtis pallida, Rhus trilobata), and clumps of beargrass (Nolina microcarpa) are commonly found. Along each side of the ridge, multiple species of oak (e.g. Quercus emoryi), juniper (Juniperus spp.), and other woody shrubs typical of the encinal oak community (e.g., Vauquelinia californica) can be found, with denser concentrations occurring along drainages and on northern exposures. 3.2.3.
Xeroriparian
Xeroriparian areas are crossed by the utility corridor along the western flank (or Bajada) of the Santa Rita Mountains. Xeroriparian habitat is characterized by higher biomass and taller‐stature mesquite (Prosopis velutina) and Blue palo verde (Parkisonia floridum) trees than those of surrounding uplands, due to increased soil moisture within low‐lying drainages. 3.2.4.
Mesoriparian
Within the Santa Rita Mountains, the mesoriparian areas contain broadleaf vegetation such as oaks and denser concentrations of riparian grasses, shrubs, and forbs.
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3.3. Soils Soils units within the utility corridor occur are typically associated with mountains and ridgelines; alluvial fans, terraces, sideslopes and floodplains. As the utility corridor extends from east to west, the landforms change from intrusive igneous mountains, hills, and ridges to alluvial fans and terraces. Soil units within the utility corridor exhibit varying degrees of susceptibility to soil compaction associated with construction activities, such as heavy equipment movement. See Table 2 for soil ratings for compaction susceptibility, erosion, and reclamation opportunities within the vegetation communities in the Project area. Soils that are rated as having a high or moderate susceptibility to compaction would likely require decompaction measures to restore or approach the natural soil structure and drainage. A high erosion hazard rating indicates that erosion is very likely and erosion‐control measures are advised; furthermore, these soils may require more extensive mitigation such as pitting on steep slopes and applying tackifier, where appropriate. A moderate erosion hazard rating indicates that some erosion is likely and that erosion control measures may be needed though revegetation treatments would likely stabilize the soil. Table 2.
Soils
Map Unit Name Compaction (Map Symbol) Susceptibility Continental soils, 1 to 10 High percent slopes (CuC) Faraway‐Rock Outcrop complex, 30 to 60 High percent slopes (FrF) Mabray‐Chiricahua‐ Rock Outcrop High association, steep (McF)
Erosion Hazard
Reclamation Opportunity
Low
High
High
Moderate
High
Moderate
Pima clay loam, sandy clayloam, subsoil variant (Pn)
High
Low
Moderate
Sonoita sandy loam, 1 to 3 percent slopes (SmB)
High
Low
Moderate
White House gravelly loam, 0 to 10 percent slopes (WgC)
High
Low
High
Moderate
Low
Moderate
Anthony fine sandy loam, 0 to 3 percent slopes (3)
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Vegetation Community Semidesert grassland Semidesert grassland Semidesert grassland/ encinal oak Sonoran desertscrub/ semidesert grassland Sonoran desertscrub/ semidesert grassland Sonoran desertscrub/ semidesert grassland Sonoran desertscrub/ semidesert grassland
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Table 2.
Reclamation Plan
Soils
Map Unit Name (Map Symbol)
Compaction Susceptibility
Erosion Hazard
Reclamation Opportunity
Vegetation Community Sonoran desertscrub/ semidesert grassland Semidesert grassland Sonoran desertscrub/ semidesert grassland
Comoro soils, 0 to 5 percent slopes (CtB0
Moderate
Low
High
Comoro sandy loam, 0 to 5 percent slopes (CsC)
Moderate
Low
High
Hayhook sandy loam, 1 to 5 percent slopes (35)
Moderate
Low
Moderate
Tortugas‐Rock Outcrop complex, 25 to 60 percent slopes (TrF)
Moderate
High
Moderate
Semidesert grassland
Low
Low
Low
Sonoran desertscrub/ semidesert grassland
Low
Moderate
High
Semidesert grassland
Low
Moderate
Moderate
Encinal oak
Low
High
Low
Low
High
Low
Sonoita gravelly sandy loam, 1 to 9 percent slopes (SoB)
Low
Low
High
Bucklebar‐Sahuarita complex, 0 to 3 percent slopes (8)
Low
Low
Moderate
Riveroad and Comoro soils, 0 to 2 percent slopes (68)
Low
Low
High
Anthony soils (An) Carlampi gravelly sandy loam, 10 to 40 percent slopes (CgE) Chiricahua cobbly sandy loam, 10 to 45 percent slopes (Coe) Lampshire‐Chiricahua association, steep (LcF) Lampshire‐Graham‐ Rock Outcrop association, steep (LgF)
Semidesert grassland Semidesert grassland/ encinal oak Sonoran desertscrub/ semidesert grassland Sonoran desertscrub/ semidesert grassland Sonoran desertscrub/ semidesert grassland
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3.4. Description of Slope The utility corridor lies between 2,725 feet above sea level (asl) near the Santa Cruz River and 5,620 feet asl at Lopez Pass. In general, slopes are mild (0‐8 percent) from the edge of the Santa Cruz Valley across the bajada to the western edge of the foothills of the Santa Rita Mountains. Mild slopes, moderate slopes (8‐15 percent) and moderate‐steep slopes (15‐30 percent) are alternately common in the rolling terrain between Helvetia and just to the east and west of Lopez Pass and eastern terminus of the proposed utility corridor. Steep slopes (more than 30 percent) occur on both sides of Lopez Pass for ⅛ mile to the east and west and along portions of foothills between the ridgeline and the limestone outcropping. These slope categories have been established based upon the slopes upon which typical equipment (road graders, D8) used for reclamation activities can operate.
3.5. Precipitation The average annual rainfall of the northwestern terminus of the utility corridor, between 1981 and 2010, was 11 inches of rain per year. Annual rainfall amounts steadily track with the progressively rising elevation of the bajada, reaching approximately 18 inches per year in the foothills west of Helvetia. Between the first foothills and the ridgeline, the rainfall rises an additional 4 to 22 inches per year. East of the ridgeline, annual rainfall increases more moderately, reaching a maximum level of 23 inches on the southeastern terminus of the utility corridor (NRCS).
4. RECLAMATION PLAN The treatments required specifically for each step of reclamation, with respect to the disturbance type, reclamation opportunity and vegetation community, are presented in this section. Reclamation treatments are physical treatments and activities that will occur throughout each phase of the Project and are presented in detail in Section 4.2, Reclamation Treatments Definitions. These treatments will facilitate resource protection during construction, recovery for areas temporarily disturbed by Project construction, and promote the re‐establishment of vegetation similar in species composition cover and diversity to preconstruction conditions in predetermined areas. All reclamation treatments described in this plan are consistent with the relevant mitigation measures as defined in the CEC and AFEIS. The reclamation treatments as described in the reclamation process below, was created to illustrate appropriate reclamation treatments as they would occur during site preparation, ROW construction, ROW reclamation, and closure reclamation activities. Reclamation treatments, facility features, disturbance types, and vegetation communities have Page 10
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been identified (see Compliance and Monitoring Maps – to be provided later) for each phase as they occur in the reclamation process.
4.1. Reclamation Process The reclamation process defines the four phases necessary and appropriate steps to help ensure for short‐term and long‐term success of the Project: (1) site preparation, (2) ROW construction, (3) ROW reclamation (temporary disturbance), and (4) closure reclamation (permanent disturbance). 4.1.1.
Phase 1 – Site Preparation
Site preparation treatments are implemented prior to vegetation clearing or grading and are intended to minimize disturbance during the construction phase. ROW preparation includes general site preparation involving surveying and flagging of the ROW boundaries and construction areas. Also included is the identification of storage areas for plant salvage or plant material that can root and start new plants (i.e., cactus pads or segments) and soil materials. Preconstruction treatments focus on protection of sensitive areas and resources identified for preservation. Temporary storage areas (location and storage methods/care) for salvage plants are to be determined per compliance monitor or after the compliance plan finalization. Treatments during site preparation include: 4.1.2.
Vegetation avoidance/preserve in place Weed plan implementation (existing noxious weed removal in ROW) Plant salvage Phase 2 – ROW Construction
ROW construction treatments include moving equipment into the ROW for earthwork, cutting vegetation for overland drive and crush, and adhering to requirements and measures that reduce disturbance during transmission line and water pipeline construction. Disturbance related to Project construction may begin after all ROW preparation and preconstruction treatments have been completed. Treatments during ROW construction may include:
Weed plan implementation (travel management and wash stations as appropriate) Overland drive and crush (clear vegetation) Tree cutting Topsoil/Seedbank segregation Tree pruning
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4.1.3.
Reclamation Plan
Phase 3 – ROW Reclamation
The ROW reclamation phase includes treatments that are applied immediately after the facilities have been installed. This phase comprises the majority of treatments until ROW Closure – Phase 4 (see Section 3.1.3). Temporary construction disturbance areas include work areas, laydown areas, spur roads or other temporary access roads and construction yards. Key treatments include decompaction or seedbed preparation, where appropriate, replacing stockpiled topsoil/seedbank over disturbed areas of the ROW, restoring pre‐existing contours, installing temporary or permanent erosion control devices and BMPs (i.e., water bars/slope breakers), and seeding. The reclamation treatments described below would be applied to temporary disturbance area, as described in Table 3 (located in Section 4.1.4). Treatments during ROW reclamation could include: 4.1.4.
Weed plan implementation (travel management, wash stations, adaptive management) Salvage (replanting salvaged plants) Off‐road vehicle deterrent (where applicable) Recontouring (earthworks) Ripping/scarifying Imprinting (pock marking, pitting) Seeding Vertical mulch Permeon™ (or equivalent) Mulch and tackifier Signage Phase 4 – Closure Reclamation
Closure reclamation refers to reclamation treatments that would occur within the utility corridor upon the decommissioning of the Rosemont Copper Project at the end of the life of the project. At that time, if the agencies/regulators require the removal of the transmission line, water pipeline (including booster stations), and access road, reclamation treatments would be implemented to reclaim the areas in which these facilities were located. Key treatments would include restoring any pre‐existing contours, installing permanent erosion control structures and BMPs (i.e., water bars/slope breakers), and establishing native vegetation. These reclamation treatments would be applied to the permanent disturbance types identified in Table 3. Phase 4 Closure Reclamation treatments are not depicted on the reclamation mapping at this time and would be developed when closure of the mine occurs. Specific treatments that would be implemented during this phase could include:
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Weed plan implementation (travel management, wash stations, weed control) Off‐road vehicle deterrent Recontouring (earthworks) Ripping (specifically for the access road) Imprinting (pock marking, pitting) Seeding Vertical mulch Permeon™ (or equivalent) Mulch and tackifier Signage
Table 3.
Disturbance Types Associated with the Utility Corridor Permanent
Temporary
(Reclamation to be completed during closure reclamation)
(Reclamation to be completed during ROW reclamation)
Structure work area
Wire‐pulling and tensioning sites, wire‐splicing sites, construction yards
Structure base
Pipeline ROW
Pump stations
*
Construction Component
Pipeline storage yards Existing roads (no improvement) Existing access road (with improvements) Switchyard New access road (transmission line spur roads) New access road (pipeline)
*Existing roads that require no improvement for the utility corridor will not be reclaimed during closure reclamation (i.e., Santa Rita Road).
4.2. Reclamation Treatments Definitions 4.2.1.
Weed Plan Implementation
Refer to the Rosemont Noxious Weed and Invasive Species Management Plan for specific mitigation measures to implement where noxious weeds have been Page 13
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identified as well as preventative measures to be implemented to prevent the spread of noxious weeds during construction and reclamation phases. When control measures have been implemented for the site preparation phase, subsequent treatments for ROW preparation may proceed. Preventive measures, typically wash stations, can be used to preclude the offsite transportation of seed or plant parts if equipment is working in areas of weed infestation. If treatment is determined to be unsuccessful during the reclamation phase, adaptive management methods will be implemented to address any occurrences of noxious weeds (i.e., alternative treatment prescription). 4.2.2.
Vegetation Avoidance/Protect in Place
Vegetation avoidance areas would be created to preserve pockets of existing vegetation to the degree possible and as illustrated on the Utility Corridor Compliance and Mitigation Maps (to be developed). Riparian areas or sensitive plant specimens (i.e., saguaro) would be examples of this type of treatment. The Pima pineapple cactus (Coryphantha scheeri var. robustispina) is an example of a sensitive plant species that should be avoided, where possible. Preserve‐in‐place areas include the preservation of existing vegetation to the degree possible, when screening of the proposed Project is desired to reduce visual impacts and/or mature plant specimens are present to enhance habitat recovery (reclamation). Other eligible specimens would include mature trees, sagebrush, succulents, or diverse vegetation groupings that would provide seed and a microclimate for seedling germination along edges of the ROW. Flagging or fencing of specimens to be preserved should be done before ground is disturbed. The construction contractor and Rosemont’s monitors (to be determined) will ensure construction activities will not disturb the specimens. 4.2.3.
Plant Salvage
Within known ranges of the lesser long‐nosed bat or cactus ferruginous pygmy‐owl, qualifying paniculate agave plants (Agave palmeri) and saguaro cacti (Carnegiea gigantea) that cannot be avoided will be salvaged. Paniculate agave plants and saguaro cacti that qualify for salvage must be (1) currently in a healthy condition, as determined by the reclamation subcontractor, (2) agaves must not possess flower stalks, and (3) saguaros must be less than 15 feet in height. The Pima pineapple cactus (Coryphantha scheeri var. robustispina) should be avoided to the extent possible, but specimens that cannot be avoided should be transplanted within the utility corridor into a suitable habitat and watered for the first few months followed by regular monitoring. The construction contractor shall identify with flagging tape all paniculate agaves, saguaros, and other succulents and cacti that qualify for salvage, marking the north orientation for cactus only. A list describing quantity and species of plants to be salvaged will be forwarded by the construction contractor to Rosemont upon completion of reclamation activities. Salvaged plants will be transplanted out of Page 14
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harm’s way, in designated areas within the ROWs, by the construction contractor (or reclamation subcontractor) and approved by the Compliance Inspection Contractor, as described below. 4.2.4.
Overland Drive and Crush
Overland drive and crush is a construction technique that minimizes surface disturbance in temporary work areas but allows for access and construction activities to commence. The implementation of this technique minimizes disturbance to the soil structure and seed bed and reduces potential erosion. Vegetation is crushed by the equipment, but not cropped. Soil is compacted, but no surface soil is removed. Examples may include tensioning and pulling areas, tower pad sites, overland access to regeneration sites, and spur roads to towers. 4.2.5.
Tree Cutting
Tree cutting consists of cutting trees off at or near ground level. This practice does not shred the tree, but removes the trunk and stems as one unit. In some cases, the tree will be moved to a temporary storage area so that they may be later be used as a source of vertical mulch or as OHV deterrents. Per direction of the guiding agency or Rosemont’s monitors, trees will be cut such that stumps will be four inches or less in height. In some cases, vegetation shredding may occur in conditions where tree cutting is not feasible. Vegetation shredding involves the removal of brush and occasionally small trees by the use of a tractor‐mounted flail or blade that shreds plants to the ground or to the desired height. This practice produces mulch made of leaves, pieces of branches, and woody fiber. Plants with an apical meristem in the root crown can grow back after being shredded. Debris from vegetation shredding may be stored and used for vertical mulch during the reclamation phase. 4.2.6.
Topsoil Segregation/Seedbank Preservation
Topsoil segregation includes the separation of topsoil from subsoils (if subsoils are disturbed and, specifically, during trenching for the pipeline) which contains organic material, including the seeds of plants growing on the site, to be set aside for post‐ construction replacement. The construction contractor is to conduct topsoil salvage, and include all rocks and vegetation as vertical mulch. The depth at which topsoil separation should occur will be dependent on the soil type within which the reclamation activity will occur and will be discussed and approved by the reclamation subcontractor. This topsoil should be labeled as such and protected from erosion and inadvertent use as fill. Topsoil shall never be mixed with subsoil. When stockpiled, topsoil shall be tackified with water to a 2‐inch wetting depth to minimize erosion. Overall handling should be kept to a minimum. Separation between salvaged topsoil and subsoils will always be maintained. Seed bank preservation consists of removing and storing the top layer of soil containing organic material including the seeds of plants growing on and adjacent to the site for the entire width of the work area. After the subsoil is replaced in the trench, the Page 15
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topsoil is spread over the subsoils and the top layer of soil containing the seed bank is spread over the area from which it was removed to provide an indigenous seed source. 4.2.7.
Tree Pruning
Tree pruning consists of trimming tree branches. This practice does not cut down the tree, but leaves it intact. Trees that are not directly in the ROW or identified for removal (see Section 4.2.5, Tree Cutting) may be pruned to meet construction, operation, and maintenance clearance requirements along the ROW. Debris from pruning may be stored and used for vertical mulch during the reclamation phase. This practice is used to preserve seed sources as close to the ROW as possible to facilitate natural reclamation processes. This technique also is used for portions of the ROW that are visible from key viewpoints to minimize or reduce anticipated visual impacts. Tree pruning locations are to be marked on the Utility Corridor Compliance and Mitigation Maps (to be developed). 4.2.8.
Off�road Vehicle Deterrent
Operation of off�highway vehicles (OHV) can cause mechanical damage to stabilization structures and soils and can cause mortality to plants reoccupying the ROW. Limiting OHV access to the portion of the Project area that is designated for access and prohibiting it in the reclamation areas will facilitate reclamation success. Measures to control OHV and other unauthorized vehicle use of the ROW will be determined in consultation with the USFS and Arizona State Land Department prior to the start of construction and closure activities and potentially depicted on the Utility Corridor Compliance and Mitigation Maps (to be developed). OHV deterrents may include the installation of signs, fences with locking gates, selectively placed boulders, and/or placement of vertical mulch and heavy woody material resulting from the clearing of the ROW. 4.2.9.
Recontouring (earthworks)
Recontouring occurs after a hill or slope is cut or removed to enable construction. Earthmoving equipment replaces the removed material as close to the preconstruction contour as possible to restore the visual quality and provide stability to the slope. This activity will occur throughout the Project, to the maximum practicable extent. Permanent erosion and sediment control measures, such as waterbars or diversion terraces, will be installed at this time. Recontouring will be determined in consultation with the USFS and Arizona State Land Department prior to the start of construction and potentially depicted on the Utility Corridor Compliance and Mitigation Maps (to be developed).
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4.2.10. Ripping Ripping results from a tractor dragging a bar with metal teeth (rippers) to incise (rip) the soil. Ripping loosens compacted soils to improve hydrologic function and provides a catchment for native seeds blown into the area, as well as seeds that are disbursed mechanically. The depth to which a soil is ripped depends on whether or not there is subsoil present that should not be mixed with shallow soil and per the requirements for native seeds in the area. Ripping will occur where Rosemont’s monitor or an agency representative deem that construction has resulted in compacted soils. The Utility Corridor Compliance and Mitigation Maps (to be developed) depict areas where existing soils are susceptible to compaction and, therefore, an assessment should occur before reseeding efforts commence. 4.2.11. Imprinting (pock marking, pitting) Imprinting creates indentations in the ground to collect runoff and precipitation and possibly organic material and plant seed. The practice creates a microhabitat for plant establishment on soils that are difficult to revegetate, such as clays or on slopes that are too steep to rip or scarify. Imprinting is also a technique used to increase water infiltration and retention, where needed. The practice of imprinting also reduces the occurrence of wind and water erosion. The treatment will be applied in a non‐directional pattern that will not result in furrows, which would channel runoff. Areas for potential Imprinting will be determined in consultation with CDM Smith and mapped on The Utility Corridor Compliance and Mitigation maps as appropriate. 4.2.12. Seeding Seeding involves planting new seed of indigenous native species to establish desired vegetation within affected vegetation communities. Seed mixtures will be based on vegetation communities described in Section 3.2 of this plan and per the agencies, where available. The seed mixes should be based on seed availability, viability, and relate to the location of the subject ROW, if possible. Seeding should be implemented where local conditions are conducive to support seed germination and growth. Seeding shall be repeated if a satisfactory stand is not established, as determined by the authorizing agency upon evaluation after the second growing season. Final seed mixes, application methods, and rates will be determined in consultation with the appropriate agencies and modified during reclamation plan finalization. 4.2.12.1. Seed Mixes Sonoran Desertscrub/Semidesert Grassland
Prickly pear (Opuntia spp.) Littleleaf paloverde (Parkisonia microphyllum) Velvet mesquite (Prosopis velutina) Page 17
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Catclaw acacia (Acacia greggii) Four‐wing Saltbush (Atriplex canescens)
Encinal Oak
Sotol (Dasylirion Wheeleri) Beargrass (Nolina microcarpa) Emery oak (Quercus emoryi) Skunkbush sumac (Rhus trilobata) Desert hackberry (Celtis pallida)
Mesoriparian
Seep willow (Baccharis salicifolia) Emery oak (Quercus emoryi) Skunkbush sumac (Rhus trilobata)
4.2.13. Vertical Mulch Materials, including dead plants, cut plants, and rocks are to be temporarily set aside during ROW preparation (i.e., tree cutting and pruning) so that they may be shredded or otherwise placed on the soil surface (post‐construction) to increase fertility, provide microclimates for seed to germinate and stabilize soil. Large rocks and boulders shall also be removed to the side for post‐construction use. Care should be taken to prevent the disturbance of the natural patina or desert varnish of these rocks. Rocks larger than 6 inches can be removed and stockpiled outside the disturbance areas (within the ROW). If an outcrop of boulders will be disturbed, some specimens may be windrowed, as recommended by the agency representatives or Rosemont’s monitor(s). Vertical mulch temporary storage areas should be located near the Project area within the ROW, but separate from the topsoil and subsoil storage. Project locations near sensitive viewers should locate windrowed mulch in a less visible area, where possible. Rock Mulch may be required on the steepest slopes. Materials, including dead plants, cut plants, and rocks from noxious weed infested areas will not be used for vertical mulch. 4.2.14. Permeon™ (or equivalent) Permeon™ is an artificial desert varnish that reproduces natural colors similar in appearance to aged desert varnish in a short period of time and is permanent. It is nontoxic to plants and animals. Depending upon visual contrast after construction, Permeon™ may be required on rock outcroppings. Refer to the Visual Protection Plan regarding monitoring of post‐construction visual conditions. Application rates and color tint will be site specific and may require both a blanket application and spot treatments depending on the adjacent natural landscape. The product is Page 18
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applied via backpacks or a truck‐mounted sprayer, if access to the area adjacent to the reclamation site remains open. Product application may be necessary for large boulders that have been windrowed, and application would occur after they have been replaced, including any tool marks on boulders as recommended by the construction contractor. Application rates and techniques will be determined by the construction contractor and/or USFS landscape architect. 4.2.15. Mulch and Tackifier Mulch usually consists of shredded plant material or straw, but also includes wood fiber, paper mulch, or biodegradable erosion mats. Straw mulch may be used as an alternative to vertical mulch when vertical mulch is not available or will not provide adequate coverage in areas that will not be seeded. The use of tackifiers or erosion blankets maybe a less expensive alternative to straw mulch in areas that require seeding or steep slopes (10‐33%). Straw mulch or other alternative mulches should be weed free as specified in the noxious weed and invasive species management plan. Location, need, and type of mulch will be determined in consultation with the appropriate agencies and Rosemont Copper prior to construction. Specific locations of mulching and tackier treatments will be depicted on the the Utility Corridor Compliance and Mitigation Maps (to be developed). 4.2.16. Signage Reclamation areas will require informational signs pertaining to reclamation efforts in order to prevent further disturbance by humans within these recovering areas. All reclamation areas, including non‐permanent access roads that are to be obliterated, will have signs installed at appropriate intervals to deter vehicular damage to the site. Any public or private property structures removed during preconstruction – such as fences, gates, or driveways – will be confirmed as being restored during this phase.
5. RECLAMATION SUCCESS STANDARDS, MONITORING, AND SITE RELEASE Reclamation success standards for the utility corridor will be developed in coordination with the appropriate agencies and Rosemont Copper upon approval of this plan. In addition, monitoring protocol to determine site release will also be coordinated with the agencies and Rosemont Copper and will be included in the final Reclamation Plan for the overall Project.
References: Arizona Land Resource Information System. 2010
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Brown, D.E. 1994. Biotic Communities Southwestern United States and Northwestern Mexico.University of Utah Press. Natural Resource Conservation Service. Geospatial Data Gateway, accessed 2013 Pima County Regional Flood Control District. Regulated Riparian Habitat Mitigation Standards and Implementation Guidelines - Supplement to Title 16 Chapter 16.30 of the Watercourse and Riparian Habitat Protection and Mitigation Requirements Ordinance No. 2010 FC5 November 2011 USDA. Santa Rita Experimental Range Digital Database: User’s Guide. 2002
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