Gemini Solar Project Decommissioning and Site Reclamation Plan

Decommissioning and Site Reclamation Plan

Gemini Solar Project BLM Case No. N-84631

December 2019

Decommissioning and Site Reclamation Plan

Gemini Solar Project BLM Case No. N-84631

Submitted to: United States Department of the Interior Bureau of Land Management Southern Nevada District Office Las Vegas Field Office 4701 N. Torrey Pines Drive Las Vegas, NV 89130

Submitted by: Solar Partners XI, LLC 1044 10th Avenue Redwood City, CA 94063

Prepared by: EPD Solutions, Inc. 2030 Main Street, Suite 1200 Irvine, CA 92614

Urban Planning ■ Due Diligence ■ Entitlements ■ CEQA/NEPA ■ Development Services ■ Management ■ Public Outreach 2030 Main Street, Suite 1200 ■ Irvine, Calif. 92614

949.794.1180 ■ [email protected]

mailto:[email protected]

TABLE OF CONTENTS

Acronyms and Abbreviations.......................................................................................................... iii

1 Introduction................................................................................................................................. 1

1.1 Background .................................................................................................................................. 1

1.2 Objective ....................................................................................................................................... 1

2 Project Description..................................................................................................................... 3

2.1 Project Location and Setting ...................................................................................................... 3

2.2 Structures and Facilities ............................................................................................................. 3

3 Baseline Site Conditions........................................................................................................... 6

3.1 Introduction ................................................................................................................................. 6

3.2 Land Use....................................................................................................................................... 6

3.3 Topography & Soils .................................................................................................................... 6

3.4 Climate.......................................................................................................................................... 6

3.5 Vegetation .................................................................................................................................... 7

4 Decommissioning Methods ................................................................................................... 10

4.1 Overall Strategy......................................................................................................................... 10

4.2 Pre-demolition Activities ......................................................................................................... 11

4.3 Decommissioning Tasks........................................................................................................... 11

4.4 Hazardous Waste Management.............................................................................................. 15

4.5 Worker Safety ............................................................................................................................ 16

5 Reclamation and Revegetation Methods............................................................................. 17

5.1 Overall Strategy......................................................................................................................... 17

5.2 Site Preparation ......................................................................................................................... 18

5.3 Plant Materials........................................................................................................................... 19

5.4 Seeding Methods and Schedule .............................................................................................. 20

5.5 Reclamation and Revegetation Site Maintenance................................................................. 21

5.6 Success Criteria.......................................................................................................................... 21

5.7 Monitoring, Remediation, and Reporting ............................................................................. 21

Gemini Solar Project – December 2019 i

5.8 Adaptive Management............................................................................................................. 22

6 Financing of Decommissioning and Reclamation............................................................. 24

7 References.................................................................................................................................. 25

Appendices

Appendix A Project Design Drawings

List of Tables

Table 1 Vegetation Communities ........................................................................................... 7 Table 2 Decommissioning Waste and Waste Management.............................................. 16 Table 3 Restoration Performance Targets ........................................................................... 21

List of Figures

Figure 1 Project Location Map.................................................................................................. 2 Figure 2 Vegetation Communities ........................................................................................... 8

Gemini Solar Project – December 2019 ii

ACRONYMS AND ABBREVIATIONS

BLM Bureau of Land Management

BMPs best management practices

DC direct current

gen-tie generation tie

I-15 Interstate 15

kV kilovolt

LADWP Los Angeles Department of Water and Power

MW megawatts

MWac megawatt alternating current

NRCS Natural Resources Conservation Service

O&M operation and maintenance

Project Gemini Solar Project

PV photovoltaic

ROW right-of-way

USDA United States Department of the Interior

Gemini Solar Project – December 2019 iii

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Gemini Solar Project – December 2019 iv

DECOMMISSIONING AND SITE RECLAMATION PLAN Introduction

1 INTRODUCTION

1.1 BACKGROUND Solar Partners XI, LLC (Applicant) proposes to develop the Gemini Solar Project (Project) on approximately 7,100 acres (2,873 hectares) of public lands administered by the United States Department of the Interior, the Bureau of Land Management (BLM), in unincorporated Clark County, approximately 33 miles (53 kilometers) northeast of Las Vegas, Nevada (Figure 1).

This Decommissioning and Site Reclamation Plan (Decommissioning Plan) describes the Applicant’s decommissioning and site reclamation strategy for the Project area after the solar generating facility permanently ceases operation. Permanent closure would occur as a result of facility age, damage beyond repair to the facility, economic conditions, or other reasons. The Decommissioning Plan would be reviewed at least 5 years prior to planned permanent closure and a Final Closure Plan would be prepared. The right-of-way (ROW) requested from the BLM is anticipated to be at least 30 years in duration. The ROW may, if granted, be extended, subject to the discretion of the BLM. The extension of the ROW may be subject to additional review under the National Environmental Policy Act.

The Decommissioning Plan addresses dismantling and removal of Project components and reclamation of areas disturbed over the life of the Project. Reclamation would primarily be accomplished through revegetation. Reclamation of areas that would be temporarily disturbed during Project construction are addressed in a separate Site Restoration Plan (Phoenix Biological Consulting, 2019). Invasive weeds in the Project area would also be controlled throughout the life of the Project in accordance with the Site Restoration Plan. This Decommissioning Plan supplements the Site Restoration Plan. Together, the two documents describe the overall approach to vegetation management, weed management, and site closure and reclamation to be implemented over the life of the Project.

1.2 OBJECTIVE The objective of Project decommissioning and reclamation is to remove the installed power generation equipment and return the Project site to 70 percent of the cover, density, and species richness of a reference site or baseline, with no increased cover, density, or species richness of non-native species compared with a reference site or baseline, in accordance with the Site Restoration Plan standards.

Gemini Solar Project – December 2019 1

DECOMMISSIONING AND SITE RECLAMATION PLAN Introduction

Figure 1 Project Location Map

Sources : (Esri, 2017) (Louis Berger Group, 2018) (USGS, 2017) (The National Map and USGS, 2017) (Ventyx, 2010) (Tele Atlas, 2010a) (Tele Atlas, 2010b)


DECOMMISSIONING AND SITE RECLAMATION PLAN Project Description

2 PROJECT DESCRIPTION

2.1 PROJECT LOCATION AND SETTING The Project site is situated immediately south of the Moapa River Indian Reservation and less than 0.5 (0.8 kilometer) southeast of Interstate 15 (I-15), off Valley of Fire Road, within the Piute Point and Dry Lake United States Geological Survey 7.5-minute topographic quadrangles. The Project is located within Mount Diablo Meridian, Nevada, T.17S., R.64E., secs. 10-15, 25, and 36; T.17S., R.65E., secs. 7-9, 16-21, 28-33; T.18S., R.64E., secs. 1 and 2; and T.18S., R.65E., secs. 4-5.

2.2 STRUCTURES AND FACILITIES

2.2.1 Solar Arrays and Ancillary Facilities The Project includes the construction, operation, maintenance, and decommissioning of an approximately 690-megawatt (MW) alternating current (MWac) photovoltaic (PV) solar project and ancillary facilities on approximately 7,100 acres (2,873 hectares). A larger area encompassing 10,670 acres (4,318 hectares) was surveyed in order to define alternative configurations of approximately 7,100 acres (2,873 hectares) that reduce environmental effects. The solar array areas are divided into development areas, labeled A through G.

The primary access road for the Project during both construction and operation would be Valley of Fire Road. Project components include on-site, off-site, and temporary facilities needed during Project construction. The major on-site facilities are comprised of solar array blocks, substations, and operation and maintenance facilities. Each array block would have an integrated battery energy storage system, inverters, and medium voltage transformers. Electricity generated by the Project would be interconnected to the NV Energy transmission system via overhead generation tie (gen-tie) lines extending from the Project substations to NV Energy’s Crystal Substation (N-74575), located less than 4 miles (6 kilometers) west of the Project. The proposed gen-tie lines would consist of a 230 kilovolt (kV) circuit for delivery of 440-MW to NV Energy Balancing Authority (at Crystal Substation) and a 500 kV circuit for delivery of 250-MW to the Los Angeles Department of Water and Power (LADWP) 500 kV transmission line (N-10683) at the Harry Allen Substation connected through Crystal Substation. The proposed on-site facilities include 34.5 kV overhead and underground collector lines, a 2-acre (0.8-hectare) operation and maintenance (O&M) facility, three substations, internal access roads, access roads along gen-tie lines, a perimeter road, perimeter fencing, water storage tanks for fire protection, drainage control features, and improvements to the existing NV Energy facilities to support interconnection. During construction and operations, water could be obtained through the purchase of an existing appropriation that is accessed



through a new well on the Project site, a permanent water pipeline from the Moapa Paiute Travel Plaza, or via trucking water onto the site.

2.2.2 Construction of the Solar Field The Applicant would utilize multiple methods of site preparation. Mowing, and drive and crush would occur on approximately 4,923 acres (1,992 hectares) of the development area and traditional development methods (“disk and roll”) would be used for the remaining 2,139 acres (866 hectares) of the Project site.

Areas constructed through mowing of vegetation would minimize the areas of direct vegetation removal, thereby maintaining the vegetation community and topsoil seed bank for future regrowth and minimize weed growth. Drive and crush would involve equipment driving over and crushing vegetation, which would be allowed to regrow following construction. The root balls and seed bank would likely be maintained. Areas of the solar array subject to mowing or drive and crush would be designed and constructed differently from the areas cleared using traditional methods. Traditional methods include “disk and roll,” where the vegetation is crushed and mixed into the soil using deep disking, then the soil is compacted so that construction equipment can safety traverse the site to construct the solar arrays and infrastructure. The method does not require grading; however, soils are disturbed, root crowns are buried, and the typical dominant desert vegetation (creosote and white burrobush) do not grow back due to the level of compaction of the soils. Under this traditional method of construction, stormwater retention facilities may be required, and periodic erosion repair is needed in the solar array development areas. Soils are compacted, tackifiers are applied, and weeds are managed with herbicides.

Vegetation in the mowed portion of the Project would be maintained at a height of 24 inches (61 centimeters) but no less than 18 inches (46 centimeters) where justified, during both construction and operation.

The development methods are intended to minimize earth movement and preserve existing runoff patterns to the greatest extent possible when initially constructing the solar facility. Stormwater drainage would flow through the site. In areas constructed using traditional methods, isolated grading is proposed at drainage washes along the alignment of the wash to create protective berms and smooth isolated bumps and dips. No topsoil would be stripped or otherwise segregated. Major drainage areas would be avoided. Fugitive dust would be controlled in accordance with a plan as required by the Clark County Department of Air Quality.

The Applicant construction and site preparation activities would be designed to maintain existing vegetation to the greatest extent possible. Areas containing the array blocks and other infrastructure, such as access roads, would be cleared to the soil and vegetation regrowth is not expected. At select locations on the Project site, removal of vegetation and cut-and-fill would be required to smooth out isolated surface irregularities and to remove oversize rocks.



The staging areas, road corridors, building and substation locations, and areas for other infrastructure would be cleared and graded. Rocks or boulders removed from the array areas would be used as fill in other areas of the site.

2.2.3 Vegetation Management The vegetation on the site consists of creosote-white burrobush (Larrea tridentata-Ambrosia dumosa) shrubland alliance, interspersed with catclaw acacia (Acacia greggii [Senegalia greggii]) shrubland alliance (Desert wash scrub) within the braided ephemeral drainage channels that traverse the site. The northwestern portion of the site contains a mixture of creosote-white burrobush, big galleta grass (Pleuraphis rigida), and shadscale shrubland (Atriplex confertifolia) herbaceous alliances (Phoenix Biological Consulting, 2018a). The Site Restoration Plan (Phoenix Biological Consulting, 2019) identifies specific techniques for vegetation management during operation of the facility.

During operation, vegetation would be allowed to re-grow within the solar array areas and outside of access and maintenance roads. Vegetation would not likely regrow in areas constructed using traditional methods. Motorized mowing equipment would not be used in mowed areas once tortoises are reintroduced to the solar field. Trimming would only occur with hand tools that can be mechanical or motorized. Trimming would only occur in the solar array areas where vegetation can affect the panels, equipment, or access. In areas constructed using mowing techniques, vegetation would be maintained no lower than 18 inches (46 centimeters), but generally 24 inches (61 centimeters).


DECOMMISSIONING AND SITE RECLAMATION PLAN Baseline Site Conditions

3 BASELINE SITE CONDITIONS

3.1 INTRODUCTION This section describes the baseline site conditions. Once the solar field is decommissioned, the goal is to generally restore the land to the baseline conditions that were present before the development of the Project.

3.2 LAND USE The Project area is less than 0.5 mile (0.8 kilometer) east of I-15, an interstate highway that connects Las Vegas with Salt Lake City, and the site is bisected by Valley of Fire Road. The Project ROW is surrounded by lands administered by the BLM on the east, south, and west, and by the Moapa River Indian Reservation on the north.

Other nearby features include:

• Power transmission lines, generally running parallel to I-15 • Desert National Wildlife Refuge Complex, 8 miles (13 kilometers) northwest • Valley of Fire State Park, 7.6 miles (12 kilometers) east

3.3 TOPOGRAPHY & SOILS The topography of the Project site is relatively flat, with elevations ranging from approximately 2,045 to 2,475 feet (623 to 754 meters) above mean sea level, sloping from the northwest corner of development area A to the southwest corner of development area D. According to the USDA Natural Resource Conservation Service (NRCS) online Web Soil Survey, the Gemini Project Action Area consists of nine soil types: (1) AOB - Arada fine sand, gravelly substratum, (2) ASC - Arada fine sand, hardpan variant, (3) BD – Badland, (4) BHC – Bard gravelly fine sandy loam, (5) BOB – Bard-Rough broken land association, (6) Gs – Glendale loam, (7) MOB – Mormon Mesa fine sandy loam, (8) SP – Spring silty clay loam, and (9) THB – Tonopah gravelly sandy loam (USDA NRCS, 2018).

3.4 CLIMATE The climate in this region is characterized by an arid environment with low humidity and sporadic rainfall, strong fluctuations in daily temperatures, hot summers and cold winters, and generally clear skies. Rainfall averages 4 to 8 inches (10 to 20 centimeters) with a mean annual temperature between 60 to 70 degrees Fahrenheit (15.6 to 21.1 degrees Celsius).



3.5 VEGETATION

3.5.1 Vegetation Communities Vegetation communities within the Project area were mapped in 2018. Four vegetation communities were observed within the ROW in 2013 (Phoenix Biological Consulting, 2018a). Vegetation communities are presented in Table 1and shown on Figure 2, and summarized below.

Table 1 Vegetation Communities

Vegetation Community Total Acreage in Study Area (hectares)

Proportion of the Study Area

Shadscale Shrubland Alliance 419.4 (169.7) 5.9%

Big Galleta Herbaceous Alliance 73.1 (29.6) 1.0%

Creosote-White Burrobush Shrubland Alliance 6,534.7 (2,644.5) 91.9%

Catclaw Acacia Shrubland Alliance 77.6 (31.4) 1.1%

Badlands 8.3 (3.4) 0.1%

TOTAL 7,113 (2,879) 100%

3.5.2 Vegetation Communities Descriptions of vegetation communities were included in the Botanical Resources Report prepared for the Project (Phoenix Biological Consulting, 2018a) and are presented below.

Larrea tridentate-Ambrosia dumosa (Creosote-White burrobush) Shrubland Alliance This xerophytic shrubland community is the dominant vegetation alliance of the Mojave Desert. The Creosote-White Burrobush Shrubland Alliance occurs most often on gentle- to moderately-sloped alluvial fans, bajadas, and hills in well-drained, sandy soils that are oftentimes calcareous with a caliche hardpan and/or desert pavement surface. The shrub layer is open and co-dominated by creosote and white burrobush; according to the alliance description in Peterson (Peterson, E, 2008) “cover of either species does not exceed the other by more than twice, and no other species greatly exceeds the cover of both combined.” Other shrubs and sub-shrubs are common and may co-dominate, these may include saltbush (Atriplex spp.), ephedra (Ephedra spp.), cheesebush (Ambrosia salsola), rhatany (Krameria spp.), thornbush (Lycium spp.), indigobush (Psorothamnus spp.), bladder-sage (Scutellaria mexicana), desert senna (Senna armata), and many others.



Figure 2 Vegetation Communities

Source: (Louis Berger Group, 2018) (USDA-FSA-APFO , 2017) (Clark County Nevada GIS Management Office, 2018) (Phoenix Biological Consulting, 2018b)



Atriplex confertifolia (Shadscale) Shrubland Alliance The Shadscale Shrubland Alliance is another common alliance of the Mojave Desert and is typically found in valley bottoms or alluvial slopes on medium- to fine-textured alkaline soils, but can also occur on coarser, calcareous substrates. The shrub layer is open to somewhat dense and dominated or co-dominated by shadscale. Other common shrubs may include other saltbush species, Nevada ephedra (Ephedra nevadensis), rabbitbush species (Ericameria spp.), winter fat (Krascheninnikovia lanata), and thornbush species (Lycium spp.). The herbaceous layer is usually sparse and dominated by grasses.

Pleuraphis rigida [=Hilaria rigida] (Big Galleta) Herbaceous Alliance The Big Galleta Herbaceous Alliance is found in the Mojave Desert on flat ridgelines, lower slopes, and stabilized sand dunes. According to Peterson (Peterson, E, 2008), big galleta “is the sole or dominant graminoid in the herbaceous layer.” Other grasses that may also be present include black grama (Bouteloua eriopoda), fluff grass (Dasyochloa pulchella), red brome, galleta (Hilaria jamesii), sand rice grass (Stipa hymenoides), and more. Shrubs, if present, are usually in low densities.

Acacia greggii [=Senegalia greggii] (Catclaw Acacia) Shrubland Alliance Catclaw acacia is dominant or co-dominant in the shrub canopy with cheesebush, woolly bur-sage (Ambrosia eriocentra), sweetbush (Bebbia juncea), buckhorn cholla (Cylindropuntia acanthocarpa), Virgin River encelia (Encelia virginensis), California ephedra (Ephedra californica), Nevada ephedra, green rabbitbrush (Ericameria teretifolia), eastern Mojave buckwheat (Eriogonum fasciculatum), desert lavender (Condea emoryi), creosote, desert almond (Prunus fasciculata), sugar bush (Rhus ovata), bladder-sage, desert sage (Salvia dorrii), desert senna, Parish viguiera (Bahiopsis parishii), and Mojave yucca (Yucca schidigera). An emergent tree canopy may be present at low cover and could include desert willow (Chilopsis linearis), California or Utah juniper (Juniperus californicus or J. osteosperma), ironwood (Olneya tesota), blue palo verde (Parkinsonia florida), or smoke tree (Psorothamnus spinosus). The shrub layer is under 10 feet (3 meters) tall with an open to intermittent canopy. The herbaceous layer is composed of annuals. This alliance typically occurs in arroyos, channels, and washes in coarse, well-drained soils.

Badlands Badlands are located in the northwest corner of the Study Area along the gen-tie lines. Approximately 49 acres (20 hectares) (less than 1 percent) of the Study Area is badlands. This area is primarily a series of small flat-topped hills with deeply incised drainages between them. Soils are a mixture of clay and caliche that appear red in some areas and are bleached white in others. Vegetation is extremely sparse throughout most of this area, and in some areas, it is completely barren of plant life. Shrubs occur in very low densities and include white burrobush, desert holly, and alkali seepweed.


DECOMMISSIONING AND SITE RECLAMATION PLAN Decommissioning Methods

4 DECOMMISSIONING METHODS

4.1 OVERALL STRATEGY The life of the Project is expected to be at least 30 years. When the Project has reached the limit of utility, it would be decommissioned and the land occupied by Project components would be reclaimed. Reclamation and revegetation would be conducted in accordance with the methods described in Section 5. Project decommissioning would be coordinated with the BLM and would follow a Final Closure Plan to be prepared prior to facility closure. Decommissioned and reclaimed material may be salvaged to offset the costs of reclamation.

Decommissioning activities are expected to involve a similar level of effort as Project construction, requiring an average workforce of approximately 500 to 700 workers, a maximum workforce of 900 workers, and approximately 28 months to complete.

The overall decommissioning strategy would include the following major elements, but may be modified at the time of decommissioning to reflect current best management practices and BLM direction:

• Recycling as much material as feasible in accordance with the Waste and Hazardous Materials Management Plan prepared for operation of the facility

• Removal of all structures and facilities • Removal of foundations to a depth of approximately 3 feet (1 meter) below final grade;

removed foundation material would be demolished and hauled to a permitted facility for disposal

• In-place abandonment of foundations deeper than 3 feet (1 meter) below final grade • Excavation and removal of belowground structures • Removal and salvage of solar array rack posts • Backfilling the voids created by foundation or post removal with native soils • Removal of berm materials and replacement in adjacent, original borrow areas • Remediation of any fuel, lubricant, or hazardous material spills to current regulatory

standards • Abandonment and recontouring of all service roads (except those used to connect existing

roads) where necessary to make surfaces similar with surrounding topography • Adopting a take-back or recycling program for solar panels to ensure collection and

recycling of the panels at the end of their useful life; the Project owner would dismantle the arrays to avoid panel breakage and ship the panels to the manufacturer’s nearest storage facility to be reused or recycled



• Proper handling and disposal of batteries in accordance with the Waste and Hazardous Materials Management Plan

• Minimal recontouring of land surface using standard grading equipment to maximize the likelihood of vegetation recovery over time, and minimize soil erosion, dust generation, and weed invasion

4.2 PRE-DEMOLITION ACTIVITIES Pre-decommissioning activities would consist of preparing the Project area for demolition. A pre-demolition meeting that includes safety and environmental training would be held on-site for pertinent Project staff, all construction personnel, and environmental monitors. The solar power plant would be de-energized and completely disconnected from the substation per the Applicant’s health and safety program procedures. The site also would be surveyed and marked for demolition.

Pre-demolition activities would include removal of products such as diesel fuel, hydraulic oil, lubricants, mineral oil, and other materials to reduce personnel health and environmental risk during decommissioning work. Hazardous materials and petroleum containers would be rinsed clean when feasible and the rinseate collected for off-site disposal. These materials generally would be transferred directly into tanker trucks or other transport vessels and removed from the site at the point of generation to minimize the need for hazardous material and waste storage at the Project site.

Decommissioning operations are assumed to span about 28 months; therefore, fencing, electrical power, and water facilities would be maintained in place and operational to be available for limited use by decommissioning and site restoration workers.

Temporary exclusion fencing would be placed at the direction of cultural monitors to keep construction crews out of sensitive environmental or cultural areas.

Approximately 65 percent of the Project site will be occupied by desert tortoise during operation. Desert tortoise exclusion fencing would be installed around the perimeter of the Project reclamation areas where desert tortoise are located and then the tortoise within the areas would be temporarily relocated outside the fence of the reclamation areas in accordance with the Biological Opinion and the Desert Tortoise Translocation Plan for Project Decommissioning.

4.3 DECOMMISSIONING TASKS

4.3.1 Overview of Tasks Decommissioning activities would involve use of heavy machinery to disassemble and remove buildings and fixtures used during operations. These activities would only occur within existing disturbed areas to the greatest extent possible. Previously undisturbed areas that are inadvertently affected by Project decommissioning activities would require recontouring and



restoration. These areas would be included in the Final Closure Plan, which would include a requirement that areas disturbed during decommissioning be identified and included for restoration.

4.3.2 Demolition of Aboveground Structures Mechanized equipment operated by trained personnel would be used to dismantle each structure or facility. Decommissioning would be undertaken using traditional heavy construction equipment including, but not limited to, front-end loaders, cranes, track-mounted and rubber-tired excavators, bulldozers, and scrapers. Dismantling and demolition of aboveground structures would be followed by concrete removal, as needed, to ensure that no concrete structure remains within 3 feet (1 meter) of final grade (i.e., floor slabs, belowground walls, and footings). Underground utilities associated with aboveground structures would then be dismantled and removed (refer to Section 4.3.3). Excavation and removal of soils would be conducted, as needed (refer to Section 4.3.5), following by final site contouring, as needed (refer to Section 4.3.6).

Photovoltaic Combining Switchgear (PVCSs) would be isolated from the substation using standard lock-out tag-out procedures. It would then be electrically disconnected, unbolted from its foundation, and lifted onto a truck for removal from the site. PV modules would be disconnected from each other and removed from the racks. These modules would be returned to PV manufacturer storage sites or recycling centers. Batteries would be removed and disposed of in accordance with the Waste and Hazardous Materials Management Plan. Direct current string wiring that is connected to the racking would be removed and salvaged. Racks would be disassembled and removed from the site and delivered to recycling centers. Steel posts that support the PV racking system would be pulled out of the ground. Electrical cabling would be disconnected from combiner boxes, inverters, transformers, and overhead transmission poles. Inverter and transformer skids would be electrically disconnected, unbolted, and lifted onto trucks for removal from the site. The supervisory control and data acquisition system would be disconnected, removed, and salvaged by the electrical demolition contractor.

Electrical and mechanical systems would be properly isolated and demolished in the operation and maintenance building. Walls, doors, and windows would be removed and recycled or disposed of at an approved landfill. Parking lot gravel would be loaded into a dump truck and transported off-site. All salvageable parts and parts to be disposed of would be removed from the site. Bathroom facilities provided through use of portable sanitary facilities would be removed by the leasing company. Aboveground foundations would be demolished and the rubble loaded onto dump trucks and transported to the nearest landfill or recycling center.

Dismantled materials would be transported by heavy-haul dump truck to a central recycling/staging area where the debris would be processed for transport to an off-site recycler. A project recycling center would be established to:

• Stage PV panels for transport to an off-site recycler



• Crush concrete and remove support posts and rebar • Stage support posts and rebar for transport to an off-site recycler • Temporarily store and act as a shipping point for any hazardous materials to an approved

treatment, storage, or disposal facility

Limited quantities, if any, of aggregate are anticipated to be used on access roads to ensure surface stability. To the extent required, aggregate surfacing, if present, would be removed. Areas where aggregate surfacing has been removed would be graded to ensure suitable drainage. The removed aggregate would be loaded into a dump truck and the demolition contractor would take ownership of the aggregate for reuse. Site-related fencing, including special status species exclusion fencing, would be maintained until near the end of Project decommissioning (i.e., after initial reclamation efforts have been completed).

Batteries would be removed and recycled or disposed of in accordance with the hazardous materials and waste management component of the Health and Safety Plan.

4.3.3 Demolition of Belowground Facilities and Utilities Belowground facilities would include concrete slabs and footings that would be removed to a depth of 3 feet (1 meter) below grade after final contouring. Concrete slabs include concrete foundations of various Project components, such as substation equipment, BESS, O&M building, Power Conversion Stations, PVCSs, AC collection system poles, and gen-tie poles. Footings include concrete piers (approximately 18 to 24 inches [46 to 61 centimeters] wide) or posts (approximately 6 to 8 inches [15 to 20 centimeters] wide) that would be utilized for the solar panels. Pipelines would be cleaned, closed off, and removed. Rinseate would be temporarily stored on-site prior to transport to an off-site facility for disposal or recycling.

Underground cables would be removed and salvaged, according to BLM requirements. Installations of underground electrical systems are typically trenched to a depth of 3 feet (1 meter) with cables directly buried (i.e., no conduit is used). Underground direct current (DC) cabling from module arrays to combiner boxes and from the combiner boxes to the DC fuse boxes would be removed and salvaged. AC cables from the inverter stations to PVCSs would also be removed and salvaged. Inverters would be removed and salvaged, and the inverter housing and pad would be destroyed.

Removed materials would be excavated and transported to the on-site processing area for processing and transport prior to recycling. Any cavities resulting from structure removal would be backfilled with suitable material of similar consistency and permeability as the surrounding native materials. It would be compacted according to the guidelines for revegetation prescribed by the Reclamation Specialist (refer to Section 5). All Project access roads would be decompacted according to BLM requirements at the time.



4.3.4 Demolition Debris Management, Disposal, and Recycling Demolition debris would be placed in temporary on-site storage area(s) pending treatment at the processing area, and final transportation and disposal/recycling would occur according to the procedures listed below.

Demolition debris and removed equipment would be cut up or dismantled into pieces that can be safely lifted or carried with the on-site equipment. Most glass and steel would be processed for transportation and delivery to an off-site recycling center. Some specific equipment such as PV panels, transformers, and generators may be transported as intact components, or size-reduced on-site with cutting torches or similar equipment.

A front-end loader, backhoe, or other appropriate equipment would be used to crush or compact compressible materials. These materials would be laid out in a processing area to facilitate crushing or compacting with equipment prior to transport for disposal/recycling. Steel, glass, and other materials would be temporarily stockpiled at or near the processing location pending transport to an appropriate off-site recycling facility. Concrete foundations would be removed to a depth of at least 3 feet (1 meter) below final grade. Upon removal of rebar from concrete rubble, the residual crushed concrete may be layered beneath the ground surface to fill cavities, but only at locations that would remain greater than 3 feet (1 meter) below final grade, which would reduce waste volume and transportation requirements.

A full-time crew would be responsible for maintaining site cleanliness during decommissioning. The crew would be responsible for cleaning up micro-trash at temporary facilities as well as at the various work areas. All trash would be collected in containers with secure lids. All hazardous and nonhazardous waste would be stored in appropriate containers for off-site disposal.

4.3.5 Soil Cleanup and Excavation Evidence of the presence of contaminated soil or the release of hazardous materials or wastes observed during decommissioning activities would be reported to the Applicant and the BLM. The need for, depth, and lateral extent of contaminated soil excavation would be evaluated by an environmental professional with experience in contaminated soils investigation procedures. The evaluation would be based on observation of soil conditions and analysis of soil samples after removal of hazardous materials storage areas, and upon closure of the temporary recycling center and waste storage areas used during Project decommissioning. Soil excavation would be conducted to the extent required to meet regulatory cleanup criteria for the protection of soil, groundwater, and surface water resources. If contaminated soil removal occurs, excavations would be backfilled with clean (uncontaminated) native soil of similar permeability and consistency as the surrounding materials, and compacted and revegetated according to the guidelines prescribed by the Reclamation Specialist (refer to Section 5).



4.3.6 Recontouring Minimal recontouring of affected areas of the site would be conducted using standard grading equipment to return the land surface to preconstruction conditions, to the greatest extent possible. Grading activities would be limited to previously disturbed areas that require recontouring. Efforts would be made to minimize disturbance of natural drainage and vegetation. Concrete rubble, crushed to approximately 2 inches (5 centimeters) in diameter or smaller, would be placed in the lower portions of fill areas, at depths at least 3 feet (1 meter) below final grade. Backfill would be compacted by wheel- or track-rolling to avoid over-compaction of soils. Revegetation and habitat rehabilitation would be implemented as prescribed by the Reclamation Specialist (refer to Section 5).

4.4 HAZARDOUS WASTE MANAGEMENT Fuel, hydraulic fluids, and oils would be transferred directly to a tanker truck from the original storage containers. Storage containers would be rinsed and rinseate would also be transferred to tanker trucks. Storage containers would be disposed of properly according to requirements for the handling and disposal of such materials. Any other materials that may be deemed hazardous, such as batteries, would be removed from the site and disposed of according to the hazardous materials handling requirements pertaining to the site. Other items that are not feasible to remove at the point of generation, such as small containers of lubricants, paints, thinners, solvents, cleaners, batteries, and sealants, would be maintained in a secured location with secondary containment, meeting all requirements for hazardous waste storage until removal for proper disposal. All oils would be recycled off-site at an appropriately licensed facility. Site personnel involved in handling these materials would be trained to properly handle them. Containers used to store hazardous materials would be inspected regularly for any signs of failure or leakage.

As part of the preparation for closure, the Spill Prevention, Control, and Countermeasure Plan for the site would be updated to address measures for handling these materials during decommissioning activities. Procedures to minimize the potential for release of contaminants to the environment and contact with stormwater would be specified in a project-specific Best Management Practices (BMP) Plan.

Solid and hazardous waste quantity estimates and management approaches to be adopted during Project decommissioning are provided in Table 2.

Additional hazardous materials may include, but not be limited to, the following:

• Sulfur hexafluoride in switchyard equipment • Diesel no. 2 in generators and fuel pumps (if on-site) • Mineral oil in transformers • Lead solder in solar panels • Batteries



4.5 WORKER SAFETY A site-specific Decommissioning Health and Safety Plan would be prepared to specify requirements for establishing and maintaining a safe working environment during implementation of the planned decommissioning and reclamation activities.

Table 2 Decommissioning Waste and Waste Management

Waste Type Composition Quantity1 Frequency of Generation

Management Approach

Construction Waste (hazardous)

Empty hazardous material containers

1 cubic yard (0.8 cubic meter) per week

Intermittent during decommissioning

Accumulate on-site for up to 90 days. Return to vendor or dispose at permitted hazardous waste disposal facility.

Construction Waste (hazardous)

Solvents, used oil, paint, oily rags

100 gallons (379 liters)

Every 90 days Accumulate on-site for up to 90 days. Recycle or dispose of at permitted hazardous waste disposal facility.

Spent Batteries (universal waste)

Lead acid, alkaline type, or lithium ion

4,000 in 28 months

Intermittent during construction

Accumulate on-site for up to 90 days. Recycle or dispose of in accordance with the law.

Construction Waste (non-hazardous)

Scrap wood, concrete, steel, glass, plastic, paper

20 cubic yards (15 cubic meters) per week

Intermittent Recycle when feasible. Dispose to Class III landfill when not feasible to recycle.

Sanitary Waste (non-hazardous)

Portable chemical toilets, sanitary waste

100 gallons per day (379 liters)

On days of active decommissioning

Pump to tanker truck by licensed contractors, who would dispose of at wastewater treatment plant.

Office Waste (non-hazardous)

Paper, aluminum, food

1 cubic yard (0.8 cubic meter) per week

Intermittent Recycle when feasible. Dispose to Class III landfill when not feasible to recycle.

Note: 1 Calculations estimated from analysis of other solar PV projects and materials generated.


DECOMMISSIONING AND SITE RECLAMATION PLAN Reclamation and Revegetation Methods

5 RECLAMATION AND REVEGETATION METHODS

5.1 OVERALL STRATEGY The goals of site reclamation are to restore the land to pre-project conditions, establish quality habitat for desert tortoise and other fauna, and minimize potential erosion through proper restoration activities and implementation of appropriate BMPs.

The overall reclamation strategy would include the following major elements:

• Rehabilitation and potential revegetation of disturbance areas that would create natural-appearing topography and reduce potential for erosion

• Implementation of a practical revegetation program that would accelerate natural vegetation succession

• Continued implementation of the Site Restoration Plan during Project decommissioning to ensure eradication of non-native species

• Identification of means and methods to minimize long-term maintenance and support requirements, such as irrigation, weeding, or reseeding

• Reduction of visual contrasts between disturbed areas that have been decommissioned and adjacent undisturbed areas

• Habitat restoration to support wildlife breeding and foraging

The following tasks are proposed to implement the reclamation strategy:

• A Final Closure Plan would be prepared and submitted to the BLM for review and approval at least 5 years prior to planned closure. The Plan would include, among other things, timing for seed collection, if deemed necessary, to ensure that sufficient seed stock is available for restoration efforts.

• The ground surface would be recontoured to match the lines and grades of the natural gradient of the surrounding area once areas have been decommissioned and facilities and structures removed. A BMP Plan would be prepared and appropriate BMPs would be implemented to provide an effective combination of erosion and sediment control until revegetation efforts have sufficiently stabilized the soil. It is anticipated that minimal recontouring would be required.

• Applicable areas may be re-seeded with native plant seed, in accordance with the Site Restoration Plan.

• Weed management would be implemented as described in the Site Restoration Plan and Integrated Weed Management Plan unless revised in the Final Closure Plan.



• Wildlife exclusion fences would be removed and the area would be opened to wildlife for use. No restoration work would occur outside of fenced areas without the presence of an Authorized Biologist or Tortoise Monitor.

• Unless revised in the Final Closure Plan, revegetation monitoring would be implemented as described in the Site Restoration Plan to ensure that revegetation efforts are successful. If revegetation does not meet these criteria, remediation measures would be implemented.

• Subject to confirmation in the Final Closure Plan, any and all desert tortoise sign noted during vegetation monitoring events would be recorded and reported.

• It is anticipated that a year after reclamation and revegetation activities are completed, desert tortoise may be allowed to reoccupy the Project site.

Prior to initiating decommissioning activities, the Project owner would contract with a qualified Reclamation Specialist to evaluate and prescribe specific reclamation measures throughout the Project area. The Reclamation Specialist would coordinate with the designated Project Biologist and with the Project owner to ensure that the measures are implemented as written.

5.2 SITE PREPARATION The Applicant does not anticipate substantial grading or soil removal during site reclamation; therefore, measures for topsoil salvage, storage, or replacement are not needed. Any trenches, bores, or other excavations created during decommissioning activities would be backfilled to original grade and recompacted in accordance with accepted engineering practices using native soils and as prescribed by the Reclamation Specialist.

Reclamation work would be determined on a site-by-site basis, based on the advantages and disadvantages of soil treatment or site preparation methods to restore natural contours, protect the site from damage by wind or water erosion, and maximize likelihood of vegetation recovery. Specific site preparation measures would be selected prior to initiation of reclamation work in coordination with BLM reclamation staff.

Soil decompaction can increase soil vulnerability to weeds or erosion, increase dust, or cause further damage to surviving rootstocks that may be present. The Reclamation Specialist would evaluate soil compaction and prescribe no treatment, limited treatment using hand tools, light harrowing or disking with a tractor, or deeper disking or ripping. Where soil decompaction is implemented, follow-up measures to control dust and erosion would also be prescribed.

Surface treatment such as soil imprinting may be prescribed, based on the extent of areas to be reseeded, soil condition, and availability of imprinting or similar equipment. Where decommissioning or prior project-related disturbance resulted in alterations to natural channel morphology or runoff patterns, the Reclamation Specialist would prescribe recontouring or other measures. Any BMP materials to be used at any work site shall be certified weed-free, consistent with the Site Restoration Plan.



Mulch used for erosion control would be produced from native vegetation cleared from the site, where feasible. The Reclamation Specialist may recommend stockpiling the vegetation removed during decommissioning, if any, for replacement onto the site either as crushed mulch, or as “vertical mulch” to reduce sun and wind exposure to the soil surface and germinating plants.

5.3 PLANT MATERIALS The Applicant would re-seed reclaimed areas with a native seed mix, as described in the Site Restoration Plan. The determination whether to re-seed and, if so, seeding rates (i.e., pounds per acre) would be made by the Reclamation Specialist, based on the nature of disturbance, condition of soils, evidence (if any) of re-sprouting from rootstocks, and provisions in the Final Closure Plan. The seed mix would consist primarily or exclusively of native early-successional species. There would be no re-seeding on sites where decommissioning and prior project activities have left sufficient native vegetation in place, or where vegetation has recovered to meet the success criteria listed in Section 5.6.

The Applicant would arrange for adequate seed supplies well in advance of scheduled seeding for each disturbed site. Seed cannot be reliably collected or acquired in any given year due to the unpredictable rainfall and drought conditions throughout the Mojave Desert region. Immediately following notification to the BLM of planned closure, the Reclamation Specialist or Project Biologist would estimate the total number of acres to be reseeded and determine quantities of seed needed. The Applicant would collect seed, or would contract with suppliers or collectors, to acquire and store enough seed for all projected reseeding work. The Reclamation Specialist would be responsible for maintaining a seed inventory.

The seed mix would consist of a selection of native species as listed in the Site Restoration Plan, or according to BLM direction at the time. The preference would be to select early-successional species.

Total seeding rate would be no less than 20 pounds per acre (22 kilograms per hectare). Specific proportions would be based upon seed availability and recommendations of the Reclamation Specialist. Depending on seed availability, other native species occurring on the site or nearby at similar exposure and elevation may be selected to replace those listed above. Any plant material used in revegetation must be locally native and must occur on or near the Project site. All seed to be used in revegetation would originate from the Mojave Desert region of Nevada, at an elevation similar to the Project site. The Applicant would require the supplier to provide location and elevation for each seed lot and would not purchase or use seed originating outside these geographic and topographic boundaries. Any seed from vendors or contracted collectors would be certified weed-free. The Project owner may collect seed on-site or in nearby areas. The collection of adequate seed supplies would likely necessitate repeated visits to any given collection area, depending on seasonality and annual productivity of the target plants. The Project owner would be responsible for acquiring adequate seed to implement this plan.



Seed collections by the Project owner or its contractors or vendors would be made according to the following guidelines:

• Seed collection from plants to be removed or mown for Project construction would be unrestricted.

• Any seed collection on public lands other than the Project site would be performed under authorization from the BLM.

• No more than 40 percent of seeding plants in any collection area (excluding Project disturbance areas) would be harvested. No more than 10 percent of mature seed on any single plant would be harvested.

• Access to collection areas would be via open, designated routes, or on foot; there would be no cross-country vehicle travel.

• Collectors would record and track seed lots, including collection date, collection location, elevation, dominant species at location, stand conditions, test data, bulk weight, and net weight (as pure live seed).

5.4 SEEDING METHODS AND SCHEDULE Seeding methods and schedule would be prescribed by the Reclamation Specialist on a site-by-site basis, in coordination with the BLM. Seeding methods may employ equipment (e.g., seed drill or hydroseeding equipment) for large areas. Some reclamation sites may be small or inaccessible to equipment. In these areas, seed would be broadcast using manually operated cyclone-type bucket spreaders, mechanical seed spreaders, blowers, or rubber-tired all-terrain vehicles equipped with mechanical broadcast spreaders. Seed in the spreader hoppers would be mixed to discourage separation of the component seed types. Where broadcast seeding is employed, seeded areas may be raked or harrowed to cover the seed, at the direction of the Project Reclamation Specialist.

Reseeding would be scheduled to minimize potential seed loss to granivorous birds and small mammals and maximize exposure to seasonal rainfall. Seeding would be done in late summer or early fall to ensure that seed is in place prior to the onset of seasonal rain in late fall or early winter. Later seeding is likely to result in failed germination due to inadequate moisture availability.

Germination and establishment success of seeded plants is not predictable due to the arid climate and variable rainfall within the Project region. Low germination success in the first year following reseeding may be consistent with the goal of this plan (i.e., to prevent or minimize further site degradation) during dry years, when erosion and weed cover are not problematic. However, the Applicant may need to take additional measures to minimize dust generation from sites where adequate plant cover does not reestablish (refer to Section 5.6).



5.5 RECLAMATION AND REVEGETATION SITE MAINTENANCE Reclamation and revegetation sites would not be irrigated. The sites would be monitored for weed presence and abundance, and weed control would be implemented as needed, according to the Project Site Restoration Plan. Additional maintenance activities would consist of erosion control, soil stabilization, or other measures as needed, to be based on the results of monitoring. It is anticipated that a year after reclamation and revegetation activities are completed, desert tortoise may be allowed to reoccupy the Project site.

5.6 SUCCESS CRITERIA Restoration would be considered successful if plant cover, density, and species richness of the dominant native perennial vegetation is equal to or exceeds a designated percentage of the values for these parameters in undisturbed reference areas.

The annual performance targets in Table 3 are recommended to evaluate annual progress towards achieving the final standard. If progress substantially differs from these performance targets, remedial measures could be necessary to bring the Project back on schedule.

Table 3 Restoration Performance Targets

Year Native Perennial

Species Cover

Density of Native Perennial Species

Richness of Native Perennial

Species

Noxious Weed Cover

Recommended Performance Targets

1 10% >100% 70% <2%

2 20% 80% 70% <2%

3 30% 70% 70% <2%

4 40% 70% 70% <2%

5 50% 70% 70% <2%

Final Performance Standard1

6 70% 70% 70% <2%

Note: 1 Depending on conditions that affect seedling germination establishment and growth, achieving

the final performance standard for cover may be less important, if density, species richness and other factors indicate an overall positive upward trend for the Project.

5.7 MONITORING, REMEDIATION, AND REPORTING Following implementation of reclamation measures, each site would be monitored annually to evaluate success, in terms of the success criteria above. Monitoring would continue for a period of no less than 5 years or until the defined success criteria are achieved.



Remediation activities (e.g., additional planting, removal of non-native invasive species, or erosion control) would be performed during the 5-year monitoring period, if necessary, to ensure the success of the reclamation effort. If the site fails to meet the performance criteria after the 5-year maintenance and monitoring period, monitoring and remedial activities would continue on a yearly basis until the criteria are met.

If a fire or flood damages a reclamation site within the monitoring period, the Project owner would be responsible for a one-time planting replacement. If a second fire or flood occurs, no replanting would be required unless the damage is caused by the Project owner’s activity (as determined by the BLM or other firefighting agency investigation).

Throughout the decommissioning phase and for a minimum of 5 years following completion of decommissioning, the Project Biologist and Reclamation Specialist would be responsible for providing annual Closure and Reclamation Progress Reports to the BLM and the United States Fish and Wildlife Service for review and approval. Each annual report would include the following components:

• Brief summary of decommissioning status, with a list of all sites treated or monitored during the preceding year

• Summary of reclamation progress and results since previous report, including a map of all reclamation activity since previous report

• Seed inventory that accounts for materials acquired or used since previous report and materials needed for coming 5-year period

• Summary of monitoring results and completion status for all sites • Recommendations, as applicable, for remedial work such as reseeding, erosion

control, weed control, or other maintenance activity • Representative site photographs • Notation of any other pertinent concerns (e.g., vehicle trespass) • A comparison of annual success criteria with field conditions, identification of any

shortcomings, and recommendations for remedial measures necessary for the success of the revegetation efforts

5.8 ADAPTIVE MANAGEMENT Adaptive management would be implemented in the event of unforeseen or probable but unpredictable circumstances. Adaptive management is defined for the purposes of this plan as a flexible, iterative approach to the long-term management of the site. It would be directed over time by the results of ongoing monitoring activities and direct observation of environmental stressors that are producing adverse results within the site. Adaptive management would include use of monitoring data gathered in the field during the plan to assess the health and vigor of the reclamation sites. Following an event that causes damage to all or part of the site, these data would be used in part to drive management considerations for repair of the damaged



areas. Individual environmental stressors such as flooding or prolonged drought could require additional measures be conducted to ensure success.


DECOMMISSIONING AND SITE RECLAMATION PLAN Financing of Decommissioning and Reclamation

6 FINANCING OF DECOMMISSIONING AND RECLAMATION

As required by the BLM, the Applicant would purchase a performance bond or similar security, which would be issued either by an insurance company or a financial institution to guarantee the satisfactory decommissioning and restoration of the Project site. The bond would be obtained prior to the start of Project construction and would be structured so the funds would be returned to the Project owner upon completion of decommissioning and restoration activities (with an amount held in reserve until restoration monitoring is completed). It would also be structured in such a manner that the BLM would be able access those funds to pay for the decommissioning and restoration of the site, in the event that the Project owner becomes insolvent.


DECOMMISSIONING AND SITE RECLAMATION PLAN References

7 REFERENCES

Clark County Nevada GIS Management Office. (2018). Street Centerline Database.

Esri. (2017). "GIS Vector Data of Major Roads and Highways".

Louis Berger Group. (2018, October). "Gemini Solar Project Elements CAD Datasets".

Peterson, E. (2008). International Vegetation Classification Alliances and Associations Occurring in Nevada with Proposed Additions. Carson City: Nevada Natural Heritage Program,.

Phoenix Biological Consulting. (2018a). Botanical Resources Report.

Phoenix Biological Consulting. (2018b). Vegetation Delineation GIS Dataset.

Phoenix Biological Consulting. (2019). Site Restoration Plan.

Tele Atlas. (2010a, June 30). United States and Canada City Points. Esri® Data & Maps: StreetMap. Redlands, CA, US: Esri.

Tele Atlas. (2010b, June 30). United States and Canada Lakes. Esri® Data & Maps: StreetMap. Redlands, CA, US: Esri.

The National Map and USGS. (2017, December 21). "The National Atlas: Federal and Indian Land Areas". Redlands, CA, US: Esri.

USDA NRCS. (2018). Web Soil Survey. Retrieved from https://websoilsurvey.nrcs.usda.gov/

USDA-FSA-APFO . (2017). Nevada NAIP Imagery. USDA-FSA-APFO Aerial Photography Field Office.

USGS. (2017, August 14). "USGS National Transportation Dataset (NTD) fir Nevada 20170814 State or Territory FileGDB 10.1".

Ventyx. (2010, March 26). "United States Counties". "The Counties Intellegent Map". Boulder , CO, US: Ventyx.


https://websoilsurvey.nrcs.usda.gov

DECOMMISSIONING AND SITE RECLAMATION PLAN

APPENDIX A PROJECT DESIGN DRAWINGS

Gemini Solar Project –December 2019

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Gemini Solar Project Decommissioning and Site Reclamation Plan

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