Project Narrative Report - Sempra US Gas & Power, LLC

Maricopa County Major Amendment Z2013099 Minor Amendment Z2012052 Minor Amendment Z2010073 Special Use Permit Z2009022 Mesquite Solar Energy Project Project Narrative Report Submitted by

December 28, 2013

Mesquite Solar Energy Project—SUP Application

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Table of Contents Page

1.0 Project Name and Location ....................................................................................... 1

1.1 Project Name ................................................................................................... 1

1.2 Location ........................................................................................................... 1

2.0 Purpose of Request .................................................................................................... 2

2.1 Expansion of the Project Site .......................................................................... 2

2.2 Project Benefits ............................................................................................... 2

2.3 Site Suitability .................................................................................................. 2

3.0 Previous Approvals .................................................................................................... 3

3.1 CPA 200005 and SUP Z2000071 (Water Property) ........................................ 3

3.2 CPA 200807 and SUP Z2008066 (Original Site) ............................................. 3

3.3 SUP Z2009022 and Amendments (Original Site) ............................................ 3

3.4 CPA 200910 (Expansion Area)........................................................................ 4

3.5 Other Previous Approvals ................................................................................ 4

4.0 Facility Description .................................................................................................... 5

4.1 Overview ......................................................................................................... 5

4.2 Solar Field ....................................................................................................... 5

4.3 Electrical Collection System ............................................................................ 6

4.4 Substation ....................................................................................................... 6

4.5 Driveways ........................................................................................................ 7

4.6 Drainage Design .............................................................................................. 7

4.7 Grading Design................................................................................................ 8

4.8 Screening Berm and Landscaping ................................................................... 8

4.9 Fencing ............................................................................................................ 9

4.10 Administration Building .................................................................................... 9

5.0 Construction ............................................................................................................. 11

5.1 Project Phases and Schedule........................................................................ 11

5.2 Construction Workforce and Workspace ....................................................... 11

5.3 Site Preparation and Grading Activities ......................................................... 11

5.4 Equipment Installation ................................................................................... 12


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6.0 Operation................................................................................................................... 13

6.1 Operation Workforce ..................................................................................... 13

6.2 Facility Maintenance ...................................................................................... 13

6.3 Site Security .................................................................................................. 13

6.4 Weed Management and Dust Control ........................................................... 13

7.0 Health and Safety ..................................................................................................... 14

7.1 Health and Safety Program ........................................................................... 14

7.2 Fire Protection ............................................................................................... 14

7.3 Emergency Management Plans ..................................................................... 15

8.0 Land Use and Community Resources .................................................................... 16

8.1 Land Use on the Project Site and Surroundings ............................................ 16

8.2 Site Access and County Right-of-Way ........................................................... 17

8.3 Traffic Circulation ........................................................................................... 17

8.4 Community Facilities and Services ................................................................ 18

8.5 Public Utilities and Services........................................................................... 18

9.0 Environmental Resources ....................................................................................... 19

9.1 Noise ............................................................................................................. 19

9.2 Air Quality ...................................................................................................... 19

9.3 Visual Resources ........................................................................................... 19

9.4 Water Resources ........................................................................................... 19

9.5 Biological Resources ..................................................................................... 19

9.6 Cultural Resources ........................................................................................ 21

9.7 Soil Resources .............................................................................................. 22

9.8 Waste and Hazardous Materials Management .............................................. 23


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Photographs Photograph 1: Solar Panels in an Array .................................................................................. 5

Tables Table 1: Surrounding Land Use .................................................................................. 16

Figures Figure 1: Plot Plan and Surrounding Land Uses Figure 2: Solar Radiation and Project Location Figure 3: Electrical Collection System and Substation One-Line Diagram Figure 4: Screening Berm and Landscape Plan Figure 5: Site Infrastructure Figure 6: Project Phases Figure 7: Residences Located North of the Project Site

Exhibits (separate volumes) Exhibit A: Detailed Site Plan, Sections, and Elevations Exhibit B: Emergency Response Plan Exhibit C: Traffic Impact Analysis Exhibit D: Biological Site Assessment Exhibit E: Cultural Resource Study Exhibit F: Spill Prevention, Control and Countermeasure Plan Exhibit G: Waste Management Plan Exhibit H: Drainage Report


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1.0 Project Name and Location 1.1 Project Name Mesquite Solar Energy Project, herein referred to as the “project” or “facility” in this Narrative Report.

1.2 Location Figure 1 shows the location and boundaries of the project site. The project site comprises approximately 3,800 acres located immediately south of Elliot Road (the 2,520-acre original site located immediately east of the 411th Avenue alignment plus an 1,280-acre expansion area located immediately west of the 411th Avenue alignment), southwest of Wintersburg, Maricopa County, Arizona, approximately two miles west of the Mesquite Generating Station. The site includes Section 19 and portions of Sections 18 and 20 of Township 1 South, Range 6 West, and Sections 13, 14, and 15 and a portion of Section 24 of Township 1 South, Range 7 West, Gila and Salt River base and meridian.

The site has been partially developed with the Mesquite Solar 1 facility and supporting civil and electrical infrastructure, and it is otherwise currently vacant with the exceptions of (a) five groundwater wells and an associated pipeline on the original site that supply water to the Mesquite Generating Station and (b) El Paso Natural Gas pipelines that cross the southwest corner of the expansion area. The Palo Verde Nuclear Generating Station, Arlington Valley Energy Facility, and Mesquite Generating Station are located within two miles of the project site.


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2.0 Purpose of Request 2.1 Expansion of the Project Site This request for an amendment of the Special Use Permit (SUP) is to add the 1,280-acre expansion area to the project site, which will allow the more extensive development of a photovoltaic (PV) solar energy generation facility. As on the 2,520-acre original site, the facility in the expansion area will employ PV panels that absorb sunlight and directly produce electricity without use of heat transfer fluid or cooling water. The applicant and owner of the expansion area is SEP II, LLC (herein referred to as the “applicant”), an affiliate of Sempra U.S. Gas & Power. The facility will operate year-round, producing electric power whenever the sun is shining. When fully developed on both the original site and expansion area, the facility will produce up to 700 megawatts (MW) of clean solar power, which would supply the energy needs of up to about 260,000 residences. Energy from the facility is and will be sold to utilities in the wholesale market. The facility is planned to be developed at rate of 50 to 120 MW per year. The existing initial phase of the facility, known as Mesquite Solar 1, is located on the original site. Mesquite Solar 1 produces up to 165 MW and was completed in December 2012.

2.2 Project Benefits The economics of PV solar energy have improved dramatically over the past several years, making solar energy an electricity source of choice. Solar energy offers the opportunity to protect the environment by avoiding the production of greenhouse gases and other air emissions, decreasing our dependence on fossil fuels, and reducing the need for construction of fossil fueled power plants. Solar energy also benefits the economy generating jobs, business income, and tax revenue for Maricopa County and Arizona. Because solar energy is produced when demand for electricity is at its highest (during bright daylight hours), it helps to meet peak demand.

2.3 Site Suitability Key to solar energy production is the availability and intensity of solar radiation. Arizona is particularly well suited for solar energy, with more than 300 days per year of sunshine and relatively intense solar radiation. As shown in Figure 2, the general area of the project is highly suitable for solar energy production because it has some of the highest solar radiation levels in the United States. Other important criteria for determining the location of a solar energy generation facility include proximity to transmission facilities suitable for interconnection, land availability, flat terrain, and compatible adjacent land uses. As described herein, both the original site and the expansion area have all of these characteristics.


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3.0 Previous Approvals 3.1 CPA 200005 and SUP Z2000071 (Water Property) Of the 2,520 acres comprising the original site, 1,943 acres were part of approximately 3,000 acres acquired in 2001 for their groundwater rights needed to support operation of the Mesquite Generating Station. Land management of this “water property” was originally subject to SUP Z2000071 but has been transferred to CPA 200005. The transfer was made pursuant to an SUP amendment (referenced as SUP Z2013049) and an associated CPA (referenced as CPA 2013004).

3.2 CPA 200807 and SUP Z2008066 (Original Site) Of the 2,520 acres comprising the original site, 577 acres were acquired in 2007-08 that are additional to the 1,943 acres of water property. In December 2008, the Maricopa County Board of Supervisors approved (a) Comprehensive Plan Amendment (CPA) 200807, which designated the planned land use of the original site as Industrial for solar energy generation facilities, and (b) SUP Z2008066, which amended SUP Z2000071 by providing relief from the requirement to re-vegetate the water property to the extent that solar energy generation facilities are developed. The stipulation providing for such relief has been transferred to CPA 200005 pursuant to an SUP amendment (referenced as SUP Z2013049) and an associated CPA (referenced as CPA 2013004), and reads as follows:

If an SUP for any given portion of the water property is approved for use of that portion for solar energy generation facilities, then upon start of construction of such solar energy generation facilities, compliance with the Land Management Plan shall not require any past, existing, or future re-vegetation of that portion except as provided under said SUP, and instead the following land management conditions shall take effect:

1. All re-vegetated areas within the given portion of the water property are permitted to undergo vegetation removal as necessary for construction and operation of the solar energy generation facilities.

2. Measures to protect Centennial Wash shall be implemented as provided in the approved SUP for the solar energy generation facilities. These measures shall include soil stabilization and drainage control features.

3. Measures to control noxious weeds shall be implemented as provided in the approved SUP for the solar energy generation facilities.

4. Measures to control blowing dust and wind erosion shall be implemented as provided in the approved SUP for the solar energy generation facilities.

3.3 SUP Z2009022 and Amendments (Original Site) In January 2010, the Maricopa County Board of Supervisors approved SUP Z2009022, which provided for the development of solar energy generation facilities on the 2,520-acre original site. In February 2011, minor amendment Z2010073 was approved, reflecting a revised


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drainage design. In September 2012, minor amendment Z2012052 was approved, reflecting addition of an administration building.

3.4 CPA 200910 (Expansion Area) In December 2009, the Maricopa County Board of Supervisors approved CPA 200910, which designated the planned land use of the expansion area as Industrial for solar energy generation facilities.

3.5 Other Previous Approvals The subject project of this SUP application is limited to the solar energy generation facility. Other facilities associated with the project were the subject of other previous approvals.

An existing generation-tie power line that serves both the original site and the expansion area is under the permitting jurisdiction of the Arizona Corporation Commission. The power line operates at 230 kilovolts (kV) and is approximately four miles long. The power line consists of two circuits supported on a single set of tubular steel poles and extends from the 230 kV bus of the existing substation located on the original site to the existing 230 kV switchyard located at the Mesquite Generating Station. The power line route is shown on Figure 1. The Arizona Corporation Commission approved the power line in October 2009, and in November 2011 the power line began operation in conjunction with initial power generation by Mesquite Solar 1.

To accommodate interconnection of the power line, the Mesquite Generating Station 230 kV switchyard was modified to add new switching devices and termination structures. This modification, which was confined to the existing switchyard area and its immediate surroundings, was addressed in a minor amendment of SUP Z2000071 governing the Mesquite Generating Station. The minor amendment also addressed the portion of the new power line that is located on the site of the Mesquite Generating Station.


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4.0 Facility Description 4.1 Overview The solar energy generation facility employs PV panels that absorb sunlight and directly produce electricity. The facility consists of (a) a solar field of PV panels mounted on steel structures, (b) an electrical collection system that aggregates the output from the PV panels and converts the electricity from direct current (DC) to alternating current (AC), (c) a substation where all of the facility output is combined and transformed to a voltage of 230 kV, (d) civil infrastructure including driveways, drainage channels, a screening berm, and fencing, and (e) an administration building. The substation and administration building are located on the original site and will also serve the expansion area.

Figure 1 provides a plot plan of the site in the context of surrounding land uses, and Exhibit A provides a detailed site plan, sections, and elevation drawings. Photograph 1 shows PV panels at the Mesquite Solar 1 facility. The PV panels that will be installed on the balance of the original site and in the expansion area will be similar in general appearance to the panels shown in the photograph.

Photograph 1: Solar Panels in an Array (Photograph from Mesquite Solar 1)

4.2 Solar Field As on the original site, the solar field in the expansion area will consist of PV panels mounted on steel support structures. The supports will be either fixed or pivoting, depending on the specific PV panel manufacturer(s) selected. In either case, the assembled PV panels will have a typical height of about 6 feet and a maximum height of 8 feet. The PV panels will be arranged in rows with center-to-center


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spacing of 12 to 22 feet. In the case of fixed supports, the rows will be aligned east to west and the PV panels will be tilted to the south. In the case of pivoting supports, the rows will be aligned north to south and the PV panels will pivot, tracking the sun, east to west.

4.3 Electrical Collection System As on the original site, the PV panels in the expansion area will be organized into electrical groups referred to as “blocks.” Each block will encompass a minimum 6 acres of PV panels (producing at least 1 MW) and will include one modular inverter enclosure. The size of each block will depend upon the capacity of the inverters housed in the block’s associated inverter enclosure, which in turn will depend upon the type and size of inverters available for purchase and other such electrical design considerations.

Conductors, hung under the PV panels and extending underground, will feed the DC to AC inverters and associated switchgear housed in each block’s inverter enclosure. Each inverter enclosure is anticipated to be a 12-foot-by-34-foot pre-fabricated structure up to 15 feet in height and will be unoccupied except during inspection and maintenance. Each inverter enclosure will have an associated outdoor transformer to step up the electricity voltage from the inverter output level (e.g., 480 V to 34.5 kV). From each such transformer, electricity will be conveyed via an underground circuit to 34.5 kV switchgear housed in a modular collection enclosure that gathers the output of up to 30 MW of PV panels. Each collection enclosure is anticipated to be an 8-foot-by-60-foot pre-fabricated structure up to 12 feet in height and cannot be occupied.

From each collection enclosure, electricity will be conveyed via an underground 34.5 kV collector circuit to a common 34.5 kV bus within the existing substation located on the original site. Such underground collector circuits originating in the expansion area will cross the 411th Avenue alignment near the north and/or south boundaries of the expansion area.

4.4 Substation Figure 3 shows a conceptual one-line diagram of the electrical collection system and substation. The substation is a central hub for the 34.5 kV collector circuits and step ups the electricity voltage from 34.5 kV to 230 kV. The substation site is approximately 6 acres in size and includes, but is not limited to, the following major components:

• 34.5 kV bus and associated switching devices • 230 kV bus and associated switching devices • 187 MVA, 34.5/230 kV transformers • 34.5 kV capacitors • Tubular steel support structures up to 40 feet in height • Grounding grid • Prefabricated modular control building (unoccupied except during inspection and maintenance) • Perimeter fence


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4.5 Driveways As shown on Figure 1 and Exhibit A, driveways on the site consist of a main access driveway, a perimeter driveway, and a series of internal driveways. Driveways east of the 411th Avenue alignment are on the original site, and driveways west of the 411th alignment are in the expansion area. The original site has two access points from Elliot Road, and the expansion area will add a third access point from Elliot Road. The main access driveway to the project site extends from Elliot Road along the 399th Avenue alignment to the southern edge of the original site. This existing driveway provides access to the Mesquite Solar 1 facility, the substation, the administration building, the five water wells and pipeline serving the Mesquite Generating Station, and a distribution power line serving the well pumps. The main access driveway is 24 feet wide and is paved from Elliot Road to the substation and administration building; this is the only pavement anywhere on the project site other than parking areas. The remainder of the main access driveway is of unpaved engineered construction.

The second access point is an existing secondary access at the 411th Avenue alignment (northwest corner of the original site), and the third access point will be a secondary access at the 427th Avenue alignment (northwest corner of the expansion area); these driveways are 24 feet wide and of unpaved engineered construction. The perimeter driveway, which will be expanded to surround the entirety of both the original site and expansion area, is also 24 feet wide and of unpaved engineered construction. Four lateral driveways running east-west across the interior of the original site, perpendicular to the main access driveway, provide access into the solar field for maintenance. Similarly, two more lateral driveways will run east-west across the interior of the expansion area. The lateral driveways are 12 feet wide and of unpaved engineered construction.

As used herein, the phrase “unpaved engineered construction” refers to an unpaved driveway surfaced with gravel and/or millings and having a design based on engineering considerations including native soil characteristics, traffic frequency and weight, drainage, and dust control.

4.6 Drainage Design The original site and much of the expansion area was historically used for flood-irrigated agriculture, so the project site is generally planar and dips slightly to the southeast at an approximately constant slope of 0.6 percent. Off-site storm water flows approach the project site from the northwest and these flows, along with the flows that are generated on-site, flow to Centennial Wash to the south and southeast of the site. To the extent practical, the project’s drainage design preserves the existing locations and characteristics of flows entering and exiting the site. The project Drainage Report is provided as Exhibit H.

As shown on Figure 1 and Exhibit A, a system of drainage channels mitigates the effects of storm water flows on the facility. Perimeter channels along the north, east, and west boundaries of the original site divert off-site flows around the site and ultimately into the Centennial Wash floodplain. Similarly, a perimeter channel along the north boundary of the expansion area will divert off-site flows around the site and into the west perimeter channel of the original site. A drainage berm along the west boundary of the expansion area will ensure that off-site flows to the west, which already flow nearly due south, do not enter the project site. Four interior channels (running east-west along each


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lateral driveway) intercept flows generated on the original site and divert these flows to a perimeter channel to prevent flows from accumulating across the entire site. Similarly, two more interior channels will intercept flows generated in the expansion area and divert these flows to a perimeter channel. The resulting reduction in runoff depths and velocities, together with the more uniform site contours that will result from grading the areas between the interior channels, will promote sheet flows, diminish concentrating flows, and lessen the occurrence of localized ponding and soil saturation. The interior channels also function as retention basins to the extent necessary to meet drainage design criteria. The perimeter and interior channels will be sized for 100-year peak runoff flows, and the retention volume will be sized to ensure that there is no increase in the 100-year runoff flows exiting the site.

A very small percentage of the site is covered with impervious surface (i.e., the paved portion of the main access driveway and the modular enclosures). The rows of PV panels canopy narrow strips of the site, and the ground surface under the PV panels and between the rows remains open. On-site runoff has full access to the ground surface for infiltration.

The PV panels do not introduce pollutants to storm water. Transformers which may contain insulating mineral oil, gasoline and diesel fuel tanks serving site vehicles and an emergency generator, and a drum for waste lubricating oil are the only facility equipment that could present the potential for introducing pollutants to storm water. To eliminate such potential, each transformer, fuel tank, and drum installation includes secondary containment consisting of a concrete or metal basin having sufficient volume for 100 percent of its liquid contents plus retention of the 24-hour volume from a 100-year storm event.

4.7 Grading Design As shown on Exhibit A, grading between the lateral channels generally follows the existing topography except in a southerly area of the original site that is located within the designated flood fringe of the Centennial Wash floodplain. To raise the existing topography above flood levels, grading in this southerly area will include the placement of clean earthen fill. These grading activities will not involve dredging or filling Centennial Wash and will not trigger U.S. Army Corps of Engineers (USACE) permitting requirements. Grading also includes constructing a screening berm along Elliot Road, filling relatively small existing basins previously used for agricultural purposes, and removing abandoned houses, remnants of concrete irrigation ditches, and other such structures. The intent of the project’s grading design is to minimize the amount of earthwork performed.

4.8 Screening Berm and Landscaping As shown on Figure 1 and Exhibit A, the project includes a screening berm along Elliot Road, on the site side of the perimeter drainage channel. Figure 4 provides a cross section of the berm and shows sight lines and landscaping details. The existing berm at the north edge of the original site extends for approximately 1.5 miles along Elliot Road, from the 399th Avenue alignment to the 411th Avenue alignment. The berm will be extended further west at the north edge of the expansion area for approximately 0.5 mile along Elliot Road, from the 411th Avenue alignment to the 415th Avenue alignment. The berm height varies between 6 and 8 feet.


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The purpose of the screening berm and associated landscaping is to provide an aesthetically pleasing buffer between (a) the solar energy generation facility and (b) Elliot Road and the residences located north of Elliot Road. The top and northern side of the berm, facing Elliot Road, includes native and drought-tolerant trees, shrubs, and ground cover to enhance the screening and add visual interest. These plants include strong native trees and evergreen shrubs with seasonal accent flowers to provide color. The intent of the design is to imitate the native desert with organic and natural groupings. The landscaping will be irrigated with a drip system until the plants are established, which is expected to require three to five years. Once the plants are established, the irrigation will be gradually reduced until it is used only for occasional watering during extreme drought conditions. The southern side of the berm, facing the project site interior, includes stabilization with a native seed mix and/or soil stabilizer.

4.9 Fencing As shown on Exhibit A, the perimeter of the original site is enclosed by a 6-foot-high chain link fence topped with a one-foot barbed wire section, and the expansion area will be similarly enclosed. The fence posts are at 10-foot intervals. The two access points from Elliot Road to the original site are gated and have swinging or rolling chain link gates, and the third access point to the expansion are will be similarly gated. So that off-site storm water flows may enter the perimeter channels without hindrance, and to provide an open presentation of the screening berm and associated landscaping as viewed from Elliot Road, the fence is located on the site side of the berm. The fence is designed to prevent wildlife from entering the site for the reasons explained in Section 9.5, Biological Resources.

4.10 Administration Building The administration building was added to the SUP by minor amendment Z2012052 approved in September 2012. Major elements of the administration building include the following:

• Office space for plant operators and administration personnel • Control room • Shop • Warehouse • Parking • Auxiliary systems (electrical, water supply, fire protection, and sanitary waste system)

As shown on Figure 1 and Exhibit A, the administration building is located south of the substation. Exhibit A provides a detailed site plan, sections, and elevation drawings for the administration building. The paved driveway to the substation has been extended to provide access to the administration building. Parking facilities are provided for permanent plant personnel and visitors as shown on Exhibit A.

An exempt domestic well (i.e., not associated with groundwater rights) provides water to the administration building. Where necessary, small, cartridge type reverse osmosis systems (using disposable cartridges) are installed at local fixtures. Reverse osmosis system reject water is drained to the sanitary waste system. The sanitary waste system includes a septic tank and leach field.


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To support operation and maintenance of site vehicles and an emergency generator, the administration building area will include a 120 gallon gasoline tank, a 240 gallon diesel fuel tank, and a 55 gallon drum for waste lubricating oil. Each fuel tank and drum installation includes full secondary containment as described in Section 4.6, Drainage Design. Waste lubricating oil will be periodically collected by a qualified waste hauler for recycling.

The administration building is provided with fire protection systems as described in Section 7.2, Fire Protection, including a 40,000 gallon fire water storage tank.


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5.0 Construction 5.1 Project Phases and Schedule Construction already completed in conjunction with Mesquite Solar 1 consists of civil and electrical infrastructure on the original site including (a) perimeter drainage channels, (b) three interior channels for on-site storm water flows incorporating the retention volume necessary for Mesquite Solar 1, (c) main access driveway, perimeter driveway, and three lateral driveways, (d) screening berm along Elliot Road and associated landscaping, (e) fencing, (f) the substation, and (g) the administration building. This existing site infrastructure is shown on Figure 5, except for fencing which is shown on Exhibit A.

As shown on Figure 6, construction of the solar energy generation facility will occur in seven phases, with Mesquite Solar 1 constituting the first phase. Subsequent phases will proceed first on the remainder of the original site from north to south, and then in the expansion area from north to south. If a partial phase is constructed, construction will proceed from east to west across the phase area. If more than one phase is constructed simultaneously, completion of such simultaneous work will result in contiguous development of the project site without intervening undeveloped areas. The perimeter drainage channel, drainage berm, and screening berm in the expansion area will be constructed prior to or concurrently with construction of the first phase in the expansion area.

During the construction of each phase, equipment will be placed in service at the completion of each block of PV panels. This in-service timing is critical because PV panels become energized as soon as they are exposed to sunlight, and a delay in power flow would waste valuable energy production and may cause the need for extraordinary construction measures to avoid damage to the PV panels.

Construction of the site infrastructure shown on Figure 6 began in April 2011 and was completed in late 2011. Construction of Mesquite Solar 1 was conducted concurrently with construction of the site infrastructure and was completed in December 2012. Construction of subsequent phases is planned to take place over four to eight years and will depend upon market conditions and PV panel manufacturing rates.

5.2 Construction Workforce and Workspace Construction of the facility is expected to require a peak workforce of approximately 500 management, supervisory, and craft workers. Parking, temporary office trailers, a temporary warehouse, and equipment laydown areas will be located within or immediately adjacent to each respective phase area during construction of that phase. The warehouse may be up to 40 feet in height and will be removed upon construction completion and contractor demobilization of the phase served by the warehouse.

5.3 Site Preparation and Grading Activities The project site is generally bare land and was historically used for agriculture. Existing vegetation includes sparse desert grasses, shrubbery, and some scattered desert trees. Most of the vegetation on the original site exists in narrow strips with intervening broad areas of bare ground as a consequence of drip-irrigated re-vegetation efforts. Vegetation has been removed from the areas


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where site infrastructure and Mesquite Solar 1 are located and will be removed from the areas where additional PV panels will be placed. No vegetation is permissible among the PV panels in order to avoid shading and brush fire hazard. However, vegetation will remain in place in each phase area until start of grading on that area. Site preparation will include removal of abandoned houses, remnants of concrete irrigation ditches, and other such structures.

Grading for the site infrastructure described in Section 5.1, Project Phases and Schedule, focused on the perimeter of the original site. Concurrently, interior areas of the original site were graded for Mesquite Solar 1. Otherwise, no substantial grading or other work was performed in the interior of the site except constructing the main access driveway, filling two relatively small existing basins previously used for agricultural purposes, and conducting activities associated with construction of the site infrastructure. To provide for balanced cut-and-fill quantities, such activities included placement and compaction of excess materials in low elevation areas of the site interior.

Construction of each future phase will include (a) grading of the phase area and (b) construction of the interior channel and lateral driveway located immediately south of the phase area. The interior channel will incorporate the storm water retention volume necessary for the phase.

Gravel and/or millings will be imported to the site for construction of the driveways. For a 6-inch road section, approximately 64,000 cubic yards of material are required for construction of all driveways on the entire project site. Of this total, approximately 36,000 cubic yards are required for the original site (of which approximately 23,000 cubic yards are associated with construction already completed) and approximately 28,000 cubic yards are required for the expansion area. Water will be used during grading to control dust and to achieve proper moisture content in the soil being graded. The water will be provided from the existing wells located on-site.

5.4 Equipment Installation Construction of each phase will include (a) installation of the electrical collection system for that phase, (b) installation of PV panel supports, and (c) installation of PV panels.


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6.0 Operation 6.1 Operation Workforce Operation of the facility is managed, monitored, and controlled by on-site staff. The facility currently has twelve full-time employees. When fully developed, operation and maintenance of the facility is expected to require twelve additional full-time employees (six additional employees for the original site plus six more additional employees for the expansion area).

6.2 Facility Maintenance PV facilities contain virtually no moving parts and have limited maintenance requirements. Maintenance activities consist of checking electrical performance parameters that are not transmitted to the administration building for remote monitoring, performing periodic inspections and maintenance of transformers and inverters, responding to any problems detected by remote monitoring, conducting weed abatement and dust control activities, cleaning PV panels, and maintaining driveways. Water is used for cleaning PV panels and controlling dust, but no water is used by the facility for the production of electricity. No major equipment is anticipated to be required for maintenance of the facility except as necessary for periodic re-grading of driveways.

6.3 Site Security Site security is provided by cameras monitored at the administration building and by periodically driving along the site perimeter security fence. The cameras are mounted on poles with a maximum height of 20 feet. As shown on Exhibit A, the pole locations are generally at half mile intervals along the site perimeter. Additional pole locations along the perimeter and in the site interior are near facilities of particular security interest.

6.4 Weed Management and Dust Control Installation of the site infrastructure and Mesquite Solar 1 has resulted in the complete removal of vegetation from the areas of those installations. Build-out of the solar energy generation facility will likewise result in the complete removal of vegetation. Areas where PV panels, other electrical equipment, and site infrastructure are placed are maintained free of vegetation through use of herbicides.

Dust control is critical to the successful operation of a solar energy generation facility because dust diminishes the power output of PV panels, increases their cleaning requirements, and reduces the reliability of electrical equipment. The primary measures to control dust are (a) establishing and maintaining a crust on the soil surface using water and possibly dust palliative, (b) avoiding disturbance of the established crust by either vehicles or foot traffic, (c) limiting the speed of maintenance vehicles, and (d) using water during periodic re-grading of driveways. The specifics of effective dust control parameters (e.g., type and quantity of dust palliative, if used, appropriate maximum vehicle speed, etc.) are determined by empirical testing performed on-site.


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7.0 Health and Safety 7.1 Health and Safety Program Safety issues are primarily related to project construction and relate to the following potential hazards:

• The movement of construction vehicles, equipment, and materials • Falls into open excavations • Electrocution • Heat-related illnesses • Poisonous snakes and insects

These issues are particularly relevant to construction personnel who work in close proximity to construction vehicles, equipment, and materials and who are potentially exposed to such hazards on a daily basis. Risk of construction-related injury is minimized through careful safety planning, regular safety training, and use of appropriate safety equipment.

Operation of a solar PV facility is safer than other forms of energy production, because the electricity generation process does not involve combustible fuel, high temperature, or high pressure. In addition, the only potentially toxic or hazardous material that will be present on-site is the mineral oil contained in the transformers, and each transformer will be provided with full secondary containment. The hazards inherent in operation and maintenance work with energized (or potentially energized) equipment are addressed through a combination of training, procedures (such as lock-out-tag-out protocols), and personal protective equipment (gloves, apparel, eyewear, etc.).

7.2 Fire Protection No permanent fire protection system is included for the solar field, because PV panels and their support structures are constructed of glass, aluminum, and steel, none of which are subject to combustion. All oil-filled transformers are located outdoors with proper setback from adjacent structures. Areas where PV panels, other electrical equipment, and site infrastructure are placed are maintained free of vegetation. The three site access driveways serve for emergency egress and fire department access.

The administration building is provided with the following fire protection systems:

• Fire water storage tank (40,000 gallons) with a diameter of 27 feet and a height of 18.5 feet. • Electric motor driven fire water pump with two sources of electricity (an Arizona Public Service

distribution circuit and the Salt River Project grid via the project’s interconnection facilities). • Piping systems and appurtenances for sprinkler systems. • FM-200 fire protection system for the control room and SCADA (system control and data

acquisition) room.


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7.3 Emergency Management Plans Operation of the facility is managed by the on-site staff. The staff is trained for emergency management and response under the Emergency Response Plan that has been prepared for the Mesquite Solar project and is provided as Exhibit B.

The project site is located within the 10-mile Plume Exposure Pathway Emergency Planning Zone (EPZ) for the Palo Verde Nuclear Generating Station (PVNGS). The EPZ has been established to address the potential for radioactive contamination in the event of a major emergency at PVNGS. To address the time required for evacuation of the construction workforce in the event of such an emergency, the applicant will meet with representatives of PVNGS, the Maricopa County Department of Transportation (MCDOT), and the Maricopa County Sheriff’s Office to discuss on-site circulation and off-site traffic impacts. In the event of such an emergency, the operation staff of the Mesquite Solar project will implement the applicable evacuation plan specified in the facility’s Safety Plan.


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8.0 Land Use and Community Resources 8.1 Land Use on the Project Site and Surroundings The project site consists of former farmland and desert, much of which is in the process of being revegetated with desert flora pursuant to the Land Management Plan administered by Maricopa County under CPA 200005 (further amended as CPA 2013004). The site has been partially developed with the Mesquite Solar 1 facility and supporting civil and electrical infrastructure, and it is otherwise currently vacant with the exceptions of (a) five groundwater wells and an associated pipeline on the original site that supply water to the Mesquite Generating Station and (b) El Paso Natural Gas pipelines that cross the southwest corner of the expansion area. As described in Section 3.0, Previous Approvals, the planned land use for both the original site (under CPA 200807) and the expansion area (under CPA 200910) is Industrial for solar energy generation facilities.

Existing land uses surrounding the project site consist of vacant desert/grazing land to the west, south, and east; several rural single-family residences and a 400-acre open space area to the north across Elliot Road; an 80-acre wildlife area to the immediate northeast; and a 320-acre wildlife area to the immediate southeast. The open space area and both wildlife areas are maintained by the applicant pursuant to the Land Management Plan administered under CPA 200005 (further amended as CPA 2013004). Centennial Wash runs adjacent to the southwestern corner of the original site. Three major power generation facilities (designated Industrial land use) are located within two miles of the project site, including the Palo Verde Nuclear Generating Station, Arlington Valley Energy Facility, and Mesquite Generating Station.

Figure 1 shows existing land uses adjacent to the project site. Figure 7 shows and provides identifying information for the individual residential parcels located to the north, across Elliot Road. Table 1 summarizes the surrounding land uses and Comprehensive Plan land use designations.

Table 1: Surrounding Land Use

Property Location Existing Use Comprehensive Plan Designation

Original Site Solar Energy Generation Facility and Vacant Industrial for solar energy generation facilities

Expansion Area Vacant Industrial for solar energy generation facilities

West Vacant/Grazing Rural Densities

Southwest Vacant/Grazing Dedicated Open Space, Other Open Space, and Rural Densities

Southeast Wildlife Habitat Dedicated Open Space

East Vacant/Grazing State Land

Northeast Wildlife Habitat Dedicated Open Space

North Rural Single-Family Residential and Vacant Rural Densities and Dedicated Open Space


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8.2 Site Access and County Right-of-Way Access to the project site is provided off Elliot Road via Wintersburg Road. Elliot Road is a two-lane paved roadway. Primary access off Elliot Road is paved and is located along the western edge of the 80-acre wildlife habitat area (399th Avenue alignment). A secondary access off Elliot Road is located at the northwestern corner of the original site (411th Avenue alignment). An additional secondary access off Elliot Road will be located at the northwestern corner of the expansion area (427th Avenue alignment). At both the 411th Avenue and 427th Avenue secondary access points, pavement will be extended from the edge of the Elliot Road pavement to the south edge of the County right-of-way.

The Elliot Road frontage along the original site has been dedicated to Maricopa County pursuant to SUP Z2009022, and the Elliot Road frontage along the expansion area has been preserved for future dedication to Maricopa County pursuant to CPA 200910, in each case extending 100 feet south from the Section line. The 411th Avenue alignment along the original site has been dedicated to Maricopa County pursuant to SUP Z2009022, and the 411th Avenue alignment along the expansion area has been preserved for future dedication to Maricopa County pursuant to CPA 200910, in each case extending 65 feet west or east from the Section line. The 395th Avenue alignment along and through the original site has been dedicated to Maricopa County pursuant to SUP Z2009022, extending 65 feet west and east from the Section line.

The applicant requests that any Maricopa County right-of-way existent along the 419th Avenue alignment be vacated. To provide the access that any such right-of-way would otherwise have provided, applicant proposes to establish a private access easement on the Narramore Road alignment (at the south edge of the expansion area), from the 411th Avenue alignment to the 419th Avenue alignment, extending 50 feet north from the Section line.

Certain project facilities will cross Maricopa County right-of-way at the 411th Avenue alignment, including (a) underground 34.5 kV collector circuits crossing near the north and/or south boundaries of the expansion area as described in Section 4.3, Electrical Collection System, (b) perimeter driveways crossing near the north and south boundaries of the expansion area as described in Section 4.5, Driveways, and (c) a perimeter channel along the north boundary of the expansion area and two interior channels extending from the expansion area as described in Section 4.6, Drainage Design. In addition, certain other project facilities will cross Maricopa County right-of-way at the 395th Avenue alignment near the southeast corner of the original site, including (d) a perimeter driveway, (e) a perimeter channel, and (f) a perimeter channel outlet weir. In each case, the appropriate approval will be obtained from MCDOT prior to construction.

8.3 Traffic Circulation A Traffic Impact Analysis is provided as Exhibit C. The 2012 average daily traffic (ADT) on Wintersburg Road (383rd Avenue) at Elliot Road, about 1.5 miles east of the project site, is 724 vehicles per day. The analysis concluded that construction and operation of the project will result in negligible impacts on the existing roadway system.

Construction of the facility is estimated to require materials deliveries that will add approximately 10 to 12 semi trucks per day to Elliot Road. Heavy trucks will not be allowed to use Elliot Road west of a


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point that is 200 feet west of the 411th Avenue alignment. Construction is expected to require a peak construction workforce of approximately 500 workers. Parking will be provided on-site for personal vehicles, and it is estimated that the construction workforce will add up to 1000 vehicles per day to Elliot Road. Minimal traffic will be generated by the mobilization and demobilization of equipment used for earthwork including scrapers, graders, water wagons, and compactors. Likewise, minimal traffic will be generated by the mobilization and demobilization of other equipment used in constructing the facility, including truck-mounted post drivers, skid loaders, forklifts, etc.

Operation of the facility is estimated to add up to 150 vehicles per day to Elliot Road. It is expected that the majority of trips will consist of employee and equipment maintenance trips.

8.4 Community Facilities and Services Construction of the facility is expected to require a peak workforce of approximately 500 workers. As this workforce is expected to draw upon the existing labor pool in western Maricopa County, construction will not significantly affect area facilities and services.

Operation of the facility is managed, monitored, and controlled by on-site staff. The facility currently has twelve full-time employees. When fully developed, operation and maintenance of the facility is expected to require twelve additional full-time employees (six additional employees for the original site plus six more additional employees for the expansion area), which will not affect community facilities and services.

8.5 Public Utilities and Services No utility extensions are planned for the project, and no new or additional public services are anticipated as a result of the project.

Electric and telecommunication utilities are present in the project vicinity to support scattered rural residences. Domestic water in the project vicinity is supplied via private wells. Groundwater in the project vicinity does not meet National Secondary Drinking Water Regulations (NSDWRs) due to its high Total Dissolved Solids (1,600 to 1,700 mg/liter versus the NSDWR of 500 mg/liter), and its status with respect to National Primary Drinking Water Regulations is unknown to the applicant. No sewer services exist in the project vicinity, and sanitary waste is managed by the use of private septic systems.

The project site is served by an Arizona Public Service electric distribution circuit providing power to the groundwater well pumps, the administration building, and substation auxiliary loads. Century Link provides telecommunication service to the administration building. As there is no public water system in the project vicinity, bottled drinking water is transported to the site. An exempt domestic well (i.e., not associated with groundwater rights) serves the administration building, supplying water for uses such as the sanitary waste system. The sanitary waste system includes a septic tank and leach field.

The Maricopa County Sheriff’s Office provides police protection to the area. The project site is located within the District II patrol area, and the nearest substation is located at 920 E. Van Buren Avenue in Avondale. The Buckeye Valley Fire District provides fire protection and emergency response services to the area.


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9.0 Environmental Resources 9.1 Noise The source of noise discernible off site during construction will primarily be the heavy equipment used during earthwork for the drainage channels and screening berm along Elliot Road. There is no discernible noise off site during operation of the facility.

9.2 Air Quality The project does not and will not produce discernible levels of any odors. Dust will be controlled during construction as described in Section 5.3, Site Preparation and Grading Activities, and during operation as described in Section 6.4, Weed Management and Dust Control.

9.3 Visual Resources The visual impacts of a PV solar energy generation facility are relatively small because of its low profile and because PV panels absorb light and do not cause glare. To further mitigate visual impacts, the project includes construction of a context-sensitive, landscaped berm along Elliot Road as shown on Figure 1 and Figure 4. The existing berm screens the facility on the original site and provides an attractive amenity along Elliot Road. To yield the same result for the expansion area, the berm will be extended further west to the 415th Avenue alignment, west of which only BLM land exists on the north side of Elliot Road.

The project area does not provide recreational opportunities and does not generate an abundance of public attention. While the closest residence to the project site is less than 0.10 mile away to the north, across Elliot Road, the facility is not visible from that vantage point due to the landscaped screening berm along Elliot Road.

9.4 Water Resources Water will be used during construction as described in Section 5.3, Site Preparation and Grading Activities, and during operation as described in Section 6.2, Facility Maintenance, and Section 6.4, Weed Management and Dust Control. All water except drinking water will be provided from the existing wells located on-site. Five wells are associated with the applicant’s groundwater rights, totaling about 8,000 acre-feet/year, of which 7,500 acre-feet/year is typically delivered to the Mesquite Generating Station and 500 acre-feet/year is allocated for use on the project site. It is expected that project construction will use less than 500 acre-feet/year, and that project operation will use less than 150 acre-feet/year. One additional well is an exempt domestic well (i.e., not associated with groundwater rights) that serves the administration building.

9.5 Biological Resources A biological assessment of the 2,520-acre original site was performed in 2008 to characterize environmental conditions and to identify and analyze special status species that would require additional surveys, additional permits, or mitigation under federal or Arizona State law. Similarly, a biological assessment of the 1,280-acre expansion area was performed in 2013. The Biological Site Assessments are provided as Exhibit D.


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A reconnaissance-level biological survey of the original site was performed in April 2008 by Steve Yarbrough, a senior biologist from EDAW AECOM. The sparse vegetation present was primarily creosote bush arranged in narrow, parallel strips with an expanse of bare ground between each strip, as the result of drip irrigation used in revegetation efforts. Hawks were the only wildlife observed during the reconnaissance. A significant amount of the reconnaissance was spent evaluating Centennial Wash, which is located adjacent to the original site. The discernible, vegetated portion of this desert wash is a major physiographic feature in an otherwise very flat, arid, Sonoran Desert landscape. The wash was lined with velvet mesquite and foothills paloverde trees. The wash was dry at the time of the reconnaissance, appeared likely to flow only in response to large precipitation events, and did not contain a prevalence of hydrophytic vegetation. No features observed in other parts of the original site or its immediate vicinity were indicative of wetlands or “waters of the U.S.” as defined by USACE.

A reconnaissance-level biological survey of the expansion area was performed in May 2013 by Ian Tackett and Peter Gosling, biologists from Logan Simpson Design, Inc. Similar to the original site, the vegetation present in the expansion area consisted primarily of low stature creosote bush that was sparse in some areas and fairly dense in other areas with an occasional understory of white bursage and scattered cacti. Cacti found in the expansion area included diamond cholla, buckhorn cholla, California barrel cacti, and strawberry hedgehog cacti. Saguaro cacti were also present, although at an extremely low density with only a few individuals observed. Wildlife observed in the expansion area included desert iguana, tiger whiptail lizard, desert horned lizard, coachwhip snake, Harris’s antelope ground squirrel, coyote, Gambel’s quail, turkey vulture, and Le Conte’s thrasher. An active Le Conte’s thrasher nest with three eggs was observed in the northeastern portion of the expansion area during the reconnaissance.

A protected species review of the original site was conducted in 2008 by consultation over the telephone and in writing with the U.S. Fish and Wildlife Service (USFWS), Arizona Department of Agriculture (AZDA), and Arizona Game and Fish Department (AZGFD), and a subsequent meeting was held with AZGFD. USFWS, the agency that has regulatory authority over federally listed threatened and endangered species, migratory birds, and bald and golden eagles, did not identify any plants or animals of concern or suggest surveys. AZDA indicated a notice of intent must be filed if straw-top cholla is to be impacted because this cactus is designated as a salvage-restricted species. AZGFD identified straw-top cholla, western burrowing owl, LeConte’s thrasher, and possibly kit fox and Sonoran desert tortoise as species of concern in the project vicinity. The four animal species are not protected by state or federal statute, and only the Sonoran desert tortoise is considered a species of concern by AZGFD. Additional review conducted at the request of AZGFD concluded that, based on the site characteristics and published studies, there is significant potential for the occurrence of western burrowing owl and lesser potential for the occurrence of LeConte’s thrasher on the original site. The review also concluded that kit fox, if found on the original site, would likely only be passing through the area because past farming has limited suitable breeding habitat. Similarly, the review concluded that there is very low probability of occurrence of Sonoran desert tortoise on the original site due to lack of suitable habitat. Accordingly, AZGFD recommended that surveys be performed for western burrowing owl and LeConte’s thrasher on the original site, and such surveys were performed prior to construction of the development already completed.


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A protected species review of the expansion area was conducted on-line with USFWS and AZGFD in June 2013. No federal or state listed threatened or endangered species were identified as occurring in the expansion area. The AZGFD On-line Environmental Review Tool indicated that two species, straw-top cholla and Sonoran desert tortoise, have been documented as occurring within five miles of the expansion area. However, due to the adjacency and biological similarities of the expansion area to the original site, Sonoran desert tortoise has low probability of occurring in the expansion area.

Based on AZGFD recommendations provided in a letter dated November 6, 2013, a combined survey for western burrowing owl, LeConte’s thrasher, kit fox, and Sonoran desert tortoise will be conducted prior to construction of each additional phase of development. The survey(s) will be performed by a certified biologist within 30 days of construction and in accordance with the requirements outlined in the Burrowing Owl Project Clearance Guidance (AZGFD January 2009) and the Desert Tortoise Survey Guidelines (AZGFD June 2010). If surveys identify breeding populations during the nesting season (March through mid-July for owl, February through June for thrasher), a buffer area will be staked and flagged, and heavy machinery activity and foot traffic within the buffer area will be avoided until the appropriate conservation action is determined and completed.

Because the developed project site will lack vegetation to sustain wildlife, AZGFD recommended that the project fencing be designed to prevent wildlife from entering the site. Such fencing will direct wildlife around the project site to Centennial Wash, which provides a wildlife habitat connectivity corridor. Centennial Wash will not be affected by construction of the project.

9.6 Cultural Resources A Class I cultural resources survey was performed in 2009 for the 2,520-acre original site, the generation-tie power line route, and a one-mile buffer around these lands. The one-mile buffer included the eastern half of the 1,280-acre expansion area. No archaeological sites had been previously recorded on the original site or on the eastern half of the expansion area. Fourteen archaeological sites had been recorded in the remaining buffer areas. Because of the presence of recorded archeological sites in the buffer areas, a Class III survey was recommended.

The Class III survey of both the original site and the expansion area was conducted in February 2010 by archaeologists from PaleoWest Archaeology. The survey recorded five new archaeological sites (three historic and two prehistoric) and also documented a recorded historic road segment. The information potential of four of the sites is considered to have been exhausted through data collection and documentation during the Class III fieldwork. Therefore, those sites were recommended as ineligible for listing on the National Register (pending SHPO concurrence), and no further treatment of these resources is warranted. The previously recorded historic road segment has already been determined to be not eligible by the SHPO.

The fifth site (AZ T:9:122 (ASM)) consisted of a prehistoric artifact scatter measuring approximately 117 meters by 50 meters located in the southwestern quadrant of the expansion area. Because this site may yield new or significant information on the local or regional prehistory of the area, it was recommended as eligible for the National Register under Criterion D, pending SHPO concurrence. As disturbance to the site cannot be avoided, if SHPO concurs that this resource is eligible for listing, then a cultural resource data recovery will be initiated.


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In accordance with Arizona state law, if human remains or burial goods are encountered during any ground disturbing activities, work in the immediate vicinity will cease and the Director of the Arizona State Museum will be notified.

9.7 Soil Resources As described in Section 5.1, Project Phases and Schedule, and Section 5.3, Site Preparation and Grading Activities, construction of the project requires that 3,800 acres of land be disturbed by clearing and grading in stages. Of that total, approximately 900 acres has been disturbed to date for construction of the site infrastructure described in Section 5.1, Project Phases and Schedule, and for construction of Mesquite Solar 1. A Storm Water Pollution Prevention Plan (SWPPP) has been prepared and implemented to address construction activities. Best management practices have been adapted to site conditions and employed to avoid soil erosion and off-site impacts during construction.

As described in Section 4.6, Drainage Design, a system of drainage channels manages off-site and on-site storm water flows such that the existing locations and characteristics of flows entering and exiting the site are preserved to the extent practical. On-site flows are segregated from off-site flows and conveyed to interior channels that function as retention basins sized to ensure that there is no increase in the 100-year runoff flows exiting the site. The project’s drainage design results in no adverse effects on Centennial Wash or other adjacent lands. The project Drainage Report is provided as Exhibit H.

Under existing conditions, on-site runoff is generally characterized by shallow and slow flows. Because of the site’s flat topography (approximately constant slope of 0.6 percent), runoff generally flows slower than scouring velocities of the soil (i.e., under 2.5 feet per second). However, previous modeling by Maricopa County indicates the potential for greater runoff depths than are generally evidenced by indications on the site. Were flows to concentrate in association with such greater depths, velocities might increase and exceed the scouring limits of the soils.

The primary erosion control features of the project are the system of drainage channels. Perimeter channels reduce on-site flows by preventing off-site flows from entering the interior of the site. Interior channels extending across the site at regular intervals intercept flows generated on-site and divert these flows to a perimeter channel, thereby preventing flows from accumulating across the entire site. The resulting reduction in runoff depths and velocities, together with the more uniform site contours resulting from grading the areas between the interior channels, promotes sheet flows, diminishes concentrating flows, and lessens the occurrence of localized ponding and soil saturation. The perimeter and interior channels have been sized for 100-year peak runoff flows.

The drainage channels may include riprap to protect the channels from erosion. At a minimum, riprap protection will be provided in the perimeter channels at bends and at connections points with interior channels. Riprap may also be included along portions of the perimeter channels that receive off-site flows and along the west face of the drainage berm protecting the west boundary of the expansion area. However, consideration will be given to alternatives to riprap. For example, drop structures within the channels could be used to flatten channel slopes and slow velocities sufficiently to make riprap generally unnecessary.


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9.8 Waste and Hazardous Materials Management A preliminary Spill Prevention, Control and Countermeasure (SPCC) Plan for project construction and the current SPCC Plan for facility operation are provided as Exhibit F. The SPCC Plan for project construction addresses fuels, lubricants, and hydraulic fluids expected to be used for construction equipment. Such equipment will be properly maintained to minimize leaks, and whenever warranted to prevent spills, vehicle maintenance will be performed off-site at an appropriate facility. The SPCC Plan for facility operation addresses the mineral oil that may be contained in each transformer, and it will be updated to address gasoline, diesel fuel, and waste lubricating oil upon installation of the tanks or drum for these materials. Each transformer, fuel tank, and drum installation includes full secondary containment as described in Section 4.6, Drainage Design. The preliminary SPCC Plan for project construction will be updated as necessary to reflect the actual practices employed by the construction contractor. The SPCC Plan for facility operation will be updated on a regular basis as new equipment is commissioned and turned over from construction to operations.

The mineral oil contained in each transformer does not normally require replacement, and any such replacement will be accomplished by either transporting the entire transformer off-site or by transferring the mineral oil to a tanker truck for transport off-site. Mineral oil disposal will be managed in accordance with the Waste Management Plan provided as Exhibit G.

The PV panels and inverters produce no waste during operation. However, the PV panels may include solid materials that are considered to be hazardous, such as cadmium telluride. To address management of such materials, the applicant’s contract with the selected PV panel manufacturer will include a provision requiring the manufacturer to receive and recycle or dispose of any broken or defective PV panels. Because such materials are in a solid and non-leachable state, broken PV panels will not be a source of pollution to storm water. Dust palliative, if used, and small amounts of herbicides will be stored on–site and will be provided with secondary containment if applicable. The facility does not present significant potential for introducing pollution to storm water, and operation of a solar PV facility is typically exempt from storm water discharge permitting based on Standard Industrial Code.

All use, storage, transport, and disposal of hazardous materials used in construction or operation of the facility will be in strict accordance with federal, state, and county laws, ordinances, and regulations. No extremely hazardous materials (i.e., governed under 40 Code of Federal Regulations 335) are anticipated to be produced, used, stored, transported, or disposed of as a result of the project. During construction and operation of the project, Material Safety Data Sheets (MSDS) for all applicable materials present on-site will be made readily available to on-site personnel.

During construction of the facility, non-hazardous construction debris will be generated. Such debris will be disposed in local landfills. During construction of the facility, sanitary waste will be managed using portable toilets located at reasonably accessible on-site locations. To support operation of the facility, the administration building is provided with a sanitary waste system including a septic tank and leach field.

Project Narrative Report - Sempra US Gas & Power, LLC

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