SW3211203_Stormwater Narrative_20220223

Date: December 13, 2021
Project: BG Stewart Solar Farm, LLC
1510 Old Highway 74
Marshville, North Carolina 28103
Union County
PROJECT NARRATIVE
CYPRESS CREEK
RENEWABLES
The purpose of this narrative is to summarize the as -built improvements for the BG Stewart Solar Farm, LLC project ("Project"),
which was built in 2015; discuss post -construction drainage conditions and demonstrate compliance with NC DEMLR's post -
construction stormwater permitting requirements. Cypress Creek Renewables (CCR) performed an internal audit and discovered
that the project was missing said permit — i.e., it was not obtained by the previous Developer/Engineer prior to beginning
construction. The CCR Engineering Team verified that the project is in a State Post -Construction Stormwater Permitting
jurisdiction, gathered the available project documentation, completed the NC DEMLR stormwater management application
forms, and issued a fee payment check with the goal of bringing the operational solar facility into compliance.
The project is a 4.5-Megawatt (MW) AC (6.78 MW DC) solar power generation facility located on a 41.75-acre lease -controlled
area in Union County. The facility consists of fixed tilt solar photovoltaic (PV) panel tables supported on driven steel piles (posts)
and pad -mounted inverters. The solar PV system is connected to the Duke Energy Carolinas (DEC) utility electric grid at a Point
of Interconnection (P01), north of the main array fields (See As -Built ALTA Survey). No significant site grading was performed
— only minimal vegetation clearing, utility trenching, subgrade preparation for a gravel access drive and concrete equipment
pads. A chain link perimeter fence encloses the facility.
The solar site is functioning adequately as a Low -Density Project with stormwater released as dispersed flow. The project site
areas are completely vegetated and match pre -construction terrain, except for a gravel drive and concrete equipment pads. The
site's existing sloping topography (no grading per Civil Plan Sheet C-4) directs overland sheet flow drainage to surrounding
downstream areas - i.e., a Non -Jurisdictional Ditch to the north and an unnamed Intermittent Stream to the southwest. The
unnamed stream is a tributary flowing to Beaverdam Creek (WS-V; Yadkin Pee -Dee River Basin). The site generally consists
of three topographic areas: (1) a northeast portion of Parcel 1 that slopes radially from the mid -east boundary from an elevation
of 584 feet to 568 feet northwest to the Non -JD ditch; (2) a southeast portion of Parcel 1 that also slopes radially from 583 ft to
570 ft in the west and southwest directions; and (3) a westerly portion within Parcel 2 that primarily slopes southwest from the
joint mid -parcel boundary, from elevation 574 ft to 560 ft at the Intermittent Stream. Downstream vegetation areas provide
natural stormwater treatment and dissipation of runoff prior to discharging to the ditch/stream. Onsite, the grass areas beneath
the solar panels and between rows allow for rainwater infiltration, runoff dissipation, and dispersal as overland sheet flow.
The proiect does not meet the design criteria for a Disconnected Impervious System (DIS) since the project calculated
Disconnection Length is only 44.6% of the total solar panel width, which is below the minimum 80% threshold required by
NCDEQ Stormwater Design Manual Section E-6 (See BUA Calculations Package: Row Spacing: 18.17-ft; Solar Panel Width:
8.10-ft; Slope: 5.2%, average). Per the submitted Zoning Site Plan (PV Solar Racking Detail), the solar panel heights are below
10-ft; therefore, complying with Recommendation 6.
The CCR Operations and Maintenance (0&M) Team performs regular inspections on a quarterly basis. 0&M personnel perform
grass mowing; minor seeding/replanting of bare areas; debris and trash removal; panel washing/cleaning; onsite road repairs;
and electrical equipment testing. The submitted Operation & Maintenance Agreement will enhance and/or reinforce the
Maintenance Plan that is already in -place; thereby, meeting Post -Construction Stormwater Permit requirements for a Low -
Density project.
Cypress Creek Renewables, 5310 S. Alston Ave. Bldg. 300 Durham, NC 27510 919.240.4815