HomeMy WebLinkAboutPB Packet 3 - Carrowmoor Solar sketch plan - DEC letter- did not have permission to combine
February 16, 2023
Nicole Stephen
LaBella Associates
300 State Street, Suite 201
Rochester, New York 14614
RE: Carrowmoor Solar Project
DEC Facility ID#: 7-5030-00199
Town of Ithaca, Tompkins County
Jurisdiction Determination
Dear Ms. Stephen:
The New York State Department of Environmental Conservation (DEC) has reviewed the information that
you submitted regarding the above referenced project. According to the provided materials, the project
consists of the installation of a ground-mounted solar array at 1340 Mecklenburg Road. In addition to the
installation of the solar array, the project includes the construction of an access road from Mecklenburg
Road to the array.
Based upon the review of your inquiry, DEC has the following comments:
PROTECTION OF WATERS
An unnamed tributary of Cayuga Lake (NYS Water Index #: Ont-66-12-P 296-76-2, Class C, non-
navigable) is located within the identified parcel, however, it appears the work will be avoiding any impacts
to this waterbody therefore a Protection of Waters Permit is not required for the proposed work.
If a permit is not required, please note, however, the project sponsor is still responsible for ensuring that
work shall not pollute any stream or waterbody. Care shall be taken to stabilize any disturbed areas
promptly after construction, and all necessary precautions shall be taken to prevent contamination of the
stream by silt, sediment, fuels, solvents, lubricants, or any other pollutant associated with the project.
FRESHWATER WETLANDS
The project site is not within a New York State protected Freshwater Wetland. The project sponsor should
contact town officials and the United States Army Corps of Engineers (USACE) Auburn Field Office, at
(315) 255-8090, however, for any permitting they might require. Please note that if a permit from the
USACE is required for the proposed work, a Section 401 Water Quality Certification may be required from
DEC.
STATE-LISTED SPECIES
No records of sensitive resources were identified by this review. The absence of data does not necessarily
mean that rare or state-listed species, natural communities or other significant habitats do not exist on or
adjacent to the proposed site. Rather, our files currently do not contain information which indicates their
presence. For most sites, comprehensive field surveys have not been conducted. We cannot provide a
RE: Carrowmoor Solar Project Date: 2/16/2023
DEC Facility ID#: 7-5030-00199
Town of Ithaca, Tompkins County
Jurisdiction Determination
Page 2 of 2
definitive statement on the presence or absence of all rare or state-listed species or significant natural
communities. Depending on the nature of the project and the conditions at the project site, further
information from on-site surveys or other sources may be required to fully assess impacts on biological
resources.
STATE POLLUTANT DISCHARGE ELIMINATION SYSTEM (SPDES)
Soil disturbances of one or more acres of land from construction activities must obtain permit coverage
under the NYSDEC SPDES General Permit for Stormwater Discharges from Construction Activities (GP-
0-20-001) by submitting a Notice of Intent and developing & implementing a Stormwater Pollution
Prevention Plan. For further information please consult with Julie Melancon in DEC’s Division of Water at
315-426- 7550 or review the NYSDEC Stormwater webpage. Additionally, please see the attached solar
panel stormwater permitting guidance document. If the project does not meet ALL criteria for Scenario 1,
including alignment of solar panels along the contour, the SWPPP must address post-construction
stormwater practices designed in accordance with the sizing criteria identified in the New York State
Stormwater Management Design Manual.
CULTURAL RESOURCES
We have reviewed the statewide inventory of archaeological resources maintained by the New York State
Museum and the New York State Office of Parks, Recreation, and Historic Preservation. These records
indicate that the project is not located within an area considered to be sensitive with regard to
archaeological resources. For more information, please visit the New York State Office of Historic
Preservation website at http://www.nysparks.com/shpo/.
OTHER
DEC recommends contacting the New York State Department of Public Services in regards to the
proposed project and any requirements under Article VII or Article 10 of the New York State Public Service
Law.
Other permits from this Department or other agencies may be required for projects conducted on this
property now or in the future. Also, regulations applicable to the location subject to this determination
occasionally are revised and you should, therefore, verify the need for permits if your project is delayed or
postponed. This determination regarding the need for permits will remain effective for a maximum of one
year unless you are otherwise notified. Applications may be downloaded from our website at
www.dec.ny.gov under “Programs” then “Division of Environmental Permits.”
Please contact this office if you have questions regarding the above information. Thank you.
Sincerely,
Jonathan Stercho
Deputy Regional Permit Administrator
Division of Environmental Permits, Region 7
Telephone No. (315) 426-7444
Enclosure
cc: J. Melancon, R7 DOW
M E M O R A N D U M
TO: Regional Water Engineers
FROM: Robert Wither, Chief, South Permit Section
SUBJECT: Solar Panel Construction Stormwater Permitting/SWPPP Guidance
DATE: April 5, 2018
Issue
The Department is seeing an increase in the number of solar panel construction
projects across New York State. This has resulted in an increase in the number of
questions on Construction General Permit (CGP) and Stormwater Pollution Prevention
Plan (SWPPP) requirements from design professionals because the current CGP (GP-
0-15-002) does not include a specific reference to the SWPPP requirements for solar
panel projects in Tables 1 and 2 of Appendix B. To address this issue, the Division of
Water (DOW) has developed the following guidance on CGP/SWPPP requirements for
the different types of solar panel projects.
Scenario 1
The DOW considers solar panel projects designed and constructed in accordance with
the following criteria to be a “Land clearing and grading for the purposes of creating
vegetated open space (i.e. recreational parks, lawns, meadows, fields)” type project as
listed in Table 1, Appendix B of the CGP. Therefore, the SWPPP for this type of project
will typically just need to address erosion and sediment controls.
1. Solar panels are constructed on post or rack systems and elevated off the
ground surface,
2. The panels are spaced apart so that rain water can flow off the down gradient
side of the panel and continue as sheet flow across the ground surface*,
3. For solar panels constructed on slopes, the individual rows of solar panels are
generally installed along the contour so rain water sheet flows down slope*,
4. The ground surface below the panels consist of a well-established vegetative
cover (see “Final Stabilization” definition in Appendix A of the CGP),
5. The project does not include the construction of any traditional impervious areas
(i.e. buildings, substation pads, gravel access roads or parking areas, etc.),
6. Construction of the solar panels will not alter the hydrology from pre -to post
development conditions (see Appendix A of the CGP, for definition of “Alter the
hydrology…”). Note: The design professional shall perform the necessary site
assessment/hydrology analysis to make this determination.
*Refer to Maryland’s “Stormwater Design Guidance- Solar Panel Installations”
attached for guidance on panel installation.
**See notes below for additional criteria.
Scenario 2
If the design and construction of the solar panels meets all the criteria above, except for
item 6, the project will fall under the “All other construction activities that include the
construction or reconstruction of impervious area or alter the hydrology from pre-to post
development conditions, and are not listed in Table 1” project type as listed in Table 2,
Appendix B of the CGP. Therefore, the SWPPP for this type of project must address
post-construction stormwater practices designed in accordance with the sizing criteria in
Chapter 4 of the NYS Stormwater Management Design Manual, dated January 2015
(Note: Chapter 10 for projects in NYC EOH Watershed). The Water Quality Volume
(WQv)/Runoff Reduction Volume (RRv) sizing criteria can be addressed by designing
and constructing the solar panels in accordance with the criteria in items 1 – 4 above,
however, the quantity control sizing criteria (Cpv, Qp and Qf) from Chapter 4 (or 10) of
the Design Manual must still be addressed, unless one of the waiver criteria from
Chapter 4 can be applied. **See notes below for additional criteria.
** Notes
- Item 1: For solar panel projects where the panels are mounted directly to the ground
(i.e. no space below panel to allow for infiltration of runoff), the SWPPP must address
post-construction stormwater management controls designed in accordance with the
sizing criteria in Chapter 4 of the NYS Stormwater Management Design Manual, dated
January 2015 (Note: Chapter 10 for projects in NYC EOH Watershed).
- Item 5: For solar panel projects that include the construction of traditional impervious
areas (i.e. buildings, substation pads, gravel access roads or parking areas, etc.), the
SWPPP must address post-construction stormwater management controls for those
areas of the project. This applies to both Scenario 1 and 2 above.
cc: Carol Lamb-Lafay, BWP
Dave Gasper, BWP
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Maryland Department of the Environment
Stormwater Design Guidance – Solar Panel Installations
Revisions to Maryland’s stormwater management regulations in 2010 require that environmental site
design (ESD) be used to the maximum extent practicable (MEP) to mimic natural hydrology, reduce
runoff to reflect forested wooded conditions, and minimize the impact of land development on water
resources. This applies to any residential, commercial, industrial, or institutional development where
more than 5,000 square feet of land area is disturbed. Consequently, stormwater management must
be addressed even when permeable features like solar panel installations exceed 5,000 square feet
of land disturbance.
Depending on local soil conditions and proposed imperviousness, the amount of rainfall that
stormwater requirements are based on varies from 1.0 to 2.6 inches. However, addressing
stormwater management does not mean that structural or micro-scale practices must be constructed
to capture and treat large volumes of runoff. Using nonstructural techniques like disconnecting
impervious cover reduces runoff by promoting overland filtering and infiltration. Commonly used with
smaller or narrower impervious areas like driveways or open roads, the Disconnection of Non-Rooftop
Runoff technique (see pp. 5.61 to 5.65 of the 2000 Maryland Stormwater Design Manual1) is a low
cost alternative for treating runoff in situations like rows of solar panels.
When non-rooftop disconnection is used to treat runoff, the following factors should be considered:
• The vegetated area receiving runoff must be equal to or greater in length than the disconnected
surface (e.g., width of the row of solar panels)
• Runoff must sheet flow onto and across vegetated areas to maintain the disconnection
• Disconnections should be located on gradual slopes (≤ 5%) to maintain sheetflow. Level
spreaders, terraces, or berms may be used to maintain sheetflow conditions if the average slope
is steeper than 5%. However, installations on slopes greater than 10% will require an engineered
plan that ensures adequate treatment and the safe and non-erosive conveyance of runoff to the
property line or downstream stormwater management practice.
• Disconnecting impervious surfaces works best in undisturbed soils. To minimize disturbance and
compaction, construction vehicles and equipment should avoid areas used for disconnection
during installation of the solar panels.
• Groundcover vegetation must be maintained in good condition in those areas receiving
disconnected runoff. Typically this maintenance is no different than other lawn or landscaped
areas. However, areas receiving runoff should be protected (e.g., planting shrubs or trees along
the perimeter) from future compaction.
Depending on the layout and number of panels installed, the disconnection of non-rooftop runoff
technique may address some or all of the stormwater management requirements for an individual
project. Where the imperviousness is high or there is other infrastructure (e.g., access roads,
transformers), additional runoff may need to be treated. In these situations, other ESD techniques or
micro-scale practices may be needed to provide stormwater management for these features.
Example 1 – Using Non-Rooftop Disconnection Where the Average Slope ≤ 5%
Several rows of solar panels will be installed in an existing meadow. The soils within the meadow are
hydrologic soil group (HSG) B and the average slope does not exceed 5%. Each row of panels is 10
feet wide and the distance between rows is 20 feet. The rows of solar panels will be installed
according to Figure 1 below. In this scenario, the disconnection length is the same as the distance
between rows (20 feet) and is greater than the width of each row (10 feet). Therefore, each row of
panels is adequately disconnected and the runoff from 1.0 inch of rainfall is treated.
Figure 1. Typical Installation - Slope ≤ 5%
Example 2 – Using Non-Rooftop Disconnection Where the Average Slope ≥ 5% but ≤ 10%
Several rows of solar panels will be installed in an existing meadow. The soils within the meadow are
hydrologic soil group (HSG) B and the average slope is greater than 5% but less than 10%. Each row
of panels is 10 feet wide and the distance between rows is 20 feet. The rows of solar panels will be
installed as shown in Figure 2 below. The disconnection length is the same as the distance between
rows (20 feet) and is greater than the width of each row (10 feet). However, in this example, a level
spreader (typically 1 to 2-foot wide and 1 foot deep) has been located at the drip edge of each row of
panels to dissipate energy and maintain sheetflow.
Discussion
To meet State and local stormwater management requirements, ESD must be used to the MEP to
reduce runoff to reflect forested conditions. While all reasonable options for implementing ESD must
be investigated, minimally, the runoff from 1 inch of rainfall must be treated. In each of the examples
above, there may be additional opportunities to implement ESD techniques or practices and reduce
runoff that should be explored. However, simply disconnecting the runoff from the solar panel arrays
captures and treats the runoff from 1.0 inch of rainfall. Where imperviousness is low and soil
conditions less optimal (e.g., HSG C or D), this may be sufficient to completely address stormwater
management requirements. In more dense applications or in sandy soils, additional stormwater
management may be required.
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Conclusion
The primary purpose of Maryland’s stormwater management program is to mimic natural hydrologic
runoff characteristics and minimize the impact of land development on water resources. Any land
development project that exceeds 5,000 square feet of disturbance, including solar panel projects,
must address stormwater management. However, for solar panels, stormwater management may be
provided in a cost-effective manner by disconnecting each row of panels and directing runoff over the
vegetated areas between the individual rows.
Resources
1 2000 Maryland Stormwater Design Manual, Volumes I and II, MDE, October 2000
(http://www.mde.state.md.us/programs/Water/StormwaterManagementProgram/MarylandStormwaterDesignMa
nual/Pages/Programs/WaterPrograms/SedimentandStormwater/stormwater_design/index.aspx)
Figure 2. Typical Installation – Slope ≥ 5% but ≤ 10%
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