AES CE appreciates the opportunity to comment on GM No. 22-2012. We have observed many technical and grammatical errors in the document and recommend that guidance memo be updated and reissued for public comment.
AES CE seeks clarification on the “expedited process” that DEQ is referencing. Is this the current DEQ 45-day expedited review process or is DEQ referencing the proposed streamlined review process per GM22-2011?
A permanent vegetative cover should be established on all denuded areas not otherwise permanent stabilized. See Minimum Standard #3, 9VAC25-840-40 3, and Standard and Specification 3.32 (Permanent Seeding).”
A timeline for the application of initial soil stabilization is identified in this section; however, there are no clear timelines for re-stabilization of previously stabilized but not established denuded areas that do not exhibit excessive erosion. AES CE seeks clarification on whether there is a required timeline for previously stabilized yet not established denuded areas or if these areas, although not established, are considered stabilized and no additional stabilizing measures are necessary.
AES CE seeks clarification on the basis of consideration (i.e., baseline studies) for determining ground mounted solar panels as “unconnected impervious surface”? AES CE recommends a formal study be conducted that evaluates ground surfaces during construction, including vegetated and non-vegetated surfaces, with regard to the issue of erosion concerns associated with ground mounted solar panels. Erosion concerns may be associated with vegetation management under the solar arrays during construction, which may become irrelevant once uniform permanent vegetation is established. AES CE recommends conducting additional studies and evaluating these considerations before implementing drastic design alterations and requirements that may not resolve the underlying issue of erosion.
AES CE requests the DEQ define the term “storm event” in terms of duration and rainfall amount. A clear definition of a storm event would aid in determining rain-sensing technology sensitivity settings. Additionally, AES CE recommends encouraging a dynamic tilt method to disperse rainfall over a larger surface area, reducing both the volume of the impact and the area affected. Tracking systems cannot achieve a vertical position, as DEQ has referenced, but can be set to stow at their maximum tilt angle. AES CE requests the ability to further work with the DEQ on determining tracking system angle variability when considering stormwater calculations and best practices during these storm events.
AES CE recommends the inclusion of the U.S. Department of Agriculture Natural Resources Conservation Services Web Soils Survey for reference to hydric soil group information to prevent the utilization of outdated data.
AES CE recommends reconsidering how this is outlined on the cover sheet as large-scale projects will typically consist of multiple properties and property owners. This information is best provided in a table format for clarity and ease of reference.
AES CE requires clarity on what constitutes an offsite support activity. This is not defined in either GM22-2011 or GM22-2012 and additional information is necessary to understand what type of activity would fall into this category.
AES CE requires clarity on what equation is being referenced in this section. The equation components are provided but the equation is not included under this section.