Virginia Regulatory Town Hall View Comments

Department of Environmental Quality

State Water Control Board

Guidance Document Change: The Virginia Stormwater Management Handbook, Version 1.0 (Handbook) provides guidance to implement water quantity and water quality criteria in the Virginia Erosion and Stormwater Management Regulation, 9VAC25-875, effective July 1, 2024. The Handbook replaces nine guidance documents, listed below, that the Department of Environmental Quality (DEQ) plans to rescind effective July 1, 2025: 1. Virginia Erosion and Sediment Control Handbook, Third Edition, 1992 2. Virginia Stormwater Management Handbook, First Edition, 1999 3. Guidance Document on VSMP Site Inspection Strategies 4. Guidance Document on Utilization of Nonpoint Nutrient Offsets 5. Guidance Memo No. 14-2002 Implementation Guidance for the 2009 General Permit for Discharges of Stormwater from Construction Activities, 9VAC25-880 6. Guidance Memo No. 14-2014 Implementation Guidance for Section 47 (time limits on applicability of approved design criteria) and Section 48 (grandfathering) 7. Guidance Memo No. 15-2003 Postdevelopment SW Mgmt Implementation Guidance for Linear Utility Projects 8. Guidance Memo No. 22-2011 Streamlined Plan Review for Construction Stormwater Plans and Erosion and Sediment Control Plans submitted by a Licensed Design Professional and reviewed by a Dual Combined Administrator for Erosion and Sediment Control and Stormwater Management 9. Guidance Memo No. 22-2012 Stormwater Management and Erosion & Sediment Control Design Guide The reason that the guidance documents will be rescinded effective July 1, 2025, through a separate Town Hall notice, is that they have been incorporated into the Handbook to reduce complexity and improve the ease of use. A one-year transition period allows plans and permit applications submitted between July 1, 2024 and June 30, 2025 to utilize either the existing manuals, handbooks and guidance or the Virginia Stormwater Management Handbook, Version 1.0. The Handbook is available as a Portable Document Format (pdf) file and online at https://online.encodeplus.com/regs/deq-va/index.aspx. Due to the large file size and number of pages in the Handbook, DEQ recommends using the web-based version to review it and submit comments. Chapters, best management practice specifications, and other information from the Handbook may be downloaded from the website as pdf files. Written comments on the Handbook may be submitted directly through the enCodePlus website that is hosting the handbook, as well as through the Town Hall website, and by email to the contact address provided with this notice. Instructions for submitting comments through the host website are available from the “Comment” link on the webpage banner. DEQ will use comments received during this forum and after the Handbook becomes effective to maintain its content consistent with the process for updates and revisions described in Chapter 1: Introduction. DEQ formed a Stakeholders Advisory Group (SAG) to help develop the Handbook and its content. The SAG met 12 times between July 2022 and October 2023. Members of the SAG were provided an opportunity review and provide feedback on a draft version of the Handbook during November 2023. DEQ reviewed and revised the draft Handbook based on the feedback SAG members provided. Handbook Version 1.0 reflects those revisions. Two Excel spreadsheets with comments SAG members submitted on the draft version of the Handbook, and responses to those comments, are available from the DEQ website at: https://www.deq.virginia.gov/our-programs/water/stormwater/stormwater-construction/handbooks under the Virginia Stormwater Management Handbook, Version 1.0 banner.

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3/26/24 5:29 pm

Commenter: William Sledjeski, PSS, Soil Tech Inc.

Appendix C clarifications

Determination of HSG: A critical design value which is often improperly evaluated and subsequently used to generate an inaccurate system design. The designer is directed to the NRCS or local soil survey to determine HSG but never a follow up as required "In all cases the designer should evaluate the existing soils to ensure a proper HSG designation." The NRCS soil survey program was not created to evaluate 1/3 acre parcels. Soil surveys identifying URBAN LAND having HSG D designations can be evaluated based on surface textures and placed into a useful category, according to the USDA DEQ guidelines. There are VA licensed professionals able to determine the proper designation based on a site evaluation, if regulatory agencies alllowed. There are many systems, presently installed which are based on improper HSG designations which is the designers choice.

Infiltration Testing: At present, a qualitative approach to determining another critical design value is the falling head test. It is not a quantitative method of determining hydraulic conductivity. "This constant rate of infiltration is sometimes called the soil's permeability but is technically defined as the saturated hydraulic conductivity (Ksat)." Ksat should be used for design. The infiltration rate determined by the suggested methods and the falling head result in different values. It seems with all the three decimal values in the spreadsheets that the engineering community would be better served using intrinsic soil properties and site evaluated HSG values. (if not at least use a 6" head rather than 24" to determine infiltration rate)

CommentID: 222375