Please consider the following comments on the proposed amendments to the Virginia Erosion and Stormwater Management Regulation, 9VAC25-875. These are staff comments and do not represent an adopted position of the Fairfax County Board of Supervisors.

1) The change from an allowable phosphorus load of 0.41 lbs/ac/yr to 0.26 lbs/ac/yr essentially creates a new category of "grandfathered" projects for projects submitted prior to July 1, 2025. This needs to be accounted for by creating a parallel set of criteria throughout 9VAC25-875-580 and 9VAC25-875-590 to cover pre-July 1, 2025, plans that explicitly allow use of the 0.41 lbs/ac/yr phosphorus load, 2011 non-proprietary BMP specifications, and the 2011 VRRM for such projects.

2) 9VAC25-875-110.C provides for a determination of completeness of a plan within 15 days. For plans submitted prior to July 1, 2025, to be processed under the current criteria, there should be a requirement that they subsequently be determined complete.

3) For plans submitted prior to July 1, 2025, please consider a requirement that they be approved to show due diligence.

4) The reason the current regulations list the 15 non-proprietary BMPs by version and date is to provide a fixed set of design criteria to work from. The Virginia Stormwater Management Handbook should be referenced by date and/or version number in 9VAC25-875-590.B so that designers and owners are not faced with constantly changing design criteria.

5) For the reasons stated in comment #1, the reference to the Virginia Runoff Reduction Method: Instruction and Documentation, March 28, 2011, should be retained in 9VAC25-875-9999.

6) The proposed amendments to the regulations will require amendments to local ordinances. Because of the length of the process for developing/publishing/adopting these amendments to the regulations, please consider extending the effective date to January 1, 2026, so that jurisdictions administering VESMPs have adequate time to amend local ordinances.

7) To address the above comments I suggest the following language:

9VAC25-875-580.A.1

1. New development.

a. For plans submitted on or after July 1, 2025, the total phosphorus load of new development projects shall not exceed 0.26 pounds per acre per year, as calculated pursuant to 9VAC25-875-590.

b. For plans submitted prior to July 1, 2025, subsequently accepted for review, and approved by July 1, 2027, the total phosphorus load of new development projects shall not exceed 0.41 pounds per acre per year, as calculated pursuant to 9VAC25-875-590 in effect prior to July 1, 2025.

VAC25-875-580.B:

B. Compliance with subsection A of this section shall be determined in accordance with 9VAC25-875-590 except that for plans submitted prior to July 1, 2025, compliance with subsection A of this section shall be determined in accordance with 9VAC25-875-590 in effect prior to July 1, 2025.