MTD Evaluation Process

Chapter 32 of the 2022 Acts of Assembly (HB1224) provides for the certification and use of a proprietary BMP only if another state, regional, or national program has verified its nutrient or sediment removal effectiveness and all of such program’s established test protocol requirements were met or exceeded.

To have a manufactured treatment device (MTD), also referred to as a proprietary BMP, evaluated by the Virginia Department of Environmental Quality (DEQ):

  1. Complete the Proprietary BMP Registration Statement* (Word)
  2. Submit the completed registration statement along with supporting documents to DEQ’s Rebeccah Rochet (

The DEQ will review submissions and if approved, assign the applicable percent TP removal efficiency. After the percent removal has been assigned, this value will be added to the Virginia Stormwater BMP Clearinghouse and can be used to meet the water quality design criteria requirements.

MTDs approved by DEQ are listed by category:

  • Approved Hydrodynamic Devices (Practice 16),
  • Approved Filtering Devices (Practice 17), or
  • Prior-approved Devices: Prior-approved Hydrodynamics and Prior-approved Filters — Proprietary BMPs on the prior-approved lists may only be used to meet the TP water quality requirements of VSMP regulation for stormwater management plans submitted prior to January 1, 2022.

*All information submitted to DEQ will be made publicly accessible to all interested parties. If the MTD/proprietary BMP is approved, the submitted registration statement and other information reviewed by DEQ will be posted on the Virginia Stormwater BMP Clearinghouse website.