MODERATOR: Donnie Seward, AECOM
Estimating the Local Effects of Off-Site Water Quality Compliance
- Marcus Aguilar, Research Scientist, Virginia Tech
Water quality trading has been proposed as a more economically efficient means of meeting stormwater quality goals by allowing for payment of “off-site” treatment in-lieu of treating runoff at a development site. The Virginia Stormwater Management Program (VSMP) provides a mechanism for off-site compliance with nutrient water quality criteria by allowing developers to purchase nutrient credits from nutrient banks in the same (or adjacent) eight-digit hydrologic unit (HU-8) in-lieu of constructing on-site stormwater best management practices (BMPs).
As nutrient banks have been constructed in various watersheds across Virginia, the purchase of off-site credits has become a more prevalent practice, resulting in a lack of water quality treatment in urban areas. This presents two issues for local government agencies (i.e. VSMP administrators): first, watersheds draining to local urban streams are being developed without the BMPs necessary to mitigate water quality impacts, and second, this forgone treatment prevents local governments from demonstrating progress towards non-nutrient total maximum daily load waste load allocations (TMDL WLAs).
The objective of this presentation is to demonstrate the potential impact of the off-site compliance program to local governments by simulating land development in Virginia localities and estimating the cost incurred on the locality when BMPs are not constructed on development sites where they would otherwise be required.
The results of this study quantify the tradeoff that occurs with the use of off-site compliance and provides a means of developing local regulations that account for the impacts of off-site compliance on local urban waterways.
Asset Management for MS4 Compliance
- Dr. Clay Hodges, Assistant Professor, Virginia Tech
- David Hurst, VHB, Program Manager
Asset management systems for stormwater infrastructure are often desired by municipalities and transportation agencies for creating and tracking maintenance work orders, budget planning, and a general understanding of their system, but an asset management system can also be used to track MS4 compliance. Numerous requirements of the MS4 Six Minimum Control Measures can be accomplished or made more efficient by taking advantage of tracking tools in an asset management system. Some of the ways an asset management system could be used to assist in MS4 compliance include illicit discharge detection and elimination (IDDE), mapping stormwater infrastructure, prioritizing assets for good housekeeping, and tracking in general.
This talk will explain how to enhance an asset management system for MS4 compliance, present cases studies on how systems are helping agencies comply with their respective MS4 permits, and review the development process and implementation strategies.
Although there are many drivers for creating an asset management system the most important aspect is creating a system framework that can be used to track, plan and report MS4 permit and enforcement requirements. A robust asset management system can allow users to collect data in the field while also updating data in the office and be easily converted into tables for annual reporting. Development of the asset management system requires forward-thinking to understand future permit requirements and infrastructure needs, but once a system implemented, it can be an efficient tool that helps reduce the cost for MS4 compliance while working in coordination with other tools.
Using 360 Degree Image Technology to Support Stormwater Management
- Ryan O'Banion, Associate, Hazen and Sawyer
Co-Author: Joseph Arizzi
Comprehensively documenting the condition of stormwater controls and potential retrofit sites can be challenging. Written documentation can sometimes incorporate biases of the field technician, while simple photographs may be tedious to catalog, miss key elements, or be challenging for someone not directly involved in the inspection to understand.
To combat these issues, Hazen is currently using innovative 360-degree image technologies to more comprehensively capture the condition of stormwater controls and better document potential retrofit sites in Fairfax County, VA, Washington, DC, and Boston, MA. These spherical images instantaneously capture the entire scene around the camera, rather than just a single direction. When viewed with appropriate software, a fully immersive and interactive environment is experienced by the viewer, with the ability to pan to or zoom into any location within line of sight from the point the image was taken.
This presentation will discuss how 360-degree image technology can be used to support stormwater management. It will exhibit example imagery and virtual tours of common stormwater facilities including bio-retention and underground detention. Presentation attendees will also gain an understanding of the technology and software required to implement this approach in their own workflows, including the collection of imagery, post-processing, and procedures for incorporating additional information into the 360-degree views.