Project Success through Full-Scale Infiltration BMP Testing

Date / Time:
Tuesday, Oct 16 1:35pm to 2:05pm
Meeting Room 7-8 (Upper Level)
Track / Session:
Making Stormwater BMPs Work Track / Guidance

This presentation is a forward-thinking discussion of what sizing of infiltration Best Management Practices (BMPs) may be like in the future as more is learned about the performance of infiltration BMPs. The presentation explains the current method for infiltration testing and infiltration BMP sizing (focused on Southern CA). After this discussion, the pros and cons of the existing process will be discussed. One of the cons will be the focus of this presentation. This con is the difficulty in accurately sizing infiltration BMPs based on the currently promoted practices. The innovative concept of full-scale infiltration testing will be discussed as one possible solution to the current issue of infiltration BMPs often being over or under-sized. Mr. Lee will present an example project (Van Nuys Boulevard Great Street – City of Los Angeles) that utilized full-scale infiltration sizing for drywells will be discussed to share the potential benefits along with practical takeaway information that the audience can incorporate into future projects to improve the accuracy of infiltration BMP sizing.

The focus of the presentation is on the concept of full-scale infiltration testing utilized for project design to improve the accuracy of infiltration BMP sizing. Mr. De Jong will share data related to infiltration through drywells and other infiltration BMP types to share. Mr. Lee has experience on the previously mentioned project that included the innovative method of conducting full-scale infiltration testing prior to final design to maximize the cost-effectiveness of the infiltration BMPs proposed on the project.

Another main feature of the presentation will be addressing the disconnect between current LID and stormwater quality guidance and actual field performance for infiltration BMPs.

By considering full-scale infiltration testing, projects can include more accurately sized infiltration BMPs instead of extremely over or under-sized infiltration systems which is common place in today’s infiltration BMP sizing process. The presentation will cover the perspectives from the design engineer, geotechnical engineer, and contractor.

The overarching theme of the presentation will be how to more effectively design and size infiltration systems to make the goals of LID more easily achievable. The theme of the presentation is to encourage infiltration for a more sustainable water supply. The presentation concludes with concrete examples of how these ideas can be incorporated into projects currently in design to make an immediate positive impact.

Mr. De Jong has extensive experience presenting technical topics focused on stormwater to audiences including: civil engineers, public agencies, geotechnical engineers, and landscape architects. The inclusion of a specific project case study by Mr. Lee is an interesting example of this process being executed on a high-profile project. The subject project is one of the 15 Great Streets projects announced by Los Angeles Mayor Eric Garcetti in 2014 (

Primary Speaker:
Bill DeJong, Torrent Resources

Mr. DeJong is an engineer with Torrent Resources and has a B.S. in civil engineering from Cal Poly San Luis Obispo. Bill’s career has been focused on stormwater management and land development engineering for the past 12 years. Bill has been involved on stormwater quality for projects within over 100 cities throughout Southern California. In his current role, Bill is focused on stormwater infiltration and provides technical expertise in the siting, design, and construction of engineered drywells to civil geotechnical, and municipal professionals.

Supporting Speaker 1:
Daniel Lee, Geosyntec Consultants