Track 2 at MuniCon 2025 brings you the latest advancements in stormwater treatment, specifically focusing on the emerging issue of 6PPD-quinone (6PPD-Q) and innovative strategies for managing this harmful tire-derived chemical. These sessions feature groundbreaking research, new best management practices (BMPs), and advanced techniques that are reshaping how we handle stormwater contaminants. From new detection methods to advanced treatment systems, Track 2 offers valuable insights for anyone working in stormwater management. 

Case Study: Post GULD Maintenance Assessment for Basic Treatment Devices 

Join Jay Holtz (Oldcastle Infrastructure) and Carla Milesi (University of Washington-Tacoma Center for Urban Waters) as they discuss the latest update to the Washington State Department of Ecology’s Technology Assessment Protocol (TAPE). This session will cover the results from a hydraulic testing procedure aimed at identifying maintenance intervals for filtration devices and provide data from the BioPod biofiltration system pilot program in Des Moines, WA. 

6PPD-Q: Stormwater Research, Methods Development, and Emergent Policies 

Shelby Giltner and Madison Rose Bristol (Washington State Department of Ecology) will provide an overview of 6PPD-Q and its impact on aquatic life, specifically coho salmon. Learn about ongoing research to develop BMPs that mitigate 6PPD-Q in stormwater and hear about policy developments designed to address this emerging chemical threat. This session will feature input from local governments, consultants, and Tribal representatives. 

Reducing 6PPD-Q Concentrations Using High-Performance Bioretention Soil Media (HPBSM) 

Curtis Hinman (Curtis Hinman & Associates) and Chelsea Mitchell (King County) will share results from research on the effectiveness of HPBSM in reducing 6PPD-Q concentrations in highway runoff. This session will cover how HPBSM can protect coho salmon and improve stormwater quality in urbanized areas heavily impacted by tire-derived contaminants. 

Non-Vegetated Bioretention Soil Media Study 

Aimee Navickis-Brasch and Mikala Lindgren (Evergreen StormH2O) present a study on Bioretention Soil Media (BSM) used without vegetation. The research evaluates treatment performance for metals, phosphorus, and 6PPD-Q in dry climates where irrigation systems aren’t feasible. This session will highlight the potential for alternative BSM designs in areas with limited water resources. 

Testing 6PPD-Q on the Snoqualmie Indian Tribe Reservation 

Kelsey Payne (Snoqualmie Indian Tribe) will discuss a baseline study on 6PPD-Q levels conducted on the Tribe’s reservation. This session will provide valuable data on BMPs such as bioswales and floating treatment wetlands, which are being tested to address 6PPD-Q contamination in the Tribe’s stormwater systems. 

The Birth of the 6PPD-Q Soil Extraction Method 

Thomas Chontofalsky and Fatima Alsinai (City of Tacoma) present the development of a novel extraction method for measuring 6PPD-Q in sediment. This innovative method will allow for more accurate monitoring of 6PPD-Q in urban waterways and inform future regulatory measures to address this emerging pollutant. 

6PPD-Q and PFAS Removal Using Regional Bioretention Systems 

Dylan Ahearn (Herrera Environmental Consultants) and Chelsea Mitchell (King County) will present a case study on a regional bioretention system designed to remove both 6PPD-Q and PFAS from stormwater. Learn how this innovative system is addressing contamination in Lake Whatcom and how the treatment design is improving stormwater quality on a regional scale. 

6PPD-Q Removal in Decant Facilities 

River Wan and Jeff Rudolph (Pierce County), alongside Shelby Giltner (Washington State Department of Ecology), discuss how Pierce County’s decant facility uses multi-stage treatment processes to reduce 6PPD-Q concentrations in stormwater catch-basin cleaning waste. This session will highlight the facility’s effectiveness in removing 6PPD-Q and its potential for application in other municipalities. 

Targeted Treatment for 6PPD-Q: King County’s Spatial Model 

Timothy Clark (Herrera Environmental Consultants) and Carly Greyell (King County) will share the development of a spatial model to predict where 6PPD-Q is most likely to enter the stormwater network. This model helps prioritize treatment locations, ensuring that resources are directed to the highest-impact areas and enabling multi-benefit stormwater projects. 

Development of a Passive Sampling Device for 6PPD-Q 

Christian Nilsen (Geosyntec Consultants), Rhea Smith (Washington State Department of Ecology), and Brent Paulter (SiREM) introduce a new passive sampling device designed for continuous monitoring of 6PPD-Q in surface waters. This session will cover the technology behind the device and its potential for long-term monitoring of this harmful chemical in stormwater systems. 

 

Don’t miss out on these groundbreaking sessions at MuniCon 2025! Track 2 is dedicated to addressing one of the most critical issues facing stormwater management today—6PPD-quinone. From detection methods to innovative treatment solutions, these presentations offer valuable tools and strategies for dealing with this emerging pollutant. Register now to secure your spot and dive deep into the science and solutions surrounding 6PPD-Q!