Project overview
Stormwater runoff from roadways and other surfaces often contain particles contaminated with polycyclic aromatic hydrocarbons (PAHs), which eventually settle to the bottom of stormwater detention ponds. Due to known health and environmental hazards, PAHs are a regulated toxic substance. As ponds age and dredging is necessary, this material presents a challenge for disposal.
Researchers will identify the major sources of PAH contamination to stormwater detention pond sediments around the state of Minnesota. Sediment samples will be taken from about 20 ponds at various sites and will be analyzed for 32 different PAH compounds. The team will also conduct some preliminary analysis of methods to treat sediments, such as composting and aerobic biodegradation.
Research findings
- PAH-contaminated sediments were found not only in Twin Cities area ponds but also in ponds in Greater Minnesota.
- Sediment from 35% of the ponds exceeded Minnesota’s Industrial Soil Reference Value, meaning they were so polluted that the sediment from these areas would need to be disposed of in a secure landfill.
- PAHs in Minnesota stormwater pond sediments came from a variety of sources, including gasoline, diesel engine emissions, and coal tar sealcoats.
What does this mean for Minnesota?
This project raises the statewide issue of PAH pollution in our stormwater. This raises awareness for stormwater practitioners, who will have to seek treatment options for contaminated ponds as well as raise the funds to do so.
Reports and presentations
- Executive summary 2017 .pdf
- Final report 2017 .pdf