Project overview
Wise investment in the selection and implementation of stormwater practices requires the determination of the source and magnitude of water contaminants. This determination is fundamentally tied to the measurement of concentrations from rainfall and snowmelt events. Equipment and instrumentation to collect samples during runoff events are expensive and have considerable installation and maintenance costs. Improvement in monitoring techniques addresses all of the research program priorities but the project is especially well suited to characterize urban stormwater. Discrete samples are taken using different sampling protocols. Important concentration values can easily be missed with these protocols. This issue can be addressed by using low-cost, nearly continuous water quality sensors. The use of these sensors has great potential, but more work is needed to implement them in field applications.
The goal of this project is to improve the selection and effectiveness of stormwater practices by evaluating first flush concentrations and the event mean concentrations obtained from different sampling methods. This goal will be achieved by compiling and analyzing first flush and event mean concentrations from urban and highway surfaces, by evaluating different discrete sampling methods to determine event mean concentrations and by advancing the use of inexpensive and nearly continuous sensor data to determine pollutographs.
Research findings
- Pollutant wash-off patterns varied by site and by storm, which can make predictions difficult.
- Volume-based samplers are more accurate than time-based samplers for estimating pollutant concentrations.
- Electrically conductive sensors can help estimate concentrations for certain pollutants.
What does this mean for Minnesota?
This project will aid stormwater practitioners in better understanding how contaminants enter and move through stormwater infrastructure, which will help practitioners prevent pollutants entering Minnesota’s waterways.
Reports and presentations
- Final report 2022
- Project update 2021 .pdf