Improving stormwater quality at source using catch basin inserts.

Area of Science:

• Environmental Engineering
• Water Quality Management
• Urban Hydrology

Background:

• Stormwater runoff carries pollutants, impacting water bodies and drainage systems.
• Best management practices (BMPs) like catch basin inserts (CBIs) mitigate urban runoff pollution.
• Limited data exists on pollutant characteristics, hindering BMP design optimization.

Purpose of the Study:

• To investigate the effectiveness of a novel geotextile CBI in improving stormwater quality.
• To analyze the physicochemical characteristics of pollutants captured by CBIs in different urban settings.
• To provide insights for enhancing CBI design and operation for stormwater pollutant removal.

Main Methods:

• Installation of non-woven polypropylene geotextile CBIs in side entry pits at residential and commercial sites.
• Collection and analysis of influent and effluent stormwater for BOD, COD, TSS, and PO4-P.
• Characterization of captured solids, including particle size distribution, SEM imaging, and heavy metal analysis (Cu, Fe, Ni, Pb, Zn, Cd).

Main Results:

• CBIs achieved significant pollutant removal: BOD (90%), COD (88%), TSS (88%), and PO4-P (26%).
• Heavy metal concentrations in water were below guideline values.
• Residential areas had finer particles and higher specific surface area, likely from traffic; commercial areas had higher heavy metal concentrations in solids.

Conclusions:

• Geotextile CBIs are effective in reducing gross pollutants and improving stormwater quality at the source.
• Pollutant characteristics vary between urban land uses, influencing BMP performance.
• Long-term monitoring of CBI performance in diverse locations is recommended for further optimization.