LIDMIX™ and LIDMAT™ are post-construction stormwater Best Management Practices (BMPs) that were developed to address National Pollutant Discharge Elimination System (NPDES) industrial and non-industrial permit requirements. LIDMIX™ is a media that can be used in storm drain inserts and inlet and downspout filters. LIDMAT™ is a version of the technology where the media is contained in a permeable geotextile fabric. Both LIDMAT™ and LIDMIX™ are patent protected technology.

One of the challenges of treating heavy metals such as zinc (Zn), copper (Cu), and lead (Pb) is that they are often found in high concentrations that must be reduced to very low discharges. Our testing has shown reductions of copper, zinc, and lead concentrations from over 100 mg/l to as low as almost 5 µg/l. The results of testing from field experiments at the USDA Beltsville Agricultural Research Center (BARC) where LIDMAT™ was used to treat runoff from a metal-clad building and the surrounding parking lot are shown below. The product is in a modular configuration so that it can be deployed around inlets at industrial activities and non‐industrial activities, along pipelines, roadways, storage, and manufacturing areas.

The geotextile can be biodegradable and seeds to produce specialized vegetation can be added to the media to uptake metals and stabilize the surrounding area. The product is lightweight and can easily be customized in the field, inspected, transported, maintained, and disposed of properly. The media can also be used independently and added to bioretention cells, and chamber and vault systems in order to increase system performance for metals and nutrient removal.


  • Highly efficient and predictable reductions of Heavy Metals (Zinc, Copper, Lead, Iron, Aluminum), below Industrial General Permit Numeric Action Levels (NALs).
  • Flexible, modular, and customizable configuration
  • Low Impact Development for industrial stormwater treatment
  •  Eight years of rigorous laboratory and field testing by the University of Maryland at College Park
  •  Biodegradable version is available
  • The LIDMIX™ media has a projected life of over four years. A typical cycle for replacement of LIDMAT™ is one to two years, dependent on the field conditions.