How storm runoff filtration systems work, which media treats which pollutant, and which format fits an existing basin, vault, vessel or skid.
Storm runoff filtration systems pass runoff through a filtering medium before it reaches a storm drain outlet or a water body, and the right system depends on the pollutants in your water and the space your site offers. Sediment filters hold particulates, while dissolved metals, phosphorus and hydrocarbons need media chosen for them. We make Smart Sponge® media and the equipment that holds it in the path of water.
What Do Storm Runoff Filtration Systems Treat?
Rain and snowmelt that cannot soak into the ground run across pavement and roofs. According to the US EPA NPDES stormwater program, that runoff picks up trash, chemicals, oils and sediment, and communities, construction companies and industries use best management practices (BMPs) to filter pollutants out or prevent them at the source. The same program regulates some stormwater discharges from municipal separate storm sewer systems (MS4s), construction sites and industrial sites.
Filtration is only one family of BMP. The Minnesota Stormwater Manual on filtration BMPs describes filtration practices as effective at attenuating suspended sediment and the pollutants associated with that sediment. That is the key limit to plan around. A filter built for particulates does little for pollutants that travel dissolved in the water.
Which Media Matches Which Pollutant?
Our rule is that the media follows the contaminant and the format follows the site. Start by naming each pollutant in your permit or lab results and whether it is dissolved or particulate. Then match the media.
| Pollutant of concern | Smart Sponge® media | What it targets |
|---|---|---|
| Oil, grease and hydrocarbons | Standard Smart Sponge® | Hydrophobic, oil-attracting media that binds hydrocarbons into a stable solid |
| Dissolved lead, zinc, copper, arsenic, selenium; phosphorus | Smart Sponge® HM | Dissolved metals and phosphorus |
| E. coli and coliform bacteria | Smart Sponge® Plus | Antimicrobial media for stormwater applications |
| Dissolved organics that raise total organic carbon | Smart Sponge® AC | Dissolved hydrocarbons and organic compounds |
| PFAS | Smart Sponge® Quanta™ | Available for pilot and full-scale deployments |
| Suspended solids and sediment | Smart Sponge® Sediment and TSS media | Particulates, through a high-porosity structure |
When one pavement area sheds more than one class of pollutant, several media can be combined in one system. A fueling area with metal-bearing runoff, for example, may call for hydrocarbon media and HM media together. We state what each medium targets and do not promise removal rates, because results depend on each site's water.
Which Format Fits Your Site?
Format is a separate decision from media. It comes down to what infrastructure you already have, how much water arrives at once, and whether power is available.
| Format | Where it fits | Power needed |
|---|---|---|
| Ultra Urban® Filter insert | Existing catch basins and deck drains; custom-fabricated to each basin's geometry, no excavation | Passive, no pumps or power |
| Bulk Smart Sponge® media | Existing pressure vessels, skids, tanks and vaults | Depends on the host system |
| Smart Pak®, Smart Bags and end-of-pipe units | Vaults, channels, outfalls and discharge points | Passive |
| Skimmers and booms | Floating oil, fuel and sheen at docks, sumps and outfalls | Passive |
| Smart Skid and Abtech vessels | Packaged treatment with pumps, pressure and flow controls | Uses pumps |
If your drainage ends in catch basins, an insert is usually the least disruptive start; our guide to choosing a drop-in stormwater drain filter walks through that selection. If you already own a vault or vessel, bulk filtration media for stormwater vaults, pressure vessels and skids lets you put treatment into that structure instead of building new. Our stainless steel Ultra Urban® Filter inserts carry a 20-year warranty on the hardware only; it does not cover media, media life, removal performance or other formats.
Why Do Sediment Controls Leave Pollutants Behind?
Sumps, screens and settling hold what can be caught physically. Dissolved zinc, copper, phosphorus and some hydrocarbons pass through, because they are part of the water rather than riding on particles. This is where repeated benchmark exceedances at industrial sites often persist after housekeeping and sediment controls are in place.
The EPA National Menu of BMPs for stormwater notes that some individual practices may not be effective alone but can provide a key function in combination with others. We read that as a design principle: keep pretreatment for trash and sediment, and add media for the dissolved share downstream of it.
Green infrastructure is the other route. The EPA page on stormwater management practices at EPA facilities lists green roofs, bioretention areas, swales and constructed wetlands. These need land, soils and vegetation. Where a site is fully paved and cannot give up space, a retrofit into the existing drains and vaults is often the practical alternative.
What Does a Practical Selection Process Look Like?
Every project we take on starts with a site assessment covering contaminants, flows, available space, effluent targets and maintenance access. Larger applications can add laboratory column testing on a sample of your own water, followed by pilot testing. Airports and municipalities give a sense of the range: our Ultra-Urban® Filter inserts were selected for an airport stormwater program to treat deicing-season runoff across paved airfield catchments. You can also browse more on water treatment and compliance topics on our blog, and the page on a hydrocarbon filter for storm drains covers the oil side in detail.
FAQ: Storm Runoff Filtration Systems
Do storm runoff filtration systems need power?
Not the passive formats. Catch basin inserts, bags, packs, skimmers and booms work without pumps or power. Smart Skid systems are the exception, because they use pumps, pressure and flow controls.
Can one system treat metals and oil together?
Yes. Several Smart Sponge® media can be combined in one system, so hydrocarbon media and HM media can work on the same runoff when a site carries both.
Is a sediment filter enough for a permit exceedance?
Only if the pollutant is particulate. If the exceedance involves dissolved zinc, copper or phosphorus, a sediment filter is not designed to hold it, and media that targets the dissolved fraction is the better match.
How do I know which media my water needs?
Compare your permit pollutants with lab results that separate dissolved from particulate fractions, then test on your own water. Column and pilot testing show how a medium behaves with your chemistry and flow, which published tables for other sites cannot.
Related resources
- Choosing a Drop-In Stormwater Drain Filter: A Step-by-Step Selection Process
- Bulk Filtration Media for Stormwater Vaults, Pressure Vessels and Skids
- Water Treatment & Compliance Blog — Abtech Industries
- Hydrocarbon Filter for Storm Drains | Ultra-Urban® Filter — — Abtech Industries
- Deck Drain Filtration Inserts — Abtech Industries
- Deck Drain Filtration Inserts — Abtech Industries
- Catch Basin Insert Filter for Stormwater: How Ultra Urban® Filter and Smart Sponge® Media Work Together