Repeat zinc and copper exceedances after sediment controls usually mean the dissolved fraction is passing through untreated. Here's how Smart Sponge® HM media and Abtech's catch basin and bulk formats close that gap for industrial permit holders.
Zinc and copper removal from industrial stormwater requires treating the dissolved metal fraction, not just settling out sediment, because both metals leach from galvanized surfaces, brake pads, roofing and process areas in a soluble form that filters and catch basins built for solids will pass straight through. Facilities that keep exceeding NPDES or MSGP benchmarks for zinc and copper after installing sediment controls are usually running into this exact gap.
Why Do Zinc and Copper Keep Showing Up After Sediment Controls Are in Place?
Sediment control media, sumps and hydrodynamic separators are built to capture particulates by size and weight. Zinc and copper that arrive already dissolved in runoff, rather than bound to a particle, pass through that kind of media because there is nothing to physically strain out. On industrial sites regulated under NPDES, MSGP and SWPPP requirements, this is the most common reason a facility can pass a visual inspection and still return a lab result above its benchmark. Metal recycling yards, fabrication shops and sites with outdoor equipment storage or galvanized structures are especially prone to this pattern because their metal sources are constant and weather-driven rather than tied to a single spill event.
Where the Metals Actually Come From
Galvanized roofing, fencing, HVAC housings and structural steel corrode gradually and release zinc into runoff every time it rains. Copper more often traces back to roofing, gutters, plumbing fixtures or brake-related debris tracked across paved yards. On a metal recycling or fabrication site, both metals can also originate directly from stockpiled scrap, cutting operations and uncovered process areas. Because these sources are diffuse and weather-dependent, a single storm event can carry a different metal load than the one before it, which is part of why repeat benchmark exceedances are so common at these facility types.
What Treats the Dissolved Fraction, Not Just the Visible Debris?
Smart Sponge® HM is the Abtech media built specifically for dissolved metals, including lead, zinc, copper, arsenic and selenium, along with phosphorus. Where standard Smart Sponge® media targets hydrocarbons and oil, Smart Sponge® HM is formulated to bind dissolved metal ions as water passes through it. Because Abtech's platform separates media from format, Smart Sponge® HM can be specified into whichever installation a site already has or is planning to add.
Matching Format to the Discharge Point
- Catch basin inserts (the custom-fabricated Ultra Urban® Filter) for sites where metals concentrate at individual storm drain inlets across a yard or paved area.
- Bulk Smart Sponge® HM media loaded into existing pressure vessels, skids, tanks or vaults where a facility already has infrastructure it wants to retrofit rather than replace.
- Smart Pak® and Smart Bags for vault or channel installations where space or access is limited.
- EOP end-of-pipe units for treating flow at a single discharge point before it reaches the outfall.
- Smart Skid systems, which are installed with pumps, pressure and flow controls, for sites needing a higher-flow, engineered polishing step rather than a purely passive format.
Several Smart Sponge® media types can also be combined in one system. A metal recycling yard dealing with both zinc runoff and a persistent oil sheen, for example, can pair Smart Sponge® HM with standard Smart Sponge® media in the same catch basin insert or vault, addressing both contaminant classes without running two separate treatment trains. Full details on how the formats fit different infrastructure are outlined on Abtech's media deployment options and installation formats page.
How Does a Site Confirm Which Format and Media Combination It Needs?
Every Abtech project begins with a site assessment that reviews the contaminants present, typical and peak flows, available space, effluent targets and maintenance access before any system is specified. Abtech follows the principle that the media follows the contaminant and the format follows the site, so the assessment comes before any product recommendation rather than after. For facilities that want confirmation before committing to a full installation, laboratory column testing on the customer's own water sample is available, with pilot testing for larger applications ahead of full-scale deployment. This sequence matters for metals treatment in particular, since the ratio of dissolved to total zinc or copper can vary by site and by season, and that ratio affects which media and format combination makes sense.
Frequently Asked Questions
Is zinc from galvanized surfaces treated the same way as zinc from process operations?
Both are dissolved zinc once they enter runoff, so Smart Sponge® HM targets the metal itself rather than its source. What differs is the flow pattern and concentration a site assessment needs to capture, since a galvanized roof drains differently than a scrap stockpile area.
Can one catch basin insert handle both zinc removal and general debris capture?
The custom-fabricated Ultra Urban® Filter is built to fit a wide range of catch basin shapes and sizes, and Smart Sponge® HM media can be specified inside it alongside the insert's TSS and debris capture function, so a single insert can address both objectives at one inlet.
Do we need pilot testing before installing metals treatment?
Not every project requires it. Abtech offers laboratory column testing on a customer's own water sample and pilot testing for larger applications, and whether that step is worthwhile depends on the site assessment findings and how variable the facility's metal loading is.
Does Smart Sponge® HM replace sediment controls we already have?
No. Sediment controls and Smart Sponge® HM address different fractions of the same runoff. Particulate-bound metals are still caught by solids control; Smart Sponge® HM is aimed at the dissolved fraction that passes through sediment-only systems.
What is the first step toward fixing a repeat zinc or copper exceedance?
Start with a site assessment that reviews the site's contaminant mix, flow patterns and discharge targets, since that determines whether a catch basin insert, bulk media retrofit or another format fits the facility. You can schedule a site assessment with Abtech to work through those specifics.