Recycling facilities operating under industrial NPDES stormwater permits — particularly MSGP Sector N — routinely see benchmark exceedances for zinc, copper, and lead because conventional sediment-only BMPs miss the dissolved metal fraction that sweeping and berms cannot intercept. This guide

Heavy metals reductions at recycling facilities stall when stormwater BMPs target only particulate-bound metals and ignore the dissolved fraction that passes straight through sediment controls. Scrap metal and materials recycling yards generate runoff that carries zinc, copper, lead, and other regulated metals in both forms — particulate-bound to fine sediment and truly dissolved in the water column — and the split between those two fractions determines which treatment layers actually move your benchmark numbers. Understanding that split is the first step toward a BMP stack that keeps your NPDES industrial stormwater permit in good standing without overwhelming your maintenance crew.

Why Recycling Yards Keep Failing Metal Benchmarks After Source Control

Scrap metal and materials recycling facilities are classified under MSGP Sector N and equivalent state industrial general permits precisely because their outdoor operations generate stormwater with elevated metal concentrations. The sources are everywhere on a working yard: exposed ferrous and non-ferrous scrap piles weather and corrode between storms, shredder residue carries fine metallic dust across paved surfaces, vehicle fluids from crushed cars contribute oil and trace metals, and galvanized roofing or structural surfaces leach zinc with every rainfall. When a storm event hits, all of that material mobilizes into runoff. The critical compliance problem is that metals in yard runoff do not behave as a single category. A portion binds to suspended sediment particles — that fraction responds to TSS capture through settling, berms, and sediment filters. But a meaningful share of zinc, copper, and lead travels in dissolved form, fully in solution. Dissolved metals pass through sediment controls without being captured. A facility can sweep its yard weekly, maintain perimeter berms, and deploy sediment bags at every drain and still see benchmark exceedances in its quarterly discharge monitoring reports — because none of those measures intercept dissolved metals. That is the gap that drives repeat exceedances and triggers corrective action requirements under the permit. See <a href="https://abtechindustries.com/">Read more on this website</a>.

The Two-Phase Metal Problem: Particulate and Dissolved

Effective heavy metals reduction at a recycling facility requires a BMP stack that addresses both phases. Source control — covering piles, sweeping frequently, routing drainage away from active processing areas — reduces the total metal load entering the stormwater system. Sediment capture at catch basins and sumps intercepts the particulate-bound fraction. But dissolved metals require a treatment medium that can chemically or physically bind them from the water column as flow passes through. This is where media selection matters. A high-porosity sediment filter that excels at TSS capture does not necessarily target dissolved zinc or copper. Contaminant-specific media formulations engineered for dissolved metals work differently — they interact with the metal ions in solution rather than simply straining out particles. For a recycling yard running a multi-pollutant discharge profile (metals plus hydrocarbons from vehicle fluids, plus sediment from shredder residue), the most efficient BMP architecture combines TSS capture, dissolved metals treatment, and hydrocarbon capture within the same catch basin insert, rather than requiring separate infrastructure for each.

Smart Sponge® Media: Contaminant-Specific Targeting at the Catch Basin

Smart Sponge® is a passive filtration media engineered by Abtech Industries to target challenging contaminants — including heavy metals, hydrocarbons, PFAS, bacteria, nutrients, sediment, and TSS — from flowing stormwater without pumps, power, or costly infrastructure upgrades. For recycling facilities, the relevant media formulations address the full pollutant profile that drives NPDES benchmark exceedances: dissolved metals including lead, zinc, copper, arsenic, chromium, and mercury; suspended solids and sediment; and hydrocarbons from vehicle fluids and equipment leaks. The media deploys inside an Ultra-Urban® Filter, a drop-in insert sized to fit existing catch basins. No excavation, no new infrastructure, no power connection — the insert drops into the basin already in the ground. Because different sites present different mixes of contaminants, flow conditions, and discharge requirements, Smart Sponge® media formulations can be selected and combined to address multiple treatment objectives within a single system. A recycling yard with elevated zinc and copper readings alongside hydrocarbon sheen can configure an insert that targets all three within the same basin footprint. Flow performance is a practical requirement for any catch basin BMP at an industrial yard. A media that restricts flow causes bypass during storm events, which defeats the treatment purpose. Smart Sponge® sustains flow rates up to 40 GPM per square foot with under 1 PSI of back pressure — which means the insert handles storm flows without backing up the drain or requiring constant intervention from maintenance staff. The media is also low-maintenance by design, not maintenance-free; inserts require periodic inspection and media exchange, but the system does not demand the active upkeep of pump-dependent or chemical-dosing alternatives.

Hydrocarbon Co-Benefit: Addressing Vehicle Fluid Runoff in the Same Insert

Recycling yards that process end-of-life vehicles, equipment, or fluid-containing materials generate hydrocarbon-laden runoff alongside metals. Oil, grease, and fuel residues contribute to sheen and degrade receiving water quality — and they are regulated under the same NPDES permit that governs metals discharge. Smart Sponge® media is hydrophobic and oil-loving by design: it binds hydrocarbons into a stable solid, keeping them captured rather than releasing them back into the water column as flow conditions change. That behavior means a single Ultra-Urban® Filter insert can address both the dissolved metals fraction and the hydrocarbon fraction of a yard's stormwater discharge, reducing the number of separate BMP measures a facility needs to maintain.

BMP Stack for MSGP Sector N Facilities: Where the Ultra-Urban® Filter Fits

No single BMP eliminates the need for a layered approach. The Ultra-Urban® Filter with metals-targeting Smart Sponge® media is most effective as the final treatment layer in a BMP stack that begins with source control and sediment management. The table below outlines how each layer addresses the two-phase metal problem and where the catch basin insert adds the treatment that upstream controls miss.

| Evidence | Recorded figure |

| --- | --- |

| Specialized water filtration technology designed for marine environments forms | 30 |

| Smart Sponge® is a passive filtration media engineered by Abtech Industries to | 40 |

| Smart Sponge® media sustains flow rates up to 40 GPM per square foot with under | 40 |

| Evidence | Recorded figure |

| --- | --- |

| Specialized water filtration technology designed for marine environments forms | 30 |

| Smart Sponge® is a passive filtration media engineered by Abtech Industries to | 40 |

Frequently Asked Questions

Why do we keep seeing zinc and copper exceedances even after improving our yard sweeping and sediment controls?

Sweeping and sediment controls target particulate-bound metals — those attached to fine solids that can be physically strained or settled out. Zinc and copper also travel in dissolved form, fully in solution, and dissolved metals pass through sediment filters without being captured. Addressing benchmark exceedances for these metals typically requires adding a treatment layer — such as a catch basin insert with contaminant-specific media — that can interact with dissolved metal ions in the water column, not just strain out particles.

What metals does Smart Sponge® media target?

Smart Sponge® heavy metals media targets lead, mercury, arsenic, chromium, zinc, copper, and other metals using contaminant-specific media formulations. Because different sites present different discharge profiles, media can be selected and combined within a single Ultra-Urban® Filter insert to address the specific metals driving benchmark exceedances at your facility.

Will the Ultra-Urban® Filter insert handle storm flows without backing up our drains?

Smart Sponge® media sustains flow rates up to 40 GPM per square foot with under 1 PSI of back pressure. That flow performance is a core design requirement — a BMP that restricts flow causes bypass during storm events and defeats the treatment purpose. The insert is sized to fit existing catch basins, and Abtech's site assessment process accounts for your catchment area and expected flow conditions when configuring the system.

Does the insert require power, pumps, or new infrastructure?

No. The Ultra-Urban® Filter is a passive, drop-in system. It fits into existing catch basins without excavation, power connections, or costly infrastructure upgrades. That retrofit-friendly design is particularly relevant for facilities that need to add a treatment layer quickly in response to benchmark exceedances or corrective action requirements without a capital construction project.

Can one insert address both metals and hydrocarbons from vehicle fluid runoff?

Yes. Smart Sponge® media formulations can be selected and combined within a single insert to address multiple treatment objectives — including dissolved metals and hydrocarbons — within the same catch basin footprint. The media is hydrophobic and oil-loving, binding hydrocarbons into a stable solid, while the metals-targeting formulation addresses the dissolved fraction. This multi-contaminant configuration is well-suited to recycling yards that process end-of-life vehicles or fluid-containing equipment.

How much maintenance does the system require?

Smart Sponge® systems are low-maintenance by design, not maintenance-free. Inserts require periodic inspection and media exchange — the frequency depends on your site's pollutant loading and flow conditions, which is part of what a site assessment helps determine. Because the system is passive and does not rely on pumps or active components, maintenance demands are significantly lower than active treatment alternatives, which is a practical consideration for facilities managing maintenance budgets alongside compliance obligations.

Will adding a catch basin insert guarantee that we meet our permit benchmarks?

Smart Sponge® supports NPDES compliance, but permit outcomes depend on site conditions, pollutant loading, the full BMP stack in place, and the determination of your permitting authority. No single BMP guarantees benchmark compliance — the Ultra-Urban® Filter is most effective as part of a layered approach that includes source control and sediment management upstream. Abtech's consultative process is designed to help you build a defensible, documented BMP addition matched to your facility's actual discharge profile.

How do we get started with a site assessment?

Abtech's team responds within one business day to site inquiries. The process starts with your discharge monitoring data, catchment layout, and permit requirements — not a generic product recommendation. You can schedule a site assessment or contact an expert directly through Abtech Industries to discuss your facility's specific metals and stormwater challenge.

Heavy Metals Reductions at Recycling Facilities: A Stormwater BMP Guide for NPDES Permit Holders