Project Description

Aluminum Extrusion Company, Pacific Northwest

Sapa Group is an international extrusion, anodizing and fabrication company with 23 locations in the US, Canada and South America. Beginning in 2013, Sapa Group began undertaking a process to upgrade stormwater pollutant control infrastructure at three of its pacific northwest facilities. As a result of this initiative, the company has come into full compliance with industrial stormwater benchmarks at two of its facilities, and a third will have treatment installed in 2017. The first of the three facilities has been granted a monitoring waiver for all regulated stormwater pollutants.

POLLUTANTS: TSS, copper, zinc, phosphorus


zinc b gone stormwater treatment


Sapa Group is an international extrusion, anodizing and fabrication company with 23 locations in the US, Canada and South America. Despite best efforts to control pollutants with catch basin inserts, rigorous source controls and strong structural best management practices, two of their sites in Portland, Oregon failed to meet the stringent stormwater quality benchmarks imposed by the 1200COLS Industrial General Permit, and triggered corrective actions for zinc, copper, phosphorus and TSS. Previous investments to incorporate downspout filtration from another manufacturer failed to produce any measurable improvement in stormwater quality at the outfalls.

At Sapa Extrusions Main Plant, a regional engineering consulting firm prepared a stormwater conveyance, collection and treatment design that incorporated 20,000 gallons of detention and an Aquip 210SBE enhanced stormwater filtration system. When the system was started up in 2013, the StormwateRx treatment system produced 100% compliance with effluent stormwater quality, being consistently below the benchmarks. In response, the plant was granted a monitoring waiver for all stormwater pollutants and was allowed to terminate monitoring for the rest of the permit cycle.

At a second of Sapa’s plants, stormwater compliance testing during the 2013-2014 rain season triggered corrective actions at one of its outfall for TSS, zinc and phosphorus. To reduce pollutant concentrations at this outfall, in 2016 the Company installed an Aquip 50SBE enhanced stormwater filtration system to come into compliance with water quality benchmarks. Also in 2016, the company took the initiative to install an Aquip 10PBE enhanced stormwater filtration system at a smaller outfall, in advance of requirements to do so.  This initiative reduced the cost of managing runoff from this outfall by allowing the use of a less stringent treatment sizing criteria following the City of Portland Stormwater Management Manual guidelines, and by reducing the administrative burdens of corrective actions.

Sapa Extrusions moved forward with plans to retrofit yet a third of its facilities with Aquip enhanced stormwater filtration in late 2016, again to avoid moving into a corrective action requirement at this facility.  StormwateRx staff worked with the design engineer to come up with an innovative approach to combine outfalls with minimal construction and operational interference, thereby reducing the cost of the project and, most importantly, minimizing disruption of production.  The facility is installing an Aquip 110SBE enhanced stormwater filtration system on the two main combined outfalls, an Aquip 10PBE enhanced filtration system on a loading dock outfall, and an Aquip Zinc-B-Gone Basic on one of the hotspot rooftop downspouts.  The systems were installed and operational during first quarter 2017.


100% benchmark compliance; monitoring waivers. The results at all Sapa facilities with StormwateRx treatment installed are exceptional, with discharge stormwater quality below the benchmarks. All plants with StormwateRx treatment that are eligible have received monitoring waivers for all pollutants.