Industrial Stormwater: California Metals Capture

Up-Flo® Filter enabled a supplier to the aerospace and electronics industry to cut its discharge of metals and TSS to become compliant with environmental permits.

The Situation: 

In 2015 California introduced new limits on stormwater discharge from industrial facilities, placing stricter controls on the levels of pollutants that may be discharged on an ongoing basis or as a result of a single storm event.

Facilities require a discharge permit under the National Pollutant Discharge Elimination System (NPDES) permit program, and the new regulations mean that in order to obtain a permit businesses must demonstrate reduced discharge of controlled pollutants.

The Problem: 

The management team of a supplier to the aerospace and electronics industries was concerned that the stormwater effluent from its facility contained aluminum, zinc, iron and copper at levels above the new discharge limits. At the levels in question the business risked facing significant financial and legal penalties, as well as associated reputational damage.

The management team developed a Stormwater Treatment Action Plan, but as part of that plan they needed to identify treatment technologies that would meet their site’s specific needs.

The Solution: 

The management team identified Up-Flo® Filter as a potential solution, and they engaged Hydro International to undertake a characterization study of their stormwater effluent and to perform performance testing of the Up-Flo® Filter.

Runoff samples were sent to Hydro International’s hydraulics laboratory, where the samples were tested on the Up-Flo® Filter.


The pre-treatment and post-treatment samples were analyzed independently for metals, suspended solids, organic carbon, pH and nitrate/nitrite.

The Outcome:

Up-Flo Filter reduced discharge levels to beneath regulatory limits.

Performance testing of the site’s effluent revealed that Up-Flo Filter could reduce all of the effluent metals to beneath discharge limits, as well as reducing other pollutants:

Industrial Stormwater Treatment Data

  • Zinc capture of up to 97%
  • Aluminum capture of up to 95%
  • Iron capture of up to 92%
  • Copper capture of up to 89%


Incorporation of Up-Flo® Filter ensured that the management team could implement their Stormwater Treatment Action Plan effectively—and the risks of financial and legal penalties that had been facing them were removed.

Request your FREE Industrial Pollutant Removal Kit at hydro-int.com/samplekit

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