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Sakioka Farms Business Park-Phase 1

Oxnard, California



Fisher Construction Group


Delane Engineering, Inc. 


Sam Hill & Sons, Inc.


Summer 2021

Technical Description:

(32) Filterra® Internal Bypass Curb-Chambers

The Sakioka Farms Business Park is a master-planned industrial and business park on a 430-acre parcel located in Oxnard, California. The site is being developed in phases over an extended period, allowing for various uses in response to evolving market conditions. One of the first phases of development was a 75-acre parcel of land for a 1.5 million-square-foot fulfillment center for an e-commerce company. 

Due to the inability to infiltrate stormwater on-site, engineers specified a competitor's proprietary biofiltration along the campus streets and parking lots to capture and treat stormwater. This system used vaults and adjacent catch basins with curb inlets to manage peak flows. Contech was allowed to review the plans and offered an alternative solution that would save a significant amount of money and make installation much easier. 

Rather than using a biofiltration system with adjacent catch basins, Contech proposed using the Filterra bioretention system in the Internal Bypass Curb Plus Chamber Configuration, allowing for a single structure vs. two structures.  Filterra also provided a smaller media bed footprint because of its 175"/hr media infiltration rate.

Thirty-two Filterra units of various sizes were provided, with the largest being 14' x 8'. Custom chamber sizes were needed to accommodate larger pipes into the Filterra from a desilting basin and outlet pipes to the storm drain as required by the City of Oxnard. Contech Stormwater Design Engineers worked with Delane Engineering and Encompass Consultant Group on the sizing of all the systems, including the bypassing of peak-flows.

The Filterra vaults were custom-made per the site specifications, with installation taking place over three months.  A Contech Field Representative was on sight to support Sam Hill & Sons throughout the installation process.  Sam Hill & Sons set each system with an excavator. The larger Filterra systems were shipped minus the media, so the installation equipment would be easier to set each piece. The contractor added the media after the vaults were set using "Super Sacks."

"Contech's Filterra product allowed the Sakioka Industrial Business project to be completed in a drastically reduced timeline by modifying the original stormwater design," said Sam Hill of Sam Hill and Sons excavating. "Contech's team was able to modify their standard Filterra design to eliminate the majority of the cast-in-place structures, which saved installation time in the end. The project ran into delays from unforeseen conditions and conflicts, but Contech's product was ready for installation when the time came.  If the project wasn't modified from cast-in-place catch basins with Filterra's, it would have put the project into potential liquidated damages.  If saving time is saving money, I recommend Contech's Filterra product for almost any project."

Technical Description:

(32) Filterra® Internal Bypass Curb-Chambers


800-338-1122 |
Project #: 651,998


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