Oldcastle PerkFilter™ Media Filtration Device

Conditions of use

1. All configuration options for the PerkFilter Media Filtration Device (using ZPC Filter Media) are approved for pollution reduction. Selection of a specific configuration is the responsibility of the project designer.  
2. Use of a PerkFilter Media Filtration Device (using ZPC Filter Media) does not exempt a project or site from required flow control requirements, operations and maintenance requirements, or other applicable requirements of the Stormwater Management Manual.
3. For use in the public right-of-way, the following conditions must be met: 
   • Units must meet City of Portland street design requirements, including but not limited to H-20 vehicle load rating, non-slip surface, and American with Disabilities Act tolerances specific to surface grates or vault lids.
   • The O&M Plan must call for an assessment during the two-year warranty period of project-specific maintenance requirements and frequencies.
4. Oldcastle-certified providers should be utilized for activation, inspection and maintenance of the system, unless otherwise trained and certified by the manufacturer. 

Project designer responsibilities

1. Ensuring that the conditions of use are met.
2. Ensuring that the project meets all applicable requirements of the Stormwater Management Manual, such as the Stormwater Infiltration and Discharge Hierarchy, in order to use PerkFilter Media Filtration Device (using ZPC Filter Media).
3. Ensuring that the design and installation of the units are appropriate for the project goals, site conditions, long-term maintenance requirements, and any other site-specific design requirements on private property or for use in the public right-of-way.
4. Sizing units to meet the current Stormwater Management Manual presumptive design approach and pollution reduction requirements. The pollution reduction capacity is flow-based and assumes a treatment flow intensity of 0.19 inches per hour, 5 minute time of concentration, and a 0.90 runoff coefficient using the Rational Method with treatment rates based upon the Washington State Department of Ecology General Use Level Designation approved flow rates, in lieu of the manufacturer's standard flow rate. The treatment capacities for PerkFilter Media Filtration Device (using ZPC Filter Media) units, based on those assumptions, are provided in Table 1. For sites with different times of concentration, different rainfall intensities may be appropriate. See the 2014 City of Portland Stormwater Management Manual Chapter 1.3.4, pages 1-40 for additional information.
    

5. Each site plan must undergo Oldcastle review before the City of Portland can approve the unit(s) for site installation. A letter that certifies that the project has been designed to manufacturer's specification must be submitted to the Bureau of Environmental Services prior to the appropriate design milestone. For public improvements, including public works permits, the letter must be submitted to the Bureau of Environmental Services prior to 60% plan review. For installation on private property, the letter must be submitted prior to building permit plan approval. The project designer is highly encouraged to work with Oldcastle prior to the appropriate review milestone to maximize placement and performance of the unit(s).
6. If the project designer wishes to vary from these conditions of approval, the project designer must use the Performance Design Approach.  
    

Approval conditions

1. The Bureau of Environmental Services may at any time suspend or revoke approval if the performance of the technology does not meet performance criteria, or if the performance criteria change due to the local, state, or federal pollution reduction standards.  
2. If any changes, updates, or revisions have occurred to the PerkFilter (using ZPC Filter Media), the applicant must obtain Washington State Department of Ecology Technology Assessment Protocol General Use Level Designation certification and re-apply following submission guidelines in effect at the time of application.  

More information on the product can be found on the manufacturer's product website. 

Approved: November 2016 under the requirements of the 2014 Stormwater Management Manual.