Emerging stormwater treatment technologies (TAPE)

Stormwater treatment technologies are reviewed and certified by the Washington state Technology Assessment Protocol - Ecology — better known as the TAPE program.

2018 Update to TAPE Guidance Documents

Between versions: What changed and what stayed the same?

This is a general list of some of the major changes between the previous 2011 version of the TAPE guidance and the current 2018 version. Please note this list is not exhaustive.


  • New pre-approved testing facilities
  • Number of qualifying storms increased
  • TAPE fees increased
  • Nitrogen and bacteria added as screening parameters
  • Long detention guidance document added as an appendix
  • Requirement to submit data electronically (Excel or csv file)
  • Options for influent data that falls outside of the TAPE influent concentration range
  • Additional size categories for particle size distribution analysis
  • Requirement to measure accumulated sediment within the technology (where feasible)
  • Requirement to evaluate pollutant removal as a function of flow rate and bypass frequency over time
  • Pollutant removal as a function of flow rate analysis based on 90th percentile influent flow rate
  • Clarified discrete flow sampling method

Stayed the same

  • Definition of qualifying storm
  • Required pollutants
  • Performance goals
  • Statistical analysis methods
  • QA/QC requirements
  • Use Level Designations

Pre-Approved Technology Evaluation Facilities

The below pre‐approved facilities have adequate pollutant concentrations and flows that enable manufacturers to use as a monitoring site. Using these facilities will reduce the overall cost of monitoring a device and allows smaller companies to participate in the TAPE program. These sites have experienced, on‐site monitoring staff to perform the sampling and analysis activities that also make the evaluation more efficient.

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University of New Hampshire Stormwater Center
Durham, NH

James Houle, CPSWQ

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Stormwater Technology Testing Center
Portland, OR

John Lenth

Evaluating new technologies

We review engineering reports on the performance of new technologies and provide our use-level designations in the approved technologies table.

Board of External Reviewers (BER)

To help us with evaluations, a paid Board of External Reviewers (BER) provides national expertise in stormwater treatment technologies. The BER acts in a direct review capacity to provide us recommendations about each new technology and how well it performs.

Each application to TAPE and C-TAPE will be assigned a minimum of three members from the BER to provide detailed review and comment on the applications, Quality Assurance Project Plans (QAPPs), and Technical Evaluation Reports (TERs).

Performance goals

We evaluate several types of permanent stormwater treatment systems for specific sampling criteria, site and technology information, quality assurance and quality control measures, target pollutants, and evaluation report content.

These types of treatments are intended to achieve:

Use Level Designations (ULDs)

General Use Level Designation (GULD): Technologies whose evaluation report demonstrates confidently it can achieve Ecology's performance goals

GULD technologies may be used in Washington and are subject to Use Level Designation conditions. We will only accept written comments on technologies that have received GULD.

Conditional Use Level Designation (CULD): Technologies that show high likelihood of meeting performance goals.

CULD allows continued use of the technology for a specified preiod of time. The vendor and/or developer must conduct field testing during the permitted time for most CULD technologies. These technologies are considered likely to attain a General Use Level.

Units that are in place do not have to be removed after the specified time period. Use is subject to the Use Level Designation conditions.

Pilot Use Level Designation (PULD): Promising technologies that need more verification testing

PULD allows limited use of the technology to allow field testing to be conducted. PULD technologies may be installed provided that the vendor and/or developer agree to conduct field testing based on the TAPE at all installations. See the PULD notice of intent form for more information on PULD technologies. 

Approved technologies

The following table lists the devices that have received a designation through the TAPE process.

In addition to our certification, local jurisdiction approval is required (and not guaranteed) for installation of treatment technologies we have evaluated and given a use designation.

Note: We have changed the term in the table from Enhanced Treatment to Metals Treatment. The only change is in the terminology and all the requirements are still in effect for Metals Treatment BMPs. The underlying treatment requirements remain in place and all devices that previously had a GULD for Enhanced Treatment now have a GULD for Metals Treatment.

This table walks viewers through an excel spreadsheet of all the contact information for the approved stormwater technologies certified through the TAPE program.

Functionally equivalent technologies

We have approved the following technologies as functionally equivalent to best management practives (BMPs) included in our stormwater management manuals. These technologies did not pass through TAPE.