Functionally Equivalent Stormwater Technologies: An Eye on the Future

How far back into history does the first stormwater management system go? Our civilization has been implementing systems using low-impact development principles for hundreds of years. With some of these original techniques still in use today,¹ one can wonder how there’s any room for new technologies in the industry.

Like any other industry, stormwater management professionals are constantly striving to be more accurate, more efficient, more resilient to entropy. When new technology emerges, it goes through a vetting process to ensure that it’s appropriate for filling whatever role it’s trying to fill. At AQUALIS, we keep our ears to the ground to stay educated on any new products and technology trends.

This can be quite beneficial to you, the person who’s ultimately responsible for stormwater compliance. For instance, you may need to put up straw wattles around storm drains in a parking lot to temporarily protect the storm drain system from getting construction runoff. If we find a qualified product that is more sustainable, just as effective, and less expensive, we’ll implement it and pass the savings onto you.

Functionally Equivalent to T.A.P.E.

Across the many territories where our clients depend on us, there are different protocols for accepting new stormwater technology. Washington State’s Technology Assessment Protocol- Ecology (TAPE) program approves emerging stormwater devices to keep pace with this rapidly evolving industry. TAPE certification requires testing and approval by an external board–but not every technology. If deemed “functionally equivalent,” some control measures can be implemented without going through the program.

To be approved for use without TAPE certification, the Stormwater Control Measure (SCM) must be designated as functionally equivalent. Each SCM that avoids the TAPE process is paired with an already approved, existing technology. For example, TAPE-approved BMP C233 represents a silt fence, BMP C235 are straw wattles, and alternative options for each type can be found through Ecology in the lists of equivalent devices.

Here are a few examples of the 29 devices (and counting) granted an exemption from the TAPE process. Keep in mind that we don’t necessarily endorse these items; we are simply providing examples of the types of technologies coming down the pipeline:

Erosion Eel

Are you looking for a sustainable alternative for building a retaining wall? Created by American Erosion Control, LLC,  the Erosion Eel is marked as functionally equivalent to BMP C235: Straw Wattles. The construction scenario highlighted above is therefore highly relevant to this product. It can be used in place of rock check dams, silt fences, compost socks, and wattles. Filled with recycled tires, the Erosion Eel is self-weighted and doesn’t require staking at most sites.  Ecology’s formal letter of approval for the device explains how it should be used.

Muscle Wall

Produced by a company of the same name, Muscle Wall acts as a flood control measure. If there was news of an oncoming hurricane (stay safe, North Carolina) and your business has a history of flooding, this BMP might help keep you dry. The functionally equivalent BMP is C233: Silt Fences, and they are pre-approved for any of the wall sizes (up to eight feet). Use these for flood control, coastal erosion, and containment as well as stormwater management.

GeoCurve Inlet Filter

We spend an awful lot of time repairing curb inlets and catch basins, because nothing on earth is immune to erosion and catch basins are on the front line. Often, you’ll see filters placed into the opening to catch trash and, sometimes, even chemicals. The GeoCurve consists of a wire frame and filter media in a lengthy “C” shape. It’s touted as an easy-to-install (or replace) equivalent to BMP C220 Storm Drain Inlet Protection.

More important than whether a SCM is TAPE-approved or rated as functionally equivalent is if it is the best fit for your site. These are just examples of emerging stormwater technologies functionally equivalent to TAPE, which has approved dozens of devices in each of its qualifying categories. If you’d like to learn more, or have questions about implementing emerging technology in your own state, don’t hesitate to reach out to us!

1: https://www.ncbi.nlm.nih.gov/pubmed/23552234

2: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-permittee-guidance-resources/Emerging-stormwater-treatment-technologies

3: https://www.erosioneel.com/

4: https://ecology.wa.gov/DOE/files/e6/e6e1c9c8-5b5d-4a63-85d3-70420519f940.pdf

5: http://www.musclewall.com/

6: https://ecology.wa.gov/DOE/files/b5/b500045b-8ddb-466f-9ff8-09ef83cff398.pdf

7: https://www.geosolutionsinc.com/products/swppp-construction-curb-inlet-filter.html