Stormwater Technology Performance Verification

G.R. Williams, J.H. Neate
Good Harbour Laboratories,

Keywords: stormwater management, innovative technologies, performance verification, data quality, informed decisions


Resilient, sustainable water management is a continuum that both supports and depends upon decisions and subsequent actions based on reliable measurement, analysis and feedback. Society expects project proponents and solution providers to deliver results that reduce or eliminate negative ecological impacts, provide superior performance, and/or use fewer resources relative to conventional practices. However, the adoption of innovative technologies is inherently risky. Technological innovations comprise new products and processes, as well as significant technological changes to these products and processes. By definition, an innovative technology may not have a track record of performance. It is therefore reasonable to assume that, in the absence of a performance track record, the deployment of effective innovative infrastructure solutions would benefit from comprehensive approaches that incorporate evidence-based performance benchmarking and verification. VerifiGlobal, an international platform that provides a critical mass of performance measurement and verification capability across multiple sectors, and Good Harbour Laboratories, an accredited performance testing organization with in-depth stormwater technology expertise, are collaborating to undertake performance benchmarking and verification in the stormwater area, following the requirements of the new ISO 14034 Environmental Technology Verification (ETV) standard. Through this collaboration, important lessons are being learned regarding the technical and market challenges for acceptance, adoption and use of innovative stormwater technologies. The primary technical challenge is data quality. Although established and approved stormwater test protocols exist, many of these are inconsistent, with different specifications and inherent data quality issues. For example, one protocol requires that the final performance of a device be reported as the weighted average of the performance at five different flow rates. Another requires that the data be reported with a 95% confidence interval. Yet another requires that solids removal be reported based on a calculation using the amount of mass recovered from the device after a single test run. While all of these protocols have strengths, they also have weaknesses, which must be understood. Another challenge is how the results of performance testing and verification are reported and interpreted by stormwater technology end users and whether or not they will comply with water quality objectives. While developers and design engineers may propose the installation of stormwater devices on specific development sites, it can be difficult for permitting and approvals agencies to assess whether a particular device is adequate at different flow rates. Furthermore, the reported removal rates of sediments and other materials can differ depending on the technology and the manufacturer. This presentation will address these challenges and other issues in generating the type and quality of data that decision makers need when evaluating and selecting innovative stormwater treatment technologies. It will also propose solutions to support the thesis that defining performance objectives for innovative stormwater solutions and verifying their performance helps municipalities, utilities and other water sector stakeholders make informed choices, while also benefiting technology companies seeking market acceptance of their innovative solutions. Illustrative examples will be provided.