Stormwater Goes Mainstream: ASTM Launches E64, a New Committee Devoted Specifically to All Things Stormwater Control Measures

ASTM International (ASTM) has been a recognized leader in consensus standard development by many different industries for more than 100 years now.  ASTM’s newest technical committee, E64, is devoted specifically to developing standards applicable to the broad class of stormwater management practices known as stormwater control measures (SCMs).  ASTM is not entirely new to the world of stormwater and SCMs.  Prior to the formation of E64, a subcommittee working under the umbrella of the C27 Precast Concrete Products Committee was actively working on several new stormwater standards specific to hydrodynamic separators (HDS), which are often housed in concrete structures.  However, with the growing breadth of different types of SCMs available that extend well beyond concrete products, and a clear need for several new standards to bring consistency to the evaluation of SCM effectiveness, there was widespread consensus that a standalone committee was warranted.  

In addition to having a dedicated focus on SCM issues and standard development, another expected benefit of having a standalone committee is a much larger pool of stakeholders to participate in the standard development process.  E64 hopes to have participation from a broad range of stormwater professionals, including SCM manufacturers, academia, engineering/consulting professionals, regulators/program managers, laboratory operators/researchers, and other professionals with a vested interest in SCMs and relevant expertise to contribute.  Ultimately, a diverse and deep pool of participants will lead to much stronger standards than drawing from a subset of SCM/stormwater professionals would likely yield.  

Another program currently getting underway that’s worth mentioning, given the synergy with the formation of ASTM E64, is the national SCM verification program known as Stormwater Testing and Evaluation for Products and Practices (STEPP).  The STEPP program has recently found a new home under the umbrella of the National Municipal Stormwater Alliance2 (NMSA). It has also secured the funding needed to move the program forward in 2021!  The STEPP program intends to serve as a credible source of SCM performance verification based on testing under nationally accepted standards.  Before the formation of E64, STEPP was already collaborating with ASTM to develop standards based on the New Jersey Department of Environmental Protection’s laboratory protocols for HDS and Filtration SCMs3 and the Washington State Department of Ecology’s Technology Acceptance Protocol-Ecology (TAPE) field evaluation program4.  Work was already underway to develop HDS standards from the NJDEP protocol under C27, and this effort is now being transferred to E64.  Once complete, E64 will continue work on a variety of additional standards for evaluating filtration systems, trash and debris removal, and field monitoring that will be applicable to the STEPP program moving forward.  

Given the wide variety of SCMs now available, varying performance expectations, the current patchwork of protocols and methodologies used to evaluate performance, and the growing complexity of stormwater regulations, the need for robust and credible standards for SCM evaluation and deployment has never been greater.  The standards produced by E64 will undoubtedly be an asset for all of those involved in stormwater management.  Robust, credible standards will increase knowledge of SCM performance, improve comparability of different types of SCMs, increase the credibility of SCM performance claims, and streamline vetting and acceptance of SCMs by the regulatory community.  Paired with the STEPP National Verification program, ASTM standards for SCMs will also help create predictability and a pathway for acceptance for SCM manufacturers that should also drive future investment in SCM innovation.  Most importantly, strong SCM standards will ultimately be a net positive for water quality!


1. ASTM E64 Committee Homepage. Accessed online 6/11/2021.

2. National Municipal Stormwater Alliance STEPP Homepage.  Accessed online: 6/11/2021.

3. New Jersey Department of Environmental Protection Stormwater MTD Protocols and Guidance.  Accessed online 6/11/2021.

4. Washington State Dept. of Ecology Technology Acceptance Protocol- Ecology (TAPE) Program.  Accessed online: 6/11/2021.