The initial wave of manufactured treatment devices (MTDs) were generally simpler than options available today. With few exceptions, early MTDs were comprised predominantly of swirl/vortex and other types of gravity separators that targeted solids and floating pollutants. State and local stormwater programs were in their infancy and were predominantly focused on reducing suspended solids loads. Our knowledge of particle size distributions and other common pollutants carried by stormwater paled in comparison to what we know today. MTD testing protocols were non-existent leaving early MTD providers to devise their own and make their case for acceptance. Regulators recognizing the need for underground solutions, especially in urban areas, implemented crude MTD performance criteria typically rooted in demonstrating removal of coarse solids in the laboratory.
Since the Environmental Protection Agency, and in turn state and local regulators, have gone all in on green infrastructure (GI) and low impact development (LID) concepts a seemingly regrettable consequence has emerged. Topics specific to the broader adoption and implementation of GI have monopolized our collective dialog on stormwater management of late. The predominantly positive press and barrage of GI heavy conference agendas seemingly suggest that if we apply GI far and wide then water quality impairments caused by urban runoff will soon be a thing of the past. GI provides stormwater practitioners with invaluable tools to aid in the stormwater fight, but many site specific challenges can’t be surmounted with GI solutions alone. To that end, should we be concerned that overemphasis on GI is discouraging innovation?
Drafting stormwater regulations that are clear, comprehensive and effective is crucial to protecting and preserving receiving waters. The Clean Water Act has yielded a wide spectrum of local stormwater regulations and policies, but many leave something to be desired when it comes to actually mitigating the impacts of urban runoff. It has been our experience that many local regulations are missing core components that are invaluable in achieving our ultimate goal.
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