The EPA: Leading Into A Rain Garden?

Newly-installed solar Panels on the White House are an obvious signal that this administration wants to lead by example. Conservatives will no doubt find ways to ridicule the panels, and liberals will praise them as a display to the world that we are a green nation. About one year ago, on Oct. 5, 2009, the President signed Executive Order (EO) 13514, “Federal Leadership in Environmental, Energy, and Economic Performance.” Like the white house solar panels, this EO also is intended to urge federal agencies to lead by example. It sets as policy that federal agencies shall “…conserve and protect water resources through efficiency, reuse, and storm water management.”

How far have we come… and how far are we likely to be able to go in achieving these goals?

For federal facilities, the EPA's green infrastructure solutions , biological systems and engineered systems include, but are not necessarily limited to:

• Rain gardens, bioretention, and infiltration planters
• Porous pavements
• Vegetated swales and bioswales
• Green roofs
• Trees and tree boxes
• Pocket wetlands
• Reforestation/revegetation
• Protection and enhancement of riparian buffers and floodplains
• Rainwater harvesting for use (e.g., irrigation, HVAC make‐up, non‐potable indoor uses)

For new facilities, these would be good moves. For many years, our design firm has been planning new developments with very low environmental impacts, using approaches that have been either volunteered by the developer or mandated by the local regulations. We accomplish low impact designs by reducing the infrastructure needed for new development, which reduces both economic and environmental impact. Land development can be more efficient, when designed properly, than conventional or Smart Growth design methods; it can allow lower development costs while still complying with EPA mandates. It can be done by harnessing new design methods made possible by the development of new technologies. While “green” brings an image to builders' minds of expensive, problematic development, being “green” can be less expensive if done right.

Speaking from my experience in designing 700 neighborhoods in 46 States (and 13 countries), all with innovative design methods, and building a Net-Zero home in 1983, as well as a dual-certified Green home in 2009, here's how I evaluate the likelihood of success of the current EPA options:

Rain gardens, bioretention, and infiltration planters: These organic methods are possibly the most economically viable, but they do come with constant maintenance costs that the building facility owner must be aware of. A bio-retention that is not designed properly or maintained constantly will quickly fail. Unlike concrete pipes and iron sewer grates along curbs which can be left alone for decades, an organic solution to storm water must be installed by an experienced expert with a proven track record, and maintained by personnel that know what they are doing. If built correctly and maintained constantly, this can be the lowest cost solution IF there is enough land area and proper topography (flow of the land) to design the system properly in the first place. Typically, these systems rely on surface flow with no curbing or special curbing to allow drainage off paved areas. On newly developed sites, this could mean a significant cost saving. On existing development, replacing curb may be expensive.

Porous pavements: Sounds simple – install a pavement that allows rain to flow through to the ground. The big problem and huge expense comes from making sure that the ground under the pavement also porous. In other words, if you were to remove an asphalt parking lot and replace it with porous asphalt, the environmental impact would not change. Why? Because under the original asphalt is likely a non-porous class 5 (or similar) base. In a genuinely porous paved surface, the storm water moving through the pavement must continue through the ground below. This means a base that allows storm water to be held and filtered slowly to the ground below, or directed elsewhere. Sounds expensive? You betcha! Two other major problems: heavy vehicles used at federal facilities could damage these systems, and, if the ground freezes, expansion could be a problem. Long term lifespan of porous pavements may be less than that of solid surfaces.

Vegetated swales and bioswales: See rain gardens, above.

Green roofs: Retrofit Green Roofs on to buildings not originally designed for them? Green roofs did not work well in 1983 when I built my Net-Zero home during the first (failed, somehow forgotten) green movement, so I’m not sure what has changed to make them feasible. Green roofs can absorb the sun's energy to solve the heat island problem of large facilities, but simply coating a dark roof with a light or white color solves the heat island problem with little expense.

Trees and tree boxes: Trees and tree boxes will have little impact on reducing storm water impacts. Of course there are other benefits for planting trees, so, while a good thing, this does little to comply with the mandate.

Pocket wetlands: See rain gardens, above.

Reforestation/revegetation: Assumes the federal facility has plenty of space to allow such a thing.

Protection and enhancement of riparian buffers and floodplains: Assumes there are riparian buffers and flood plains on the site, or adjacent to the site, that can be altered.

Rainwater harvesting for use (e.g., irrigation, HVAC make‐up, non‐potable indoor uses): Also a good solution when possible. For example, when 90% of the surface is paving and rooftop, the resulting storage of rainfall could be tremendous, depending upon where in the country the facilities are located, and ample to irrigate the remaining small surface.

Nobody is an expert on all issues, so there may be new factors that I’m not aware of that would make a method more feasible than what we have experienced.

What is completely missing from the EPA options here are ways to make an existing facility more efficient by removing excessive paved areas. When an existing facility was originally designed, was it efficient in the first place? Keep in mind that being efficient is not necessarily profitable. If the original consulting engineer and architectural firm fees were based upon a percentage of construction costs, then creating excessive construction costs meant larger fees. Paving contractors maximize profit by covering the most land possible with asphalt or concrete.

The EPA order can be an opportunity to help design solutions that are cost effective to comply with the mandate. For my firm, the mandate could leverage our low impact software system sales, a technology that can be used to reduce wasteful construction while in redevelopment, so we may directly benefit from this mandate. But before that can happen — and before we can know how successful the EPA directives will be — many questions remain to be answered.

Photo: Pigeons in front of the EPA building by benchilada

Rick Harrison is President of Rick Harrison Site Design Studio and Neighborhood Innovations, LLC. He is author of Prefurbia: Reinventing The Suburbs From Disdainable To Sustainable and creator of Performance Planning System. His websites are rhsdplanning.com and performanceplanningsystem.com.