When it rains, it pours – at least when it comes to stormwater. Just an inch of rain over an acre of land is equivalent to more than 27,000 gallons of water.
With no new water on Earth and freshwater making up less than three percent of global water reserves, stormwater runoff – created when rain falls on roads, rooftops and other paved surfaces that don’t let water soak into the ground – is an important step in the natural water cycle. However, untreated stormwater is the top cause of pollution and impairment for local streams, rivers and waterways in urban areas.
At Kennedy Space Center, galvanized metal roof structures are common at industrial facilities throughout the site. These roofs, which are typically zinc-coated iron or steel, can cause elevated zinc levels in stormwater runoff – impacting surface waters, harming fish and other aquatic life by binding to fish gills and causing suffocation.
But what if we showed you how Jacobs is helping Kennedy Space Center with a project involving installation of bio-filters at roof runoff outlets to mitigate potential negative impacts to surrounding water bodies and maintain a healthy and sustainable environment for animals, plant species and those who call the community home?
or more projected removal of total dissolved zinc from the stormwater runoff using the biofilter
gallons of water is generated from just one inch of rain over an acre of land
“Kennedy Space Center is completely surrounded by one of the most dynamic estuaries on the planet. To preserve the health of the lagoon, it is critical we prevent pollutants from being discharged into our watershed.”
Protecting local waterways with phyto-filtration
An important aspect of Kennedy Space Center’s environmental policy is a commitment to the health of the nearby Indian River and the wildlife it supports. Alongside Kennedy, Jacobs is implementing a pilot project at a structure near the launch pads. The aim of the project is to specifically target and reduce the zinc-loading of stormwater runoff being discharged to grade/surface waters from galvanized metal roof structures at the center.
Concentrations of total zinc in galvanized roof runoff can range from approximately 1,000 μg/L to more than 12,000 μg/L. Levels as low as 100-250 μg/L of dissolved zinc in runoff entering surface waters can result in harmful effects, inhibiting growth and survival.
At the project site, using a large plastic IBC tote, drain rock, screening, pea gravel and an underdrain piping system, our team constructed the biofilter. Then, we filled the top of the container using a sand filter, and a sand and compost layer. Lastly, we added plantings of rushes and sedges, along with bark mulch and large cobbles that form a splash pad.
The biofilter was placed under a roof downspout, directing stormwater runoff into the unit. Through the process of phyto-filtration as much as 90-95 percent of the total dissolved zinc is removed from the stormwater runoff. The water can then be discharged to grade with significantly reduced zinc concentrations.
Taking it to the next level
By limiting zinc concentrations in stormwater runoff and subsequently surrounding surface waterbodies including both the Indian and Banana Rivers, Kennedy Space Center continues and furthers its commitment to maintaining not only a healthy and sustainable environment for humans and other terrestrial fauna, but all biota; including aquatic plant and animal species. This furthers Kennedy’s existing sustainability outlook and serves to promote the center and its associated environmental policies as a model to industry, agency and corporate entities.
Following these initial successes, Phase III of the project assessment will include performing monthly stormwater sample collection/analysis, compiling data to determine Zinc (mg/L) reduction(s) in stormwater and extrapolate trend(s) and providing data for NASA for a six-month period to inform recommendations for a program expansion.
The possible expansion could include:
- Configuring biofilter runoff catchment to collect water for use by Kennedy Space Center Garden Club.
- In addition to phyto-philic plant species, installing decorative plants to support Kennedy Space Center beautification initiative.
- Coordinate with Delaware North to install biofilter(s) at Kennedy Space Center Visitors Complex for outreach purposes.
- Adding installation of biofilters to specifications for new metal structures at Kennedy Space Center.