Kure Beach Dune Infiltration System
The Kure Beach Dune Infiltration System (DIS) is a new and innovative sand filter Best Management Practice (BMP) designed to reduce flow volumes and bacteria concentrations discharged directly onto the beach or into the ocean
Currently in many coastal communities, untreated stormwater is discharged into recreational waters through stormwater beach outfalls. This discharge often contains high levels of fecal bacteria, known to cause various illnesses in humans. Due to the discharge of this bacteria into swimming waters, the NC Recreational Water Quality Program monitors nearly 240 beaches statewide, for fecal indicator bacteria levels. When the levels exceeded the state maximums, Swimming Advisories are issued and warning signs are placed near the sample area.
Therefore, in an effort to reduce the health risks, number of swimming advisories, and discharge, the NC DOT, Town of Kure Beach, and BAE Department at NC State are investigating the effectiveness of the DIS to treat bacteria laden stormwater. The DIS uses the existing sand dunes as a natural sand filter, allowing stormwater runoff to be directed underneath the dunes where it is filtered and then transported to the ocean through natural groundwater movement.
Two systems were constructed in 2006 and a third system in 2009. Monitoring at each site includes stormwater flow measurements, stormwater bacteria and nutrient testing, water table elevation recording, groundwater bacteria and nutrient monitoring, rainfall recording, and dune sand sampling for bacteria. The monitoring results from each system have been promising, with a 100% capture rating at Site L, 96% at Site M (meaning only 4% of the stormwater has bypassed the system in five years), and a 80% capture rating at Site K. In addition, bacteria levels in the groundwater have remained mostly below the state maximum for Tier I recreational waters. Natural dune hydrology has been maintained at each site, with the only observable impacts occuring during and shortly after infiltration events.
“Because we have installed several StormChamber systems, a lot of engineers have asked for advice on competing plastic chambers. We have always recommended the StormChambers. They far exceed the competition on cost and ease and speed of installation.”
“Much less expensive and much quicker and easier to install than the 64″ pipe originally speced for the project.”
“Significantly faster and easier to install than pipe. Significantly less staging room needed and a lot fewer trucks to receive and unload.” (The equivalent of 213 LF of pipe nest on one pallet, 1,913 LF on one truck.)
“We have installed several StormChamber systems because we find them to be a lot less expensive and quicker to install than the competing systems and we can install them in two layers on very confined sites.”
“We were surprised by the ease of use of the system and greatly appreciated support provided. We are already looking forward to building our next StormChamber project!”
The Loudon One project in Ashburn, VA
“I also like that it can be cleaned by air vacuuming via inspection /cleanout ports instead of using water. Anytime you have to clean something with water, then you have to have a truck that collects the water and the sediments in it. Depending on where you can dump that, it can get much more costly as opposed to going out with a vacuum truck.”
HUGO SIMS METAL RECYCLING FACILITY IN THE BRONX, NY
“The choice of StormChambers met the design requirements for strength in such a way that the chambers could be stacked three deep with 30 feet of cover, if needed. Strong enough to sustain the impact of 18-wheelers loaded with steel. They also were 30 percent more cost-effective than other options.”
Double-stacked system in Tukwilla, WA
“It was easy. There were no difficulties once the owner decided on the StormChamber system. The project is holding up to heavy traffic, pump tracks, and cranes.”
Charles-Lemoyne Hospital, Greenfield Park, Quebec
"We were amazed by the simplicity of this system and have appreciated the support from the Soleno team during the entire project. We are already looking forward to designing another project using the StormChamber!"