Laconia is a popular tourist destination with four nearby water bodies: Lake Winnipesaukee, Lake Winnisquam, Opechee Lake and Paugus Bay. When the Courtyard on Paugus Bay, a summer cottage and motel property began renovation, treating stormwater runoff became an integral part of the plan. Prior to the renovation project, untreated stormwater discharged directly into the bay, just one mile from the drinking water intake for the town.
The renovation included replacement of eight cottages as well as the creation of a 26-space parking lot. Although the planned site improvements and landscaping were extensive, only 50 percent of the 0.80-acre site would be paved. This small amount of impervious area meant that the project fell below the requirements for stormwater treatment under the New Hampshire Department of Environmental Services (NHDES). However, the Town of Laconia required runoff be treated from any construction site over 50,000 square feet that is adjacent to the waterway.
Because of space constraints on the site, which sloped down to the water’s edge, using a land-based system to treat stormwater was impossible. Project engineer, Peter Howard of Steven Smith and Associates, had specified the Vortechs System before, and thought it would be a great fit for the site. In addition, the NHDES recently granted the Vortechs the highest verification ranking in their Innovative Stormwater Treatment Technologies BMP Manual. Howard proposed the system to the city’s conservation commission and they were impressed with its proven performance.
A Vortechs model 2000 was installed to treat up to 2.6 cfs of flow. The system was placed about 40 feet from the shoreline to remove pollutants prior to discharging into the bay. The installation process was expedited due to the unique horizontal profile of the system. Its shallow profile decreased shoring and dewatering requirements in the high groundwater environment, saving both time and money.
The Vortechs stormwater treatment system works to protect the quality of the town’s water supply and the health of Paugus Bay.