Stormwater management is a significant green/sustainable construction issue and one can obtain LEED points for implementing it.
That was not the case only 15 years ago, however, when stormwater management was not at the top of the list for consideration when it came to new construction projects.
“No one really talked about 'green' then,” said Gregory Yazhbin, plant manager at Rinker Materials in Westfield, MA. “The rules were not that strict.”
Today, effective stormwater management has become one of the most critical issues of water resources management. Stormwater runoff now accounts for 80 percent of water pollution in North America, and governments are responding with demanding regulations to protect our water resources.
When it rains, oil, sediment and other contaminants are washed from paved surfaces directly into our storm drains and waterways. When stormwater policy experts, environmental scientists and the design community discuss stormwater quality and runoff issues, the one fact they all agree upon is that particle size matters.
Rinker Materials produces a product known as the Stormceptor that works by removing oil and sediment from stormwater during wet weather conditions. The unit slows incoming stormwater to create a non-turbulent treatment environment – allowing free oils and debris to rise and sediment to settle even during the most extreme rainfall.
On a recent project, Rinker supplied the Stormceptor 450 for installation by Forish Construction of Westfield at the Westfield Technology Center. The city of Westfield was upgrading the center on Apremont Way and needed stormwater management to control runoff from the parking lot.
Excavation of the site was limited to “no more than excavation for a typical manhole,” said Jim Lyons of Rinker. “The process takes two to six hours depending on site conditions. By site conditions I mean easy conditions like sand or harder conditions like ledge or high water table.”
Lyons said the Stormceptor is part of the drainage system and each year during routine maintenance, the pollutants are removed by a vacuum through a manhole cover.
“We go in and inspect the inside of the structure and remove the pollutants, and they are disposed of according to local and state regulations. We supplied the Stormceptor unit to the developer during the construction phase so that the project site would meet the current stormwater regulations as issued not only by the MADEP but also national standards known as NPDES (National Pollutant Discharge Elimination System),” said Lyons. “In essence, the proponent of any construction project must take measures to improve the overall water quality that will ultimately flow from their property – not only during construction but post-construction as well. When you disturb an area of land for construction purposes you need to have some kind of stormwater structure on the site. Engineers are familiar with what they need to design to get a certain amount of water quality.”
The Stormceptor system treats a minimum of 75 to 90 percent of the annual runoff volume and is capable of removing 50 to 80 percent of the total suspended sediment load as well as more than 90 percent of the floatable free oil.
The separator in the unit is capable of trapping silt- and clay-size particles as well as large particles. The unit is installed underground as part of the storm sewer system and must be structurally designed for (HS-20min.) traffic loading at the surface with the storage in the separator vertically oriented. The separator should be maintained from the surface via one access point.
The Stormceptor units are designed to remove a wide range of particle sizes (from 20 microns to 2,000 microns) as well as free oils, heavy metals and nutrients that attach to the fine sediment. The units can also be designed to remove a specific particle size distribution.
The manufacturing of the units is not a concept new to the Westfield plant that has been manufacturing here since 1959. The company has roots dating back to 1923 as one of the largest producers of underground storm drain products in New England.
Stormwater management products are used in most cities and towns throughout New England. The Stormceptor product was used on the Big Dig in Boston as well as state, city and private residential projects. The product can be found anywhere from single loading docks to 60-acre border transfer stations. The units are also ideal for parking lots, roadways, manufacturing and industrial projects, phase one and two compliance issues, spills capture, and pre-treatment services.