The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the ...
Subsurface stormwater management system allows designers to maximize land above
P.O. Box 280 * 878 Federal Road * Brookfield, CT
When the state of Michigan’s Holland Community
Hospital wanted to add another parking lot to its facility, they had to meet
the city’s stormwater management regulations requiring a retention system
with discharge by infiltration.
As land development continues and more surface area is paved
over, there is less surface area for natural groundwater recharge to take
place. In addition, increased stormwater runoff from impervious surfaces
carries pollutants into local watercourses. Engineers are continually faced
with reducing or attaining zero increase in runoff from pre- to
post-development when designing a stormwater system.
In the case of the Holland Community Hospital, a surface
pond was not an option due to limited space. The engineering firm of Fishbeck, Thompson,
Carr & Huber opted for a Cultec, Inc., subsurface stormwater management
system for this project.
Going underground eliminated the maintenance and liability
associated with ponds and allowed designers to maximize valuable land above for
paved parking, landscaping, etc.
According to the company, Cultec is the only plastic chamber
manufacturer that offers a complete stormwater management plan consisting of
filtration, conveyance, storage and infiltration within its own product line.
Fishbeck, Thompson, Carr & Huber Senior Engineer, Ken
Ruiter, P.E., liked the company’s Recharger chambers’ structural
component with the repeating, fully formed end walls and the HVLV (high-volume,
low-velocity) Header System for the Holland Community Hospital project. According
to the company, the Recharger chambers have an open bottom and perforated
sidewalls for maximum infiltration capability and groundwater recharge. The
support panel helps to retain structural integrity and prevent the unit from
deforming under applied loads.
“It was important that the system have the structural
integrity to support the parking lot” Ruiter stated.
Another concern was preventing fines from getting into the
stone voids. The engineering firm specified Stormfilter, a secondary inline filter
system that removes many of the smaller particles not eliminated during the
pretreatment by conventional structures.
The Holland Community Hospital project used the HVLV Header
System, two Stormfilters and 195 Recharger 330HD chambers with 14,000 cu ft of
Ruiter wanted to minimize cost by reducing the amount of
excavation required and complete the installation during the current
The contractor for the job, Dan Hoe Excavating, Inc.,
installed the stormwater management system utilizing the chambers’ unique
overlapping rib connection.
Project Manager Rich Maike said this was his first time
working with Cultec chambers and the job went smoothly. According to Maike, the
units were installed in just one morning.