The Land Down Under

May 29, 2018
Subsurface stormwater management system allows designers to maximize land above

Cultec, Inc.

P.O. Box 280 * 878 Federal Road * Brookfield, CT 06804

Phone 800/4-CULTEC

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 volume.

Ruiter wanted to minimize cost by reducing the amount of excavation required and complete the installation during the current construction season.

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.