Case Study 3: Virtua Voorhees Hospital

  • The Virtua Voorhees Hospital viewed across the stormwater wetland. Photo Credit: Dewberry

Project Overview   |  Design Summary |  Decision-Making    |   Challenges   |   Maintenance


Development Type: Healthcare Campus
Location: 100 Bowman Drive, Voorhees, Camden County, NJ 08043
Developer/Design Team: Virtua Health; Dewberry; HGA Architects & Engineers
Sewer Type: Separate Sanitary and Storm Sewer
Completion Date: May 2011


Project Overview:

Ten years in the making, Virtua Voorhees is a 120 acre healthcare campus development constructed on a greenfield site along NJ State Highway Route 73 in Voorhees Township, Camden County, NJ. The site was assembled from a number of single family, commercial and vacant lots. The project consists of a 386 bed inpatient acute care hospital and 300,000 sf health and wellness center. The initial development on the campus was built by a partnership between Virtua Health and a private healthcare real estate developer. Virtua Voorhees achieved Leadership in Energy and Environmental Design (LEED) Silver certification.

The Virtua Voorhees campus was envisioned as a state of the art healthcare development that promotes a sense of healing from the moment one arrives on the campus. This vision is supported by the presence of many green infrastructure practices throughout the development. From preservation of onsite freshwater wetlands, natural viewsheds and lush native landscape treatments that, in some cases, also manage stormwater; to site amenities such as walking trails and bike lanes, the campus allows patients, visitors, staff and the community to experience the beauty of the setting while providing the highest level of healthcare and healing consistent with Virtua’s mission to ‘be well, get well and stay well’.

The 120 acre site lies along Route 73 in a Major Business zone district. As part of the project approval process, a General Development Plan that lays out the long term vision for the eventual buildout of the campus was developed and approved by Voorhees Township. The surrounding areas include residential neighborhoods, retail and commercial development along the state highway, a golf course and public park. The site is served by a NJ Transit bus route with stops provided onsite


Design Summary:

The design team incorporated green stormwater management techniques that required additional design and planning, but which nonetheless achieved compounded improvements to site water quality and aesthetics. Green infrastructure provides multiple benefits to Virtua Health, its employees and the patients that visit the campus. The green infrastructure helped Virtua Health obtain NJ DEP and local regulatory approval, offers a beautiful place to work and visit, and provides multiple environmental benefits as well, including wildlife habitat and stormwater quality treatment.

By incorporating green stormwater infrastructure, the project also provides benefits to the local municipality by improving the water quality of stormwater leaving the site, reducing downstream flooding, and replenishing groundwater aquifers. The campus is a testament to the fact that implementation of a sustainable approach to site development and stormwater management using green infrastructure is not only feasible but beneficial from both an environmental and economic standpoint for both the property owner and the community.

The well-integrated green infrastructure practices include a mixture of structural and nonstructural stormwater management techniques including surface and subsurface groundwater recharge basins, extended detention basins, wet ponds, constructed stormwater wetlands, vegetated swales and rain gardens. Green roof areas are also incorporated into the building design to enhance “look down” views, provide passive cooling and reduce roof runoff volumes. All site runoff is eventually either recharged or discharged to surface waterways at below pre-development rates.

  • Groundwater recharge basins provide water quality treatment, runoff rate reduction and groundwater recharge for a majority of the drainage areas at the south end of the campus. Minimal curbing on roadways and parking lots promote sheet flow and shallow flow into linear roadside swales that convey runoff into the basins. By minimizing the amount of curbing through sheet flow and by using surface swales rather than underground piping, construction costs were reduced. Through this green infrastructure approach, the first flush of runoff has greater opportunity to be completely retained onsite and infiltrated to groundwater.
  • Subsurface infiltration was incorporated as two large fields of High-Density Polyethylene (HDPE) arched chambers installed beneath parking areas comprise a major subsurface infiltration system. These chambers collect rooftop runoff and directly recharge ground water without the need for water quality treatment.
  • A constructed stormwater wetland was an ideal GI practice for a poorly drained area with a high ground water table located near the center of the development and flanked by two preserved wetlands. A stormwater landscape of microponds, high and low marshes and permanent pools remove a large portion of sediment carried in runoff to achieve a TSS removal rate of 90%. The constructed stormwater wetland offered an opportunity to make the most of difficult site conditions and demonstrate compliance with regulatory requirements. A meandering walkway weaves through the complex and connects the wetland to other traditional stormwater features on site, creating a holistic and connected environment.
  • Vegetated swales are located along the perimeter of much of the surface parking and campus loop roadway areas. By directly capturing runoff from these large impervious areas, the swales eliminate the need for traditional piped infrastructure to remove runoff, which reduced construction costs. Micro-scale design elements such as check dams and intermittently spaced inlets along the channels promote infiltration, control stormwater flow and prevent ponded water.
  • Three large rain gardens sited at the north end of the campus collect runoff from the large employee parking lot while lush planting of native trees, shrubs and colorful perennials in the rain gardens serve as an attractive visual buffer along the north entry drive.
  • Green roofs were strategically placed at lower roof levels to be visible from patient rooms which create soothing ‘look down’ views which would otherwise have barren views of traditional roofscape.

Decision-Making:

The wide array of carefully chosen green infrastructure practices resulted in many benefits including reduced construction costs, attractive views, and expedited compliance with regulatory requirements. The decisions that were made to incorporate green infrastructure are summarized below.

  • Virtua’s primary objective for this project was to create a cutting edge, high quality environment in which to deliver exceptional health care services. In light of this primary objective, construction cost decisions were carefully weighed against the health system mission’s statement. Accordingly, the design team elected to incorporate extensive green infrastructure practices as an opportunity to satisfy multiple needs: enhanced aesthetics, reduced construction and/or operating costs, promote a more natural landscape and achieve expedited regulatory compliance.
  • The decision to eliminate curbing and traditional stormdrain piping where possible resulted in hundreds of thousands of dollars in savings.
  • The project development team decided at the beginning of the project to incorporate a site sensitive stormwater design that responds to local soils, wetlands, woodlands and topographic conditions. The strategy used to meet the goal entailed a wide range of green stormwater practices to meet the regulatory and functional requirements of the project.
  • Green roofs were chosen as a cost-effective way to manage stormwater without the need for additional infrastructure. The minimal added weight was easily accommodated without significant change to the structural design.
  • The design team’s decision to incorporate green infrastructure and their close working relationship with NJ regulatory agencies (NJ DEP, NJ DOT) during the permitting process helped to meet the stormwater management goals of all parties without delay.

Challenges:

  • For a project of this scale and magnitude, the design team had to negotiate a complex regulatory environment requiring adherence to multiple agency requirements. By incorporating green stormwater infrastructure, this process did not result in permitting and approval delays.
  • Difficult site constraints and development program needs made for a challenging design effort. Green infrastructure helped to overcome this challenge. Implementing distributed green infrastructure practices to manage stormwater instead of more traditional detention storage areas in underground facilities resulted in a better design. While additional underground facilities would have increased valuable area for parking, the need for expensive pretreatment systems such as manufactured treatment devices made it more cost effective to comply with water quality permitting requirements using green infrastructure.
  • Incorporating green infrastructure into the construction sequence without negatively impacting the facilities was a challenge. Temporary stormwater controls such as rock check dams, temporary sediment basins, silt fence, haybale barriers, and temporary curbing were implemented prior to installing the permanent green infrastructure facilities in order to avoid damage during mass grading, earthwork, and paving operations. By using temporary controls, the vegetation in the swales and rain gardens were installed later in the construction process so they were able to establish without the risk of sedimentation and damage from heavy equipment.

Maintenance Overview:

  • Maintenance of the green infrastructure and stormwater management measures is undertaken by Virtua’s facility management group with the assistance of contract service providers.
  • Maintenance for the green roofs is minimal and includes regular inspections to ensure the plant material is in good condition and an occasional watering during extended periods of hot, dry weather.
  • With extensive “no mow” meadow type landscaped areas, regular lawn mowing services are more limited than is required by traditional lawn areas.
  • Water quality treatment is provided with nonstructural measures so there is no need or cost for periodic removal of oils, trapped solids, and cartridge replacement as is the case with structural manufactured treatment devices.
  • The recharge basins, constructed wetlands, wet pond, and vegetated swales all require minimal annual maintenance at little cost other than would be required for any typical landscaping contract.

*Some of the stormwater management best practices used in this case study are not defined explicitly as green infrastructure by NJDEP.

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