Positive Benefits of Net Zero Innovation
An integrated design and construction approach delivers a first-of-its kind equipment wash facility.
By Richard Shelton, P.E., LEED AP BD+C, DBIA, M.SAME
Stormwater runoff is a leading source of water pollution in the United States. Congress enacted Section 438 of the Energy Independence and Security Act of 2007 to require federal agencies to reduce stormwater runoff from federal development projects to protect water resources. Moreover, Executive Order 13514 directs federal agencies to “lead by example” in addressing a range of environmental issues—including stormwater runoff.
In 2012, the Martinsburg, W.V., U.S. Department of Veterans Affairs Medical Center (Martinsburg VA Medical Center) began developing a Storm Water Management Program (SWMP), “Chesapeake Bay Protection and Restoration,” to comply with the federal guidelines. The program was designed to reduce the discharge of pollutants from this small municipal separate storm water system, satisfy water quality requirements of the Clean Water Act, and help protect the Chesapeake Bay watershed. The Martinsburg VA Medical Center storm water system drains into the 64.4-mi-long Opequon Creek, which is a tributary stream of the Potomac River and eventually Chesapeake Bay.
The medical center has numerous vehicles and equipment that require maintenance and cleaning, including fire trucks, police cars, fleet cars and vans, patient buses, dump trucks, and excavation and landscape-maintenance equipment. Previously, these all were washed with municipal, potable water in parking lots scattered across the campus. This led to contaminated wastewater entering untreated into VA’s campus stormwater system and ultimately into the Chesapeake.
ADDRESSING A NEED
The Martinsburg VA Medical Center wanted a means to wash all types of dirt and pollutants from a variety of vehicles and equipment, comply with the SWMP, and address local and state water quality requirements. At a minimum, the facility and pollution control system had to meet the requirements of the 2007 National Pollution Discharge Elimination System Water Pollution Control Permit for Vehicle Washing Establishments, West Virginia Department of Environmental Protection (DEP) Division of Water and Waste Management.
VA determined the primary performance requirement would be a dual-bay facility that could wash an average of six very large vehicles such as fire trucks and buses per day. VA conservatively assumed each vehicle would need on average, 50-gal of water for cleaning, which meant at least a 300-gal rainwater storage tank was needed. VA wanted firms proposing on the project to consider rainwater harvesting. Also, the medical center decided to take a “leadership role” as well and not discharge any contaminated wastewater into the storm water or sanitary sewer systems by treating it on site before release.
The West Virginia DEP permit specified a sedimentation tank be used prior to a filtration box, with only the size of the filtration material specified. The goal was to allow the wastewater to be safely discharged into the local watershed, which is located in a karst geologic area (bedrock in the area consists of porous limestone).
DECIDING ON DESIGN-BUILD
VA elected to solicit for an integrated design and construction solution, and ended up choosing design-build delivery. They also established additional performance requirements for the design-builder. The facility was to be cost effective to operate and maintain because of limited Operations and Maintenance budget dollars; it was to match the industrial architectural theme of that part of the campus; and it needed to offer year-round use. A combination of performance requirements and prescriptive specifications was part of VA’s acquisition strategy. The winning proposal was selected using a best value source selection process.
As with most VA projects less than $10 million, this solicitation was set aside for service-disabled, veteran-owned small businesses. Once Royce Construction Services was selected for discussions, the team presented, negotiated and was awarded a firm-fixed price design-build contract.
PURSUING NET ZERO
Royce Construction Services and partner Wiley|Wilson designed and constructed the Martinsburg VA Medical Center equipment wash facility to efficiently clean VA equipment with collected rainwater. During times of low rain, a municipal water connection can provide backup water. However, Royce Construction Services also designed and constructed the wastewater treatment process so that cleaned wastewater could be used. Since its opening in September 2012, the facility has never used backup potable, municipal water. It relies solely on rainwater and reused wastewater.
After washing equipment, the wastewater travels into a trench drain and filter basket, which collects small particles such as grass, gravel, pebbles and most sand. The wastewater then travels through a sedimentation tank, which removes most non-soluble particles with a specific gravity higher than water (sand, trace metals, silts), before then passing through the large filtration tank. Royce Construction Services designed and installed a large precast concrete tank. The tank was filled with the West Virginia DEP-required sized materials, though crushed limestone aggregates were chosen to assist in the filtration and cleaning process. The coarse limestone sand is anticipated to last eight to 10 years.
The wastewater then is filtered under high pressure through 5-micron replaceable cellulose filters. Finally, it is heated and sent to dual high pressure pumps, where biodegradable soap is added before it travels to the pressure wash wands in each bay.
The facility was designed to be extremely easy to use. Without any training, VA employees can turn on the system and wash equipment. The system incorporates weep features to ensure the stainless steel wash wands do not freeze, allowing year-round use. The structure also blends well with the surrounding industrial architectural theme. The project is now an integral part of the campus SWMP protecting the Opequon Creek and Chesapeake watershed.
Through many design and engineering specifications, enhanced value was brought to the project at no additional cost to VA:
- High-density, polyethylene rainwater storage tanks are relatively inexpensive so the size of the mechanical room was increased, double doors were added and a larger 1,000-gal rainwater storage tank was installed. This means, based on the original assumption, that VA can easily wash 20 large vehicles daily.
- The facility was relocated and its orientation changed to take advantage of a large warehouse adjacent to the site. The rainwater from the warehouse roof now is diverted to the rainwater storage tank.
- A downspout filter was added to the rainwater harvesting system. This system uses a natural cyclone effect to centrifugally accelerate particular matter (such as leaves, twigs, feathers and bird droppings) out of the rainwater prior to entering the rainwater tank. Less than 10 percent of the rainwater is lost, which is diverted directly to the bio-swales.
- A specialized rainwater-only filling device was installed in the rainwater storage tank that flushes the tank by displacing existing water. Since filtered wastewater is lighter, it is displaced first whenever fresh rainwater is collected.
- Timers shut down all systems if the facility is not used for five minutes.
- 5-micron cellulose filters and two UV disinfection lights were added to destroy microorganisms preventing the use of chlorine, iodine, or other chemicals that would be harmful to the watershed.
- Integrally colored concrete masonry unit (CMU) blocks were used for all walls to eliminate a future need to paint it.
Other sustainable features include recycled materials in the metal roof and precast concrete tanks; local materials such as the CMU blocks and cast-in-place concrete; water-efficient landscaping and groundwater recharge using bio-swales; energy efficient water heater and high-pressure cleaning system; and non- volatile organic compound adhesives, sealants and paints.
SUCCESSFUL AND SUSTAINABLE
The project was recently recognized by the Design Build Institute of America (DBIA) with both regional and national level awards. Royce Construction Services is the first service-disabled, veteran-owned small business ever to receive a DBIA award. The project also was nominated for a 2013 GreenGov Presidential Award.
The Martinsburg VA Medical Center’s equipment wash facility achieves net zero water use. It saves the government thousands of gallons of municipal water every month and protects several waterways, including the Potomac River and Chesapeake Bay. It is cost-effective, sustainable, and a first-of-its-kind—and it was built by a small business.