RECENT ADVANCEMENTS in building materials and mechanical equipment have made it easier for transfer stations to be “green.” For example, projects such as the Puente Hills Materials Recovery Facility (MRF), Whittier, Calif., and the Phoenix North Transfer Station, Arizona, recently have incorporated sustainable and high-efficiency elements into their facilities. This not only is expected to help the facilities save on monthly utility use, but it also should increase marketability and monetary rewards.
What Does Green Mean?
The biggest challenge for transfer station owners and developers is defining what “green” means, taking into account public opinion and regulations. Generally, it means being environmentally responsible and can involve:
Products made with salvaged, recycled, or agricultural waste content;
Products that conserve natural resources;
Products that avoid toxic or other emissions;
Products that save energy or water;
Products that reduce environmental impacts during construction, demolition, or renovation; and
Products that contribute to a safe, healthy indoor environment.
Understanding green options is important for a waste facility owner as well as for the design/engineering firm. Technologies and techniques change quickly as governments adopt environmentally friendly requirements. So when budgeting for facility design, both the owner and designers should allocate a nominal percentage toward investigating green options. The most practical elements solid waste handling facilities can consider are renewable or energy conserving alternative building materials.
Many facility owners will incorporate educational or public displays into their designs, which present opportunities to implement green features. For instance, transfer stations that include galleries, educational centers, guided tours and conference centers can raise awareness of facility operations. The public relations aspect of the business can be positive — but if mishandled, can hurt a facility's long-term success. However, using salvaged, recycled or agricultural waste materials can add to a transfer station's image as a community showpiece.
Using salvaged materials is one of the most cost-effective methods of demonstrating a solid waste facility is green. The concept is straightforward: reuse a building product instead of manufacturing a new one from scratch. Used building products are not necessarily less sound or less safe. Salvaged materials such as framing lumber, plumbing fixtures, bricks, millwork and hardware (e.g. nuts and bolts) often can be obtained locally. In fact, a little research on salvaging can yield a surprising number of sources for high-profile green materials.
Increasingly, solid waste managers also are considering the advantages of other recycled materials, such as rubber tires, aluminum, glass and newspaper products, which can be reused in flooring, trim and fixtures. The costs of implementing recycled and salvaged materials should be weighed against the benefits.
To conserve natural resources, engineers and architects can build facilities yet minimize the quantity of necessary building materials. Or, they can incorporate durable, low-maintenance materials into their designs. Designers may stain concrete floors or use unfinished concrete to eliminate the need for carpet or tile, or even eliminate wasted square footage. Engineers also can select materials that require less maintenance, but last longer, to conserve building resources and save money in the long-term.
Most consulting architects and engineers automatically try to conserve resources in their designs, but only to a practical level. If an owner wants to take a more stringent tack, additional research may be required, which will have an associated cost. The desire for a green building should be balanced against the facility budget.
Toxics and Emissions
Many products already are required by local or national environmental legislation to help reduce or eliminate pollution and waste from operations. Some examples include using products that reduce or eliminate pesticide, or using alternatives to ozone-depleting products that could contribute to pollution.
An ambitious facility owner might decide to further eliminate waste by using a vegetated roofing system to reduce stormwater runoff and surface water pollution. This concept is popular in Europe and recently was considered at Arizona's Phoenix North Transfer Station.
A transfer station and MRF, the Phoenix facility hosts educational and tourism areas and has a projected throughput of about 3,400 tons per day (tpd). Although the owner eventually decided not to use vegetated roofing, he contracted an independent energy-conservation consultant to prioritize green measures. Some suggestions were using reclaimed water for irrigation, recycled content materials, re-used agricultural content, solar water heaters, photovoltaic powered systems and high-efficiency full-spectrum lighting. The project is currently in its final design stages.
To eliminate the effects of solid waste facilities on their surroundings, designers usually are limited to erosion control and foundation products that eliminate the need for excavation. These elements are more focused on renovation and demolition, rather than new construction.
Saving Energy and Water
In many cases, products that save energy and water are practical and required by law. Requirements vary, but more states are adopting individual requirements on heating, ventilating, air conditioning (HVAC) equipment, lighting wattage, hot water systems and indoor air quality. Engineers should be aware of how each state's requirements will affect building costs.
For instance, materials that reduce HVAC loads are ideal, but can be challenging for the architects and structural engineers to incorporate because they can create a structure that looks different instead of just having thicker insulation on a roof or wall. Local building codes usually will require a minimum insulating value for materials, but code officials may enforce more stringent standards.
To select appropriate HVAC equipment, designers can turn to guidelines from organizations such as the Atlanta-based American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Some states and codes require more efficient HVAC equipment, particularly as prices and availability for electric power fluctuate.
In Florida, designers must seek approval on energy conservation through the FlaCom software program. For most engineers, using the program represents a second HVAC system modeling because most consultants already design using their own modeling software. Double-modeling costs will need to be accounted for in a project budget.
California design professionals must follow code Title-24 energy-conservation requirements that affect contract documents, generating forms, architectural and electrical design requirement types, HVAC systems, water systems, electrical systems and architecture. Engineers should be aware of how this will affect a building's budget, employee training and required design time, and then keep facility owners apprised of the costs.
Healthy Indoor Environments
A healthy indoor environment will affect the facility's occupants. Low-emission paints and building products, mitigation equipment, health hazard detectors such as carbon monoxide (CO) detectors, and other indoor qir quality (IAQ) detectors contribute to a healthy environment. Daylighting, the concept of using natural daylight to brighten facilities, also can improve employees' health and productivity. Moreover, daylighting can improve life cycle cost, saving on facility maintenance costs on a square-foot basis; increase employee productivity; and reduce operating costs by saving electricity.
The Puente Hills MRF, which serves a large percentage of Los Angeles, uses daylighting and lighting systems with occupancy sensors to reduce its toll on the environment. The main processing building is approximately 210,000 square feet and is part of a campus containing six structures. The facility projects a throughput of 4,400 tpd.
Because the facility shares operations with the largest active landfill in the country, the facility is designed to be a showpiece with educational and touring features. Some green elements were automatically included to comply with California's Title-24. However, the facility also incorporates noncontinuous systems with set backs and efficient building construction. Reclaimed water was used throughout the facility for nondrinking fixtures and irrigation.
Rosemead, Calif.-based Southern Cal Edison's (SCE), “Savings By Design” energy conservation program provided Puente with another incentive to be energy efficient. SCE offers monetary rewards if the owner and design teams meet minimum energy conservation criteria. The Puente facility project is currently under construction.
Green Requires Greenbacks
Selecting energy-saving products may appear to be a no-brainer — but they can be accompanied by higher costs. Using renewable energy equipment or design elements, such as photovoltaic systems (solar power), solar water heaters, ground source heat pumps and wind turbines, requires significant initial capital. Most design engineers will incorporate water-saving plumbing fixtures into their designs, but water-saving design may increase the quantity of piping materials on a project.
Despite higher costs, green features have a high potential for savings. Some green features are expected to pay for themselves over 10 years, while others have a required payback of up to 50 years. Partnerships between private enterprises or public utilities also can help to incorporate energy-saving elements into a facility while controlling costs.
Owners considering green design should evaluate their options in all project stages — preplanning, schematics, final design and cost estimations — to achieve maximum “greenness” for their dollars. Once initial suggestions have been made, prioritization is key. No project can be 100 percent green — at least not affordably. But even with limited funding, an owner can make a solid waste facility a showpiece of green building design.
Ryan D. King is with HDR's Waste Facility Design Group in Omaha, Neb. A version of this article was presented at SWANA's WASTECON 2003 in St. Louis.
Many elements of sustainable design programs such as the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) and the U.S. Army Corps of Engineers' Sustainable Project Rating Tool (SPiRiT) can be implemented into the design of transfer stations and materials recovery facilities (MRFs). Aspects that can be considered for sustainable elements include site selection, water efficiency, energy and atmosphere, materials and resources, indoor environmental air quality, and alternative and innovative designs.
For example, the Vashon Transfer/Recycling Station, King County, Wash., originally was intended to be a LEED-certified facility. The program assigns a point system to certain types of green options, and has different award levels based on the total number of points demonstrated on a given project. Some points come from construction, while others come from efficient operations and business practices.
However, as the Vashon project progressed, it became apparent that the LEED program would be difficult to directly address in a solid waste facility because it was originally intended for commercial-type buildings. Nonetheless, many of the recommended LEED elements were used in the final facility design.
The technical specifications for the project implemented a comprehensive construction waste management plan, with an emphasis on minimizing waste generation and salvaging or recycling wherever possible. There were requirements for green earthwork materials such as recycled Portland cement concrete rubble. All steel content for the building was 100 percent recycled content, and recycled fly ash was used in concrete. Roof panels contained a minimum of 25 percent recycled content, and ceramic tiles on the project contained a minimum of 50 percent recycled content.
While the facility was successful in incorporating many green elements, engineers also learned that the level to which a facility design incorporates green design is ultimately driven by the client.
— Ryan King