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September 15, 2000
As architects, engineers and planners we can each do our part, through sustainable building practices, to reduce the impact of building on the environment. However, government agencies responsible for establishing environmental regulations have potentially an even greater overall impact.
The Pierce County Division of Environmental Services is one such agency. Its activities include wastewater management, solid waste, stormwater management, and water programs. Each of these departments plays a significant role in the environmental stewardship of Pierce County, establishing criteria for how sewer, water and solid waste are handled as the county grows.
The agency recently got a chance to practice what they preach in its own building project and the result will be a benchmark for sustainable design in this region. In 1992, the county acquired more than 700 acres of land from Lone Star Northwest for expansion of a wastewater treatment plant. This large site, known for decades as the Steilacoom Pit, has become the focal point of the county’s 930-acre Chambers Creek properties. Steilacoom-grade gravel, a standard for public works projects throughout Washington, was mined from this pit for more than 100 years, leaving the area barren. The property also contains the tidal estuary of Chambers Bay, the heavily treed Chambers Creek Canyon, two miles of Puget Sound frontage, miles of creek frontage, and a variety of county services and operations.
It is extraordinary to have such a large piece of property in one ownership in the heart of the county’s urban core. It is also an extraordinary challenge, for any landowner to “do the right thing” in redeveloping it.
In early 1995, Arai/Jackson Architects and Planners was hired to help develop a long-term master plan. Over the next 30 months, a 12-firm team worked with county managers and staff, other agencies, citizens' groups and organizations to develop the plan.
One of the core themes for the planning process was “Reclaim, Reuse and Recycle.” A leader in garbage and yard waste recycling programs, the division had been conducting experiments with biosolids, a byproduct of the wastewater treatment process, for use as a soil amendment in creating “manufactured soils” that could help in reclamation of mines. Another valuable byproduct is the treated wastewater itself, which can be used to provide irrigation and wildlife habitat enhancements.
This core environmental theme, coupled with the county’s commitment to creating public access to the properties and the innovative public involvement process, captured the public’s imagination and enthusiasm. The plan was approved in 1997, and has been recognized by national organizations for its innovative public involvement and planning process.
The Chambers Creek properties will eventually include a championship-level golf course, playfields and park lands (all built over manufactured soils irrigated with treated wastewater), a boat launch, environmental education center, arboretum, production nursery, beaches, docks, and miles of public trails and pathways. These public areas will be partnered with government functions such as the wastewater treatment plant, administrative offices and maintenance services. The full plan can be viewed on the Internet at: http://www.co.pierce.wa.us/CCPMSP
The first county building on the site will be a 50,000-square-foot structure to house the Environmental Services Division offices, being designed by The Miller/Hull Partnership in collaboration with Arai Jackson. This building and its site improvements will set the standard for future development throughout the 928 acres.
The building concept grew out of several green building principles:
The building footprint has been kept narrow, allowing all workstations to be located within 10 meters of exterior glazing, per the “European model.” With the addition of skylights, every desk will get natural light. The building orientation is north-south, not ideal from a green building standpoint, but overhangs and sunscreens provide shading which enhances the architecture while preserving views of the Sound and Mount Rainier.
Offices will be situated mostly in systems furniture, with a small number of enclosed offices, workrooms and conference rooms. To preserve views these “solid blocks” were arranged in the east-west direction and staggered north to south. Electronic controls will turn off rows of lights, depending on natural light levels.
These blocks helped accomplish the second major principle -- integrating engineering -- by providing “chimneys” of open space, along the south side of each block and continuing up through the roof, terminating in a skylit box. These chimneys remove hot air from the building by natural convection.
Air will be supplied through a raised-floor system, one of this region’s first installations in a publicly owned facility. Although the raised-floor system is more expensive than traditional overhead ductwork, a life cycle cost analysis has proven that it will pay for itself in energy savings over an estimated five years. It also allows flexibility for workstation changes, with the entire floor system acting as an air supply plenum and exhaust being accommodated in the blocks.
Improved indoor air quality also played a role in the decision to go with this system. At night, cool outside air will be circulated through the raised floor system, cooling the thermal mass of the concrete structure, dropping its temperature by several degrees. Throughout the work day, as the space heats up, the cooled thermal mass will allow the air conditioning cycle to be delayed. In the summer months a 20-foot roof overhang shades the western windows until approximately 3 p.m. Low casework along the west window wall provides additional shade until 5 p.m., after the typical workday.
True green buildings require collaboration between architects and engineers. The mechanical engineer, AE Associates, was involved from the beginning of concept development, and was instrumental in reaching the ultimate design solution. Daylight studies by Joel Loveland of the Lighting Lab were vital in the approach to shading and daylighting.
The combination of thermal mass, overhangs and sunscreens resulted in a reduction in design cooling load from 150 tons to 90 tons over a conventionally designed facility. This will save the county in first costs, energy costs and maintenance costs. Also, a 63-degree supply air system allows for greater airside economizer usage, providing additional energy savings and prolonging the life of the refrigeration equipment.
The third major green building principle is what we refer to as the “human factor.” Fresh air, control over one’s environment, a connection to the outdoors, and color and patterns are essential to the well-being of the building occupants. Six interior planters have been placed below the skylit boxes of the office blocks, with room for interior planting to penetrate through the second floor. Operable windows are provided throughout, with HVAC controls connected to the building communications system, giving each occupant a signal when outdoor conditions are acceptable to allow the windows to be opened. Such features enhance productivity, reduce absenteeism and instill a sense of satisfaction among occupants. Major corporations such as Herman Miller, The Gap, Patagonia and others have reinforced this by adopting these ideas for their own buildings.
Finally, building materials have been carefully chosen. From an abundance of recycled-content materials to hardwoods from certified forests, nearly all of the building materials' environmental qualities have been questioned during the design process.
Site improvements follow green building principles as well, using technologies such as biofiltration swales to treat stormwater, indigenous landscaping and porous paving.
Where this project stands out from others is in the way these design features are presented to the public. With the division in the business of managing water quality, these features are used in ways that can easily be demonstrated.
One such demonstration area will be the Stormwater Plaza, developed by SvR Engineering and Bruce Dees & Associates. Stormwater runoff from the site will be collected for initial treatment. At the plaza, stormwater will be diverted through three treatment methods including two types of bio-filtration swales and a catchbasin outfitted with various filter types. It is hoped that this will be used by local students and water quality professionals to monitor how each of these methods works, side by side.
The north end of the building contains a large meeting facility, complete with a catering kitchen, that will be available for rent by the public. Outside this room and the main lobby is a large covered interpretive area with a view into the old gravel pit. Changeable interpretive panels will be provided by Aldrich Pears Associates, an interpretive design firm, to show what the pit used to look like and how it has changed over the years.
As part of the interpretive area, Bruce Dees’ office has designed a landscaped area which uses rain runoff from the roof as a feature. The water will be collected into a large scupper, dumping into a collection basin and then into a variety of treatment steps, all open for public view. A trail system, including a raised boardwalk over the treatment pond will tie into a trail system linking this end of the building to a future environmental education center, with demonstration gardens along the way where manufactured soils will be tested in various applications.
Along the trail system, several types of porous paving are used, each with signage explaining what it is. Unfortunately the higher cost of these products prohibited us from doing it throughout, but hopefully as demand increases the costs will become more competitive.
Starting with Pierce County’s vision, the creative master plan for its development and this first building project, the Chambers Creek Property has the potential to set a design standard for green building principles in this region for years to come.