Design manager Scott Trusler
is among the first to admit that designing a water treatment
facility to LEEDTM certification in one of the greenest cities
in the world is no easy undertaking. But thats exactly
what CH2M HILL Constructors, Inc., Bellevue, WA, set out to
do when it signed a contract with the City of Seattle in April
2001 to design and build the Cedar Treatment Facilities, Operations
Back at the proposal phase, we decided to go down a
path of least impact, including environmental stewardship
for both owner and company, Trusler explains. That can
prove to be a daunting task in and of itself. However, CH2M
faces the additional challenge of trying to reach LEED certification
on a fixed budget.
Six Submissions to the annual "What Makes It Green?"
What weve had to do is blend together the business
reality of designing and constructing with a fixed construction
price along with the introduction of sufficient points for LEED
certification, says Trusler. Although CH2M does have an incentive
payment to work toward if the project achieves gold certification
(silver is required for contractual compliance), its
been interesting from that standpoint because its been a more
rigorous process, he says.
With the City of Seattle being out in the forefront of green initiatives,
certain features of the project come with very high standards. For
example, the construction waste management plan for the project
has an ambitious goal of diverting 75 percent of construction waste
material from the landfill by means such as recycling wood forms,
waste material and packing materials. Additionally, a dedicated
area for recycling within the building will be part of an ongoing
recycling plan for the facility after occupancy.
Further, a goal for strict construction limits has been set that
allow site disturbance only slightly beyond the building footprint
and parking lot. Those areas that are being disturbed during construction
will be restored, and the trees on site will also be preserved where
practical. A soil and erosion control plan will stabilize the area
during construction through seeding, silt fencing and bioswales,
and water runoff will be addressed with permanent stormwater detention
and treatment and pervious paving.
The structure itself, which will be staffed 24 hours per day with
treatment plant operators, facilitates natural heating and ventilation
through strategically placed operable glazing, passive solar shading,
sloping roofs and a large thermal mass. High reflectance metal roofing
will also be used on a portion of the roof to reduce heat island
effects in summer, and clerestories automatically open to purge
warm air. A heat recovery duct on the south end of the building
captures radiant heat, which is then used to warm other parts of
the building interior.
Daylighting is provided throughout the building with windows and
clerestories made with high performance low-e glazing. High performance
lighting, HVAC systems and Energy Star-rated appliances further
reduce energy demands in this efficient structure. Building commissioning
will also help maximize energy efficiency, as well as provide cost
savings over the long-term life of the building.
At least 25 percent of the materials specified for the project have
recycled content, with a goal of achieving 50 percent for both exterior
and interior work. Materials include recycled plastic toilet partitions,
gypsum wall board, concrete, rebar, carpet and ceiling tiles. Goals
such as these can be difficult to achieve due to construction phase
realities related to material availability, cost premiums associated
with limited competition and other factors. Therefore, the LEED
certification is not heavily reliant on achieving these goals.
In addition, a primary goal is to have 20-40 percent of the materials
manufactured and harvested locally, including the CMU, certified
wood, metal doors and windows and concrete. Many of the materials
are also made from renewable resources such as cork and rubber flooring,
landscape mulch, cellulose insulation and straw and wheatboard for
walls and casework.
The design team worked to enhance green design in every facet of
the building inside and out. But even in the details, the overall
goal of the facility was kept in mind.
This building is a small piece of a much bigger project,
Trusler says. The purpose of the much bigger project is making
180 million gallons of high quality drinking water per day. Thats
the core objective of the facility.