Design-Build Contract Risk Allocation - Design-Build for Water and Wastewater Projects - page 120

members were required to have a positive history of formal and informal partnering
with owners in the Rocky Mountain region.
The District used the Design-Build Institute of America's (DBIA) Standard
Form of Agreement Between Owner and Design-Builder, Cost Plus Fee With
a Guaranteed Maximum Price with Option for Shared Savings. The principle of
shared savings provided an equitable approach to sharing the risks and rewards of
a construction project by forming a partnership to promote teamwork and coopera-
tion by all parties. The team worked together and enthusiastically embraced each
other's input, commitment, dedication, expertise, and experience.
Lessons Learned
This project experienced and overcame several challenges. Although Fairplay is only
90 mi (14.5 km) from Denver, the location can be a challenge to reach during winter
months. Additional challenges required that the new treatment facility be able to
operate in extremely cold temperatures, be completely enclosed, and be able to run
unattended for extended periods of time. A part-time operator would be employed
to visit the facility each day; however, winter storms could eliminate access to the
facility. As a further challenge, heavy construction is practically impossible from
December to May. The facility needed to be constructed in a single short construc-
tion season, with a single mobilization to the site.
Due to potential inclement weather, a major challenge was to “close in” the
process structure to allow work to continue in any weather. As such, common-wall
concept was employed to allow accelerated construction. A single floor slab makes
up the entire foundation of the facility while four vertical walls surround the below-
grade process equipment, clarifiers, and process basins. The common-wall design
allowed for a minimum of slab pours. This design shortened the schedule, reduced
material quantities, and reduced overall cost. All internal yard piping was eliminated
other than a clarifier bypass line on the west side of the structure. Once wastewater
enters the square process structure, it does not leave until it has received prelimi-
nary treatment, secondary treatment, and disinfection. The single structure concept
has its own challenges. For instance, the headworks area (i.e., preliminary treatment
stage) has a different hazard classification compared with the rest of the facility. The
entire headworks area is physically isolated from the rest of the facility and is nega-
tively pressurized in relation to the adjacent interior spaces.
The result of this DB project is a facility completed in one construction season
that treats wastewater to quality levels beyond the requirement of the District's cur-
rent permit limits. Simplicity of the design and the treatment system allows for mini-
mal operational requirements.
Success Outcomes
The design-builder met the contracted substantial completion date of Aug. 19, 2009,
with a perfect safety record (i.e., zero recordable incidents, zero cases with days away
from work, zero cases with job transfer or restriction, and zero fatalities). The facil-
ity came online November 19, 2008, and within a month, the facility was meeting