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Technology
Coastal Communities Turning to Vacuum Sewers
(designbuild.construction.com - May/June 2005 issue)
By Tom Nicholson
Teaming designers and builders in integrated
project delivery has streamlined work on numerous building
and road construction projects, saving time and money and
freeing owners from change orders and multiple contracts.
Now, design-build project delivery also is showing up on underground
pipe-laying projects where contractors work side-by-side with
designers in developing optimal plans before digging in.
That’s how things worked out over
the past two years on a sewer project in Ponte Vedra, Fla.,
where Jacksonville-based Callaway Contracting Inc. teamed
up with Coral Springs-based Eckler Engineering Inc. for a
$10-million design-build job commissioned by the Jacksonville
Electric Authority. The project involved construction of an
innovative Airvac vacuum sewer system in the 672-home Ponte
Vedra Beach subdivision, which previously had individual septic
tanks for each home. The work included burying 45,000 ft of
6 in., 8 in. and 10 in. PVC pipe, installing one valve pit
for every two homes and constructing a pump station with three
25-hp vacuum pumps capable of moving 450 cfm of wastewater.
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JEA merged with the Jacksonville Public
Works Dept. in 1997 and now operates JEA Sewer System, which
includes six regional wastewater treatment plants and 2,500
miles of collection lines. The state ordered JEA and St. Johns
County to install a sewer system at Ponte Vedra after the
state Dept. of Environmental Protection conducted tests in
nearby lagoons and found contamination from the subdivision’s
hundreds of septic tanks.
The high water table in the ocean-side
community compounded the pollution and also would have complicated
construction of a gravity sewer system, which would have required
deep trenches. "JEA’s typical method of sewer collection
has been traditional gravity," says JEA spokesman Greg
Corcoran. "After quite a bit of research, JEA became
convinced that vacuum sewer collection could provide an acceptable
alternative and, given the right conditions within a project
area, the use of vacuum could potentially be installed at
a cost savings over traditional gravity. Ponte Vedra provided
these favorable conditions so vacuum sewer became the system
of choice." Click here to view rendering
With cost savings in mind, JEA and county
officials opted to do the project under a design-build contract.
"JEA felt the design-build method of delivery was best
suited for this particular project [because] the vacuum sewer
technology was a new system for JEA and we felt the use of
a design-build firm would provide the expertise needed to
design and build [it]," Corcoran says. "The goal
was to create a concept of ‘total responsibility’
for the design-build team." JEA is a knowledgeable owner,
having previously used design-build on upgrades to wastewater
treatment plants and new chilled water plants and felt comfortable
applying it to a sewer grid.
Leading Edge
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| Vacuum
system uses smaller diameter, lightweight pipes and shallow
trenches. (Photo by Ed Stephenson) |
JEA published a request for qualifications
for the job in mid-2003, and after reviewing a pool of eight
respondents, short-listed three firms. Calloway got the nod,
despite its lack of experience with design-build or vacuum
sewer projects. It was a selection based largely on their
past working relationship with JEA. "We had done about
$50 million of work with JEA before, doing water lines and
pipe laying projects," says Callaway’s project manager
Stan Bates. "We had never done design-build before and
it was also the first time for JEA on a sewer project, so
this was a learning process for both of us."
Corcoran says respondents were evaluated
for qualifications in safety, project-related knowledge, record
of past performance, resources and financial responsibility.
"Although many exceptional teams responded to the RFQ,
JEA’s evaluation team felt Callaway Contracting’s
abilities gave them the edge over their competitors,"
he says.
With Callaway in the driver’s seat,
the next step was for it to choose a design firm as well as
determine which vacuum system would be best suited for the
job. "We talked to two vacuum sewer companies about their
product and also asked if they could recommend an engineer
for the job," says Bates. "In the end we felt Airvac
was the superior product."
Rochester, Ind.-based Airvac’s
prominence in the vacuum sewer field, and its comprehensive
support plan were big factors in the company’s favor.
Airvac provides clients with an onsite field representative
during construction who stays on location for the job’s
duration to assist contractors with the installation. The
company also offers a week-long training program as part of
its contract in which owners can send two representatives
to the company’s Rochester training facility. When possible,
...
(continued...)
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