Pushing State-of-the-Art at Johns Creek

$137 Million Johns Creek Environmental Campus Could Be National Model

By Steve Setzer

The Johns Creek Environmental Campus in Roswell, Ga., won’t look or smell like a typical large-scale wastewater treatment plant. And if everything goes as planned, motorists passing by will think it’s some kind of college campus with a lake, brick-clad buildings and lush landscapes.

A design-build team led by Archer Western Contractors of Atlanta has passed the 50% completion mark on its $137 million, 15 MGD project in Fulton County. The facility will feature the largest application in the United States of a new breed of biomembrane reactor wastewater treatment plants – a technology that is becoming the standard for new and retrofitted treatment plants due to its efficiency and low cost relative to other treatment options.

The plant also will feature an above-ground environmental campus in a park-like setting designed to educate people on water and environmental issues.

If the remainder of the work goes as planned, the Johns Creek Environmental Campus, scheduled to go online in November 2009, will be a national example of how to successfully procure and deliver a major treatment plant in a crowded suburban environment.

Focused on the RFP

The Fulton County Department of Public Works’ RFP for the project included detailed performance specs, as well as extensive provisions for community relations to calm concerns from nearby neighborhoods.

advertisement

“The owners had a clear picture of what they wanted,” says Matt McCormack, project manager for Archer Western. The contractor teamed with design engineering firm Brown and Caldwell of Roswell.

The Archer Western team’s proposal was $20 million higher than the next bidder but prevailed based on overall responsiveness to the RFP, construction and design innovations and its planned approach to meeting the plant’s performance specifications, McCormack says.

Paul Williams, a procurement specialist with Fulton County, confirmed McCormack’s assertions, and said the RFP was a hybrid design/build approach.

“We defined certain base elements like noise abatement, odor control and architectural features,” as well as specification of the bioreactor membrane technology, he adds. Fulton County particularly liked Archer Western’s approach to phasing the work, as well as its design for the interpretive and educational components of the facility, Williams says.

Archer Western is self-performing roughly 70% of the work, with other large subcontracts consisting of an electrical contract with Excel Electrical of Atlanta and a $4.5 million landscaping contract with Valley Crest, also of Atlanta.

Community outreach was a key factor in the preconstruction phase and early stages of the work, says Simeone Solomero, construction manager for Fulton County. Brown and Caldwell built a detailed public Web site and provided monthly updates, along with postings from local media.

A series of public meetings were held, including several meetings early on with homeowners at a nearby neighborhood of multimillion dollar homes.

BMR Technology

General Electric’s ZeeWeed biomembrane reactor technology that’s being used on the Johns Creek project has been specified on plants totaling almost 100 MGD in north Georgia, according to GE spokesperson Anthony Kobilnyk.

The technology uses extremely fine fibers enclosed in membranes to filter the last stages of wastewater. Each membrane fiber has billions of microscopic pores that form a physical barrier to suspended solids and colloidal material in wastewater. A slight vacuum is used to create suction within the fiber that draws clean water to the inside, while blocking contaminants on the outside.

Bacteria, viruses and other pathogens are also prevented from passing through the membranes, according to GE. The result is near-drinking quality water that can be used for irrigation, groundwater recharge or process water, thus reducing demand for pure drinking water.

The membranes are housed in large cassettes that can easily be maintained and replaced as needed.

Other than Johns Creek, the most recent application in north Georgia was announced this spring for Gwinnett County, also located in suburban Atlanta. As part of a $250 million plant upgrade, the BMR technology will boost treatment capacity at Gwinnett’s Yellow River Water Reclamation Facility by 7.5 MGD to 22 MGD.

Construction Challenges

The project has not been without problems. The team struck water almost immediately after starting excavation of the deepest section of the headworks – 60 ft below grade for the main influent pumping system.

“It was almost like an old riverbed running through the excavation area,” McCormack says. The problem was contained using well points and pumps and did not seriously disrupt the schedule.

The next step involved large-scale excavation of the remainder of the below-grade process structures. Archer Western moved 200,000 cu yds of dirt, but planned the work so that the site was balanced and no excavation soil had to be removed from the site.

Archer Western chose to use precast structural elements instead of cast in place for the 90,000 sq ft of aboveground outbuildings – one of the elements cited by Fulton County as a schedule accelerator. This helped avoid production problems onsite and also allowed for staged delivery of structural shapes, McCormack says. While there have been some capacity issues with the precast subcontractor, ZMZ Precast of Atlanta, the overall schedule is still on target.

Managing Cost Escalation

The team also faced a sharp escalation in materials costs from the time the RFP was submitted in 2004 to the time construction began. Since then, costs for concrete, rebar and other basic materials have jumped significantly.

Looking back on the interval between submitting its bid and the current cost climate, “You couldn’t pick a worse time” in terms of price escalation, McCormack says. While the contract included escalation clauses, these were outstripped by the rise in materials costs, he adds.

The team worked with Fulton County to value engineer aspects of the project and nibbled away at the deficit, he says.

Fulton County’s Williams says that the initial bid of $137.6 million still stands and that any adjustments made by Archer Western have not compromised the quality of the project.

With the architectural work on the administrative buildings under way, the next major steps for the project include finishing the building interiors, installing the ZeeWeed BMR process equipment and the landscaping work. Construction completion is scheduled for July. After a four-month acceptance testing process, the plant is scheduled to go online in November 2009.