Project of Excellence - Fru-Con Builds Firm Foundations for $73 Million

New Design Road Water Treatment Plant Expansion

Fru-Con is building firm foundations as it triples the capacity of a water treatment facility in Tuscarora, Maryland — literally and ecologically. Fru-Con began work on the New Design Road Water Treatment Plant in January 2008 after winning a $73 million contract award from Frederick County to expand plant capacity from 8.8 million gallons per day (MGD) to 25 MGD. The project will be delivered in phases, with the new wing of the plant slated for commissioning in January 2010, followed by total completion on or before June 16, 2010.

The Fru-Con team is working in close collaboration with members of the Department of Engineering and Planning within Frederick County’s Division of Utilities and Solid Waste Management to achieve the project goals. Engineering team members include Rummel, Klepper, and Kahn, LLP, of Baltimore, Maryland, in association with the Baltimore office of Hazen and Sawyer, Environmental Engineers and Scientists.

Challenging Geology

The subsurface at New Design created a challenge in three dimensions. Because groundwater tends to create voids over time, "sound" geo technical testing and advice were critically needed.

First, before any vertical construction could commence, Fru-Con was compelled to address the unique sub-surface condition of the four-acre site. The plant rests on a “karst” geological formation one-and-one-half miles from the Potomac River. Since karsts are pocked with sinkholes, caves and underground drainage systems, the subsurface at New Design is actually beneficial in that it supports the water supply infrastructure of the plant. Conversely, its tendency to develop voids over time creates unstable terrain and routes for contaminant migration.

“Following consultation with a Maryland-based geotechnical consultant, we had eight drill rigs working and an electrical resistivity crew producing 3-D models of what lurked beneath the surface,” recalls Project Manager Brad Smith. “Ultimately, we were able to pinpoint solutions that most appropriately and cost-effectively responded to the specific geological condition found beneath the footprint of a given building.”

Second, in a case of the devil being in the details, Fru-Con found preliminary engineering studies conducted prior to its involvement were overly optimistic. They forecast that 27,000 linear feet of micro-pile would sufficiently support the five new structures destined for New Design. Fru-Con determined that 25,000 linear feet of micro-pile would be required to support just one building — albeit the largest.

“Through various soil engineering techniques — such as compaction grouting, replacement by using compacted geo-textile fabric layers and stone fill – we were able to resolve the issue of foundation integrity for the other structures to the satisfaction of the owner,” Smith reports.

Solving the Lagoon Mystery

Finally, Fru-Con needed to creatively overcome above-ground challenges. To accommodate a new filtration building, a lagoon holding 1.9 million gallons of sludge needed to disappear. The customary solution is to pump off lagoon water, add lime to the sludge to make it solidify and then transport the sludge off-site for disposal. But Fru-Con’s lab tests revealed a high concentration of alum, which would have negated the solidifying effects of the lime.

Fru-Con was stymied, but not for long. After investigating alternatives, Fru-Con Engineering Manager Mike Donnini and his team adopted an ingenious three step plan:

Step 1. The first step was to pump a polymer into the pump stream that caused the solids to separate from the water.

Step 2. Next, with no room on the tight site for auxiliary lagoons to hold the water it needed to pump off, Fru-Con turned to geo-tubes. The giant, rod-shaped woven bags — measuring 30 feet high by 100 feet long — retained 99 percent of the polymerized sludge solids even as they allowed water to pass.

Step 3. After collection in the geo-tubes, the sludge was allowed to dry. The tubes were slit and the solids hauled away. “It took us about five weeks and eight geo-bags to convert 1.9 million gallons of sludge into 6,000 cubic yards of solids,” Donnini notes.

Scale by the Numbers

All told at New Design, Fru-Con is building or installing a new pre-sedimentation basin system, rapid mixers, three flocculation basins, three new sedimentation basins, six filters, four filter effluent pumps, a UV disinfection system, a new chemical feed system and residuals building, a 1.3-milliongallon storage water tank and a new high service pumping facility. It also is upgrading the existing plant and installing a new backup power generation system.

“We are laying approximately 6,000 linear feet of large bore piping, more than 20,000 linear feet of small bore piping and pouring 23,000 cubic yards of concrete,” Project Director Joe Duffy says. “Our team hopes to have all concrete in place by this July.” More than 200,000 man-hours have been recorded at New Design to date, with no lost time injuries or recordable injuries, reports Doug Hill, Fru-Con project safety manager. “We’ll continue working to maintain our zero injuries achievement,” Hill says.

Key Fru-Con project team members include Project Director Joe Duffy, Project Manager Brad Smith, Superintendent David Geesaman, Mechanical Superintendent Brice Criswell, General Foreman/Yard Piping Ed Evans, Assistant Superintendent Nelson Romero, Engineering Manager Mike Donnini, Commercial Manager Elizabeth Thomas, Project Engineer Randy Stedman, Process Engineer Sian Campbell, Mechanical/Instrumentation & Control Engineer Khalil Elshazly, Scheduler/Project Engineer Hao Lee, Field Surveyor David Reid, Engineering Assistant Karen Jenners, Project Safety Manager Doug Hill, Administrative Assistant Abbey Horner, and Accounts Payable Clerk Teresa Case.