Cranes Kept Busy at NC Phosphorus Reduction Plant

Fri May 12, 2006 - Southeast Edition
David S. Chartock




Two Link-Belt rough-terrain cranes played a key role in the $29-million McAlpine Creek WWMF Phosphorus Reduction project in Pineville, NC.

According to Geoff Doyle, a project manager of Atlantic Skanska Inc., the Atlanta-based general contractor, a Link-Belt 8050 and a Link-Belt 8070, each a rough-terrain crane leased from Atlantic & Southern of Atlanta, were used to set chemical tanks, pumps, sludge processing equipment and precast concrete water sample stations throughout the 1-sq.-mi. project site.

The project is an upgrade and renovation of a 40-year-old facility. Doyle said the scope of work included construction of two new concrete reinforced and concrete masonry chemical processing buildings, two new pumping stations, two new gravity thickeners, six sample stations and renovation of five existing pumping stations to facilitate the 97 percent reduction of the phosphorus in the plant’s effluent water discharge 100 yards into South Carolina lakes.

Doyle said this is a political issue because phosphorus causes excessive algae growth in lakes and streams. He explained that one of the 15,000-sq.-ft. chemical processing buildings has 12 tanks for chemical storage and eight pumps and the second 15,000-sq.-ft. chemical processing building houses 16 tanks for chemical storage and 12 pumps.

The waste water pumped for processing is piped to the plant by gravity-forced sewer mains from Charlotte, NC, just 13 mi. away.

Additional work, Doyle said, included “the renovation of five existing pump stations and the construction of two new pump stations, the construction of two new gravity thickeners that take partially processed sludge and separates the solids from the liquids and installation of six precast concrete sampling buildings to house electronic equipment to monitor water quality throughout the plant.”

Being an existing facility, the project team was faced with performing its tasks while the facility remained operational.

To meet this challenge, the crew phased the project.

“There were two major phases with eight intermediate phases. The first phase consisted of the north side of the plant and the second phase consisted of the south side of the plant,” Doyle said.

The first phase included construction of one of the two chemical processing buildings and renovation of two pump stations. The second phase included construction of the second chemical processing building, renovation of two existing pump stations and construction of two additional pump stations.

A computerized schedule was used for project planning along with a detailed work plan. The detailed work plan, Doyle said, “was coordinated and integrated into the plant schedule so phasing could be done. For example, the point at which the waste water flow was at its lowest was between 4 a.m. and 5 a.m., which facilitated connection to existing plant facilities.”

To keep on top of the project schedule, weekly coordination meetings were held with CH2MHill Architects Inc., the project’s designers, and Charlotte Mecklenburg Utilities, the plant operator, Doyle said.

“We also participated in the Charlotte Small Business Enterprise program. This allowed local small business owners to provide input as part of the project team,” Doyle said.

He pointed out that at the project’s peak, personnel consisted of 85 Atlantic Skanska workers and 25 more working for subcontractors. Weekly work hours ranged from 41 hours to 60 hours per week, with some Saturdays required.

Primary heavy-construction equipment used to perform the required work included, in addition to the leased Link-Belt cranes, were a leased Link-Belt 110-ton tractor crane and a leased Link-Belt 50-ton RT mobile crane. Atlantic Skanska-owned equipment included a Link-Belt 70-ton RT mobile crane, a National 21-ton boom truck and a Caterpillar 322 hydraulic excavator.

The project, which began in October 2003, is expected to be completed in June 2006. CEG