Acadiana gets better treatment
New Iberia, Lake Charles plants add capacity to growing regions

By Jim Bradshaw

About $40 million in new wastewater facilities in Louisiana's Acadiana region will add much-needed capacity for the cities of Lake Charles and New Iberia by fall 2005.

Cajun Constructors of Baton Rouge is general contractor for the New Iberia facility. McInnis Brothers of Minden heads the Lake Charles work. Each of the contracts is valued at about $20 million.

The New Iberia plant is under construction on a 14-acre site and is partially the result of a 2001 EPA directive requiring the city to build a new plant to comply with the federal Clean Water Act. The project is being financed by a $20 million bond issue approved by voters in November 2001.

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When construction began in March, about 25,000 cu. yds. of fill was hauled in to build up the site prior to construction, said Steve Harper, Cajun's site superintendent.

"This is true grass-roots construction," he said. "Most municipal wastewater work is adding onto an existing plant. This is start from scratch. There was nothing but sugar cane rows out here when we started."

The 6-million-gallon-a-day plant is designed to handle current and future wastewater needs, said Joe Boles, New Iberia's public works director. The plant is designed with the capacity to add two more cells, increasing its capacity to 8 million gallons a day, Boles said.

"The city's need is only about 4 million gallons a day," he added.

Harper said most of the plant components are made of cast-in-place concrete.

"The two Sequential Batch Reactors are the focal points of the plant," he added. "They use aeration to treat the wastewater, which separates the sludge from the water."

The cast-in-place SBRs measure 115 ft. by 290 ft. and contain four cells, each with its own aerator and diffused air system.

"The SBRs rest on spread footings and a slab-on-grade foundation. The slabs are divided by concrete walls," Harper said. Slabs measure 1 ft. 10 in. thick and the walls are 1 ft. 8 in. thick, all reinforced with rebar.

Any sludge that comes out of the SBRs is transported by pipes to a sludge storage tank, then processed and dewatered.

Harper said the 1-million-gallon sludge tank is the only structure at the site that is made of precast concrete. It measures 80 ft. diameter and was supplied by The Crom Corp. of Gainesville, Fla.

Other components of the plant include a 124- by 64-ft. sand filter structure that removes remaining solids; a 95- by 67-ft. chlorine contact chamber that chlorinates and de-chlorinates the liquid wastewater; a 42-in.-diameter reinforced concrete pipe that discharges the treated liquid into a nearby canal; a chlorine building; a storage building; and a control/electrical building.

The plant's filtration system, supplied by US Filter of Ames, Iowa, will include an underdrain system, wash troughs, media/filter controls and 20 filter cells.

Constructed of corrosion-resistant HDPE plastic, the system offers corrosion resistance with little maintenance. To minimize overall maintenance requirements, stainless steel wash troughs were also included in the design.

Harper said most of the plant's concrete pours are performed from 1 a.m. until 8 a.m.

"That kept the temperature down and enabled us to break and build forms during the day," he added.

Concrete supplier Baldwin Ready Mix of Baldwin also prefers nighttime deliveries because it frees up concrete trucks for other projects during the day. The company will supply about 20,000 cu. yds. of concrete for the New Iberia plant. About 1,650 tons of reinforcing steel is being installed in the concrete.

"We pumped the concrete during the larger pours because it was much quicker," Harper said. "Some of the pours were as large as 600 cu. yds."

The new plant will replace an older one on Admiral Doyle Drive in New Iberia. Cajun will also build a new lift station at the old location.

A 30-in.-diameter force main will ultimately transport the wastewater from the lift station to the new plant and should be on line by the conclusion of the project.

Harper said Cajun is "way ahead" of schedule.

"The month of June killed us because of the rain," he added. "We got a little behind then. But we've had dry weather since and have been able to make it up." More than 12 in. of rain fell in New Iberia during June, according to records at the Acadiana Regional Airport in New Iberia.

At the peak of construction, nearly 140 people will be working at the site. The firm of Domingue & Szabo of Lafayette engineered the New Iberia work.

Lake Charles. A wastewater facility project on Lake Charles' Tank Farm Road is the first of three planned phases, said Sam Bethea, senior project manager for McInnis Brothers.

The project is billed at $17 million, but there is another $4 million of owner-furnished equipment that McInnis will install, Bethea said.

"This is a new plant, with all of the structures involved," he said.

Construction began in March 2003 and Bethea anticipates completion by September. When it goes on-line the plant will add capacity to treat 4.5 million gallons per day of wastewater.

Wayne Harris of Meyers & Associates of Sulphur is the project engineer

Property has been acquired for phases 2 and 3 of the project, Bethea said.

"It is designed and laid out so that these can just be attach to double and triple capacity," he added.

The new facility is the first substantial expansion of the Lake Charles treatment system since 1983, according to Ernie Williamson, wastewater director for Lake Charles.

Also included in the project are improvements to the 18th Street wastewater plant built in 1963, one of four existing treatment plants in the city. All of the plants are working at or near capacity, Williamson said.

"We are going to divert about one-third of the flow from 18th Street to the new

plant and also use it for growth of south Lake Charles, Williamson said.

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