Binghamton, N.Y., and Johnson City, N.Y., and their joint sewage board have gone back into court, detailing design and construction mismanagement problems at the sewage treatment plant where a 100-ft wall collapsed in May.

Defendants now include 10 engineering or construction firms as well as four insurance firms, which are are involved in the $67-million, phase-three upgrade to meet state environmental standards for the outflow that feeds into the Susquehanna River.

Leading the defendants are C&S Engineers Inc., and C&S Companies, Syracuse, N.Y., the engineer-of-record and construction manager for the expansion, and C.O. Falter Construction Corp., Syracuse, which did general construction for the project.

Repairs and reconstruction will cost more than $20 million, according to the lawsuit. Structural studies showed "many fundamental design and construction errors, omissions and defects," and "large sections of the concrete cells were overstressed and structurally unstable," the suit contends. The structural review and other reports found "design, safety and construction flaws, defects, errors, omissions and deficiencies in the design, construction and oversight of the Phase III improvements," it says. The studies show "substantial portions of the structural, mechanical and operational systems at the BJC plant had not been properly designed by C&S," the suit says. "The BJC Plant is not capable of being used for its intended purposes," the filing says.

C&S, as construction manager, "allowed numerous construction defects, deficiencies and deviations from the design plans and specifications to occur and persist during the construction and installation of the Phase III improvements," the filing alleges.

Bob Duclos, vice president of C&S Engineers, declined to comment, citing "company policy on pending legal matters."

C.O. Falter "used or allowed to be used inferior, unsuitable and defective materials, unskilled and inadequate labor and inadequate equipment," the suit says.

C.O. Falter Construction officials did not respond to a request for comment.

Though work on the plant continued between 2001 and 2009, the suit says "a certificate of final completion has not been issued. As-built drawings have not been produced or submitted."

The plant began "incremental services" in 2007, and "from the beginning of plant operations, defects and deficiencies began to appear in the operation of various plant systems and structures," the suit says.

The plant "never achieved a state where all systems were fully operational."

In 2010, the owner knew the plant had leaks and wall separations. It hired LMK Engineers LLC, Pottstown, Pa., to perform a construction audit. That report, issued in February, found more than 150 construction deficiencies, including "inadequate construction management," "vague or missing" expansion joints between the filtration cells and "numerous leaks" at intersecting cell walls.

Deficiency Reports

Two other engineering firms have studied the plant since the collapse. Both blame the wall failure on construction errors and changes. Fall River, Mass.-based EFI Global Inc. said the collapse resulted from "faulty design, workmanship and/or installation." Modifications made during construction resulted in a structure that was not what construction documents specified, it said.

Simpson Gumpertz & Heger Inc., New York City, found "the majority" of structural elements safe for short-term operation. But it also discovered 34 "significantly overstressed" walls or segments and said the main structures of the damaged area "do not meet the minimum design requirements" of concrete and masonry codes.

The wall collapse sent more than 580,000 gallons of partially treated effluent and rock-like filter media into an adjacent creek and the nearby Susquehanna. The plant is still providing secondary treatment to wastewater.