Vatovec also recommends:

  • 
Development of warning systems to alert plant personnel if the water level drops below a certain point in the backwash equalization tank and if the water level goes above a certain point in the clearwell, clearwell influent channel and CL2 contact tank influent channel. He also wants warnings if there is more than a 2-ft difference in the water level in any of those three components.
  • 
Installation of a temporary stabilization system for part of the clearwell north wall and bracing at a beam supporting part of the catwalk grating of the clearwell. Until then, only one person should use the catwalk.
  • Banning people and vehicles within 20 ft of the backwash equalization tank east wall, banning vehicles within 20 ft of the pump room east wall, banning parking or driving anything other than passenger cars and pickup trucks next to two N cells and the south wall of the pump room.

He also wants the limitations posted in the plant and parking lots.

And he said the recommendations are good only for 18 months.

“Further investigation and analysis are required to design and implement permanent repairs/strengthening to the overstressed” elements of the plant, he said.

The two cities and the board have filed a $20-million suit against 12 companies, including C&S, charging professional negligence and malpractice in construction. They are asking for repair and replacement of collapsed walls, defects in design and construction and replacement of treatment material.