An Army Corps of Engineers report found mechanical and contracting problems with drainage pumps installed by the corps before the start of the 2006 hurricane season, prompting a Louisiana senator to call for a Justice Department investigation.

Although the pumps have been extensively overhauled, critical flaws remain a year later, according to the report, which was released Friday.

The review by three corps engineers from outside the New Orleand district office backed up findings of a May 2006 memo by a corps mechanical engineer working on the $32 million pump project. The memo warned the pumps were faulty and would not work during a hurricane.

The report said devices called flooded suction intakes have not been added to 34 pumps, even though the contract called for making the change since July 2006.

The devices would prevent air being pulled into the hydraulic oil pumps, which would cause failure, the corps report said.

The contractor, Moving Water Industries Corp., has "only provided a vacuum type check valve for priming the suction" to the pumps. The report called the valve "only a facade in addressing the real issue and requires the operation of vacuum equipment to prime the hydraulic pumps."

"If the vacuum is not drawn properly, then the pumps will aerate and create irreversible damage to the components of the pumps," the report said.

The review also criticized documentation of contracts connected to the pumps. MWI is a politically connected Deerfield Beach, Fla., company.

"The contract files are not consistent with established standard procedures," the report said. "Any lack of proper documentation leaves the government open to potential contract claims that would be difficult to defend."

U.S. Sen. Mary Landrieu, D-La., on Friday sent a letter to Attorney General Alberto Gonzales asking for an investigation into "the charges of potential misconduct and reported irregularities" outlined in the report.

The pumps were installed just before the 2006 hurricane season as part of efforts to shore up the drainage system for below-sea-level New Orleans. Since Hurricane Katrina struck on Aug. 29, 2005, breaking levees and flooding 80 percent of New Orleans, the corps has spent about $1.5 billion in upgrading or repairing flood protection.

(Copyright 2007 by The Associated Press. All Rights Reserved.)