FPUD approves additional Rattlesnake Reservoir re-coating work

An additional change to the contract to re-coat Rattlesnake Reservoir has added $60,226.12 to the project contract and extended the completion date to Aug. 30.

A 5-0 FPUD board vote July 27 approved the amendment to the contract with Simpson Sandblasting and Specialty Coatings, Inc. The total contract amount was increased from $532,940.86 to $593,166.98 while 14 days were added to the previous Aug. 16 final completion date.

FPUD budgeted $600,000 for the project. "Even with the additional work it still came under the engineer's original estimate," said FPUD general manager Brian Brady.

FPUD has a planned maintenance program which re-coats the interior and exterior of steel tanks to protect them from corrosion. A dive inspection of all tanks identified those which require immediate action due to the deterioration of the painting system, and Rattlesnake Reservoir was among the tanks determined to need immediate attention.

FPUD staff prepared a bid package for the re-lining and repair of Rattlesnake Reservoir. Four bids were received by the Jan. 14 deadline. The $457,000 bid submitted by Simpson Sandblasting was the lowest, and on Jan. 26 FPUD's board voted 4-0 with Milt Davies absent to award a contract to the Corona company for the re-coating of the reservoir's interior and exterior.

The tank was drained for the construction work and, when the rafters were inspected, the existing structural bolts which connect the tank shell to the roof were discovered to be corroded. It was also determined that additional piping modifications were necessary to provide additional seismic protection and protect the tank's structural integrity in the event of an earthquake.

The first change order to the contract was approved on a 5-0 vote April 27. That called for the replacement of approximately 850 bolts with Simpson Sandblasting replacing all nuts, bolts, and washers at the rafters and girders with hot dipped galvanized nuts, bolts, and rafters.

That contract amendment also called for Simpson Sandblasting to slurry and weld a plate over the existing 10-inch pipe and create a new 10-inch connection on the side of the tank. That change order increased the contract by $75,000 to $532,940.96 while changing the contract completion date from July 7 to Aug. 16.

The bolts were replaced, and sandblasting on the ceiling and shell began. An additional coating was discovered. The coating material and the date of the coating preceded available FPUD records, so the district was unaware of that coating and it was not identified in the contract. The coating could not be removed as quickly as the epoxy coating specified in the contract.

The sandblasting of the rafter area also exposed additional areas with corrosion and the need for structural replacement of those. "As they were performing the work for the rehabilitation, they found additional corrosion," Brady said.

FPUD staff and Simpson Sandblasting worked together to minimize the cost impacts of the change. The change order includes the removal of the additional coating and the welding of steel supports to the existing rafters.