Water Tank Rupture Point Identified

Westminster officials on Wednesday tentatively identified the weak point in a ruptured 5-million-gallon water tank as the area where the floor meets the precast concrete wall.

A city engineer said the area is not in the same section of the reservoir that had shown signs of rust, cracks, rotted caulking and damaged beams during an independent inspection last year.

“None of the cracks mentioned in that [inspection] report could have led to this,” said Marwan Youssef, the engineer.

The city, though, will spend up to $30,000 to determine what happened and how it could have been prevented, Youssef said.

He said a vulnerable point in the foundation was the likely cause of the rupture Monday that sent a 6-foot wall of water slamming into a nearby fire station and the Hefley Square Town Homes.

The water burst from the southeast portion of the dome-shaped, above-ground tank--nearly opposite from the northwest area where the problems were noted last December.

The flood--which washed 100 residents from their homes and left six people injured and 10 families homeless--prompted officials to drain a second water reservoir that is identical to the one that failed.

Engineers hired to determine the cause of Monday’s rupture will conduct a structural inspection of the second tank, near City Hall, next week.

“We’re taking precautions,” said Mary Ann Mulligan, a city spokeswoman hired in the wake of the disaster. “Obviously there are safety concerns and things relating . . . to the tanks that we want to look at and address.”

The December 1997 structural review may have been the first independent detailed inspection for the 30-year-old tank, said Gary Heffelfinger, director of the Westminster Water Department. He said he and other city workers have dived into the tanks to look for problems.

“There’s no law that says we have to inspect them,” said Heffelfinger, who has been with the Water Department for 23 years. “Obviously, it will be done now. Hindsight is 20 / 20.”

Since the flood, city officials have been criticized for not maintaining the 25-foot-tall reservoirs at the same level as tanks operated by other municipal water departments, which hire experts to perform inspections at least every five years. Other departments typically drain the tanks to examine and repair the inside or send divers in to make checks and repairs.

Meanwhile, 10 families in the 49-unit Hefley Square complex were allowed to return home Wednesday. They were able to return only because they had pulled sheets of soggy carpet out of their living rooms and made sure no electrical wires were exposed, Westminster Police Capt. Andrew Hall said.

“That is the threshold for who gets to stay the night now,” he said. “We don’t want to have a fire or another disaster on our hands.”

Ten units will be demolished.

As fire crews continued to clean up the four-block flood site, construction workers hired by the city began shoring up garages and condominium units so residents could safely get inside to retrieve their valuables. A mechanic was dispatched to help neighbors restart their waterlogged cars, 22 of which were totaled and 16 others rendered inoperable.

Building inspectors also were at the site to tally damage estimates for homes, garages, insurance and victim recovery costs, Mulligan said. While structural damage will be in the millions, the retail value of the lost water that caused the destruction totals a mere $9,500, officials said.

“It’s a drop in the bucket, so to speak,” she said. “It’s nothing.”

The tank failure has revived talk about privatizing the department. The city voted 3 to 2 last year to reject a proposal to sell its water department to a private company, a transfer that would have covered costly maintenance repairs and upgrades to the aging tanks.

But water department issues have been contentious for years.

In 1991, Mayor Frank Fry Jr., then a councilman, and two others faced a recall effort after they supported a 100% increase in water rates to provide for capital improvements. The council settled on a 15% increase, which remains the last increase it has approved.

Fry said Wednesday that the reduced rate hike left the department with little extra money. “If something went bad, we fixed it, that was it,” he said. “We did not do any capital project.”

The state Public Utilities Commission inspects private water companies, which provide 20% of California’s water, at least once every three years.

But the state doesn’t regulate municipal-owned utilities for structural problems and doesn’t require regular inspections, said Dean Evans, a water director with the state Public Utilities. “The cities are responsible for their own preventive maintenance,” he said.

Fry said he would favor a state law that would require regular structural inspections of publicly owned water utilities.

Last December, Dive/Corr Inc. in Long Beach reported to the city that a diver found a few beams that displayed unusual “movement,” a term used to describe damage caused by an earthquake.

“It had gone through earthquakes,” Heffelfinger said. “We did visual inspections and there was nothing to indicate that movement by an earthquake caused damage.”

Officials at more than a dozen water districts and city water departments surveyed in the aftermath of the Westminster incident said they perform detailed inspections at least every five years.

The Moulton Niguel Water District, which serves Laguna Niguel, Aliso Viejo and parts of Mission Viejo, Dana Point and Laguna Hills, inspects 30 tanks every three years.

“There’s a diving service that actually goes in and films,” said Jack Foley, the district’s general manager. “They film the inside so we can look at the joints and structure. It’s continuous maintenance.”

In Huntington Beach, divers are sent into the city’s three concrete tanks every two to three years for inspection. The tanks also are drained completely every five years for a more thorough inspection, water operations manager Jeff Renna said.

The El Toro Water District has an “aggressive preventive maintenance” program that requires divers to explore three steel tanks and two concrete tanks every year, said Robert Hill, the district’s assistant general manager.

The city of Orange drains its 15 steel and two concrete tanks every three years for close inspection.

“There’s a little more maintenance for steel tanks, because it has to be painted in the beginning and throughout the life of the facility,” said Joel Wright, the city’s water manager. “You have to maintain that coating system.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Assessing the Damage, Taking Precautions

Safety inspectors allowed 10 families to return to their Hefley Square Town Homes on Wednesday after the residents removed soggy carpeting and work crews restored water and electrical service. Meanwhile, Westminster officials completely drained a second water tank, which will undergo an extensive structural inspection.

Source: City of Westminster

Graphics reporting by BRADY MacDONALD / Los Angeles Times