7/30/09
With the Stage 4 water restrictions lifted last week and construction beginning to repair Tank 2, Española city staff are trying to make sure the same neglect that caused Tank 2 to fail does not occur again.
Commercial divers from Colorado-based Inland Potable Services inspected the tank in February and found enough corrosion in around a quarter of the inspected features to give them a rating of “Poor”, which is defined in the diver’s report as “major problems, fix now.”
The floor, which gave out and caused the failure, is listed in the report as “in poor condition with 75 percent corrosion noted and pitting over 3/16th inches deep.” A leak was also noted in the tank’s foundation.
However, this report only touched the tip of what was wrong with Tank 2, because the tank was not drained, Public Works Director Ben Ortega said.
“(The divers) didn’t get to the bottom of the tank,” he said. “They only took what they could see.”
One inspection made following the tank’s total failure on July 13 found over 75 holes in the bottom of the tank. Two such inspections were made in the wake of the emergency, and both say it was evident the tank had not been properly maintained throughout its life.
“It was very obvious, due to the amount and color of the silt/sand on the floor, that the tank had not been cleaned or inspected, at least every five years,” the report made by engineers from D&R Tank Company stated. “Had the floor been cleaned, the numerous holes in the floor would have easily been detected and the true extent of the repairs needed could have been assessed.”
Ortega said he agrees with D&R’s assessment, and currently plans to have all the other storage tanks in the city drained and inspected over the next few months to determine whether any of them are in similar need of repairs. “Those holes did not occur overnight or in the last six months, but over years,” he said. “We have to have an active maintenance program.”
Water Director Marvin Martinez said Tank 2 had been drained and cleaned several years ago, and the results of that inspection were included in the city’s Water Management Plan in 2000.
“This hasn’t been a build-up of 20 years, but the last four or five,” he reported to the City Council at a workshop July 22.
The latest inspections were made by D&R and an independent structural engineer from the Albuquerque office of Wilson and Company, an engineering and architecture firm.
Ortega said he feels that their reports indicate a problem the city needs to address, regardless of precisely when Tank 2 was last inspected.
“We’re being proactive,” he said. “I want to keep this from ever happening again.”