I am writing today to announce the closure of the New Mexico Independent. After three and a half years of operation in New Mexico, the board of the American Independent News Network, has decided to shift publication of its news…
While environmental activists played their part yesterday during demonstrations at the capitol building, going so far as to dress up as solar panels and to sing the tune of “You Are My Sunshine,” their counterparts, the anti-cap-and-trade contingency who has…
Roughly one quarter of University of New Mexico students are unimpressed with the state’s flagship public school, according to a survey that questioned college students about their higher education experiences.
Photo by Esther Gibbons.
Bernalillo’s new contract water engineering firm has received approval from the state Environment Department to begin using iron treatments this month to help bring the Town’s drinking water into compliance with federal regulations, Mayor Jack Torres told The Independent this week.
Engineering firm Wilson & Company completed a Corrective Action Plan March 26, proposing the iron treatments in addition to ongoing aluminum treatment. The plan was approved March 29 by the state Environment Department, Torres said.
“The Plan was in response to violations the Town received for (exceeding) the maximum contaminant level (allowed) for arsenic in drinking water,” Torres said Tuesday, referring to two recent state Environment Department violation notices for arsenic levels that exceed federal and state standards.
Former mayor Patricia Chavez fired water system engineer Ramesh Narasimhan Feb. 23 and hired engineering firm Wilson & Company to fix the water treatment facilities.
Bernalillo paid at least $4.9 million to build arsenic filtration systems at its two active wells in 2007 and 2008, using equipment produced by Bernalillo-based ARS-USA. Bernalillo was the first municipality in the nation to adopt ARS’s aluminum-based system for arsenic treatment.
Aluminum system failed to bring arsenic to acceptable levels
By summer 2009, residents were complaining about aluminum sludge in their tap water—and lab reports obtained by The Independent showed the systems had failed to bring arsenic levels into compliance with federal drinking water standards.
The malfunctioning system’s operation and maintenance costs have been “dramatically” higher than expected, according to Wilson & Company’s Corrective Action Plan.
The plan calls for the addition of ferric chloride, a form of iron, to well water, in an effort to improve the effectiveness of the existing aluminum-based system at removing arsenic.
Two 12-day test runs will be initiated this month, with water samples taken every two hours for lab testing, according to the plan.
Both iron chloride and electrically charged aluminum attach to arsenic, making the metal-bound arsenic molecules too large to pass through water filters. The Corrective Action Plan also calls for the use of new filter media, switching from current zeolite filters to sand and anthracite (a form of compact coal).
If the strategy fails to bring down arsenic levels, then water pH may be manipulated using other, unspecified chemicals to facilitate iron’s removal of arsenic, according to the plan.
“Ferric chloride is commonly used in the industry for the removal of arsenic and was recommended in previous engineering studies commissioned by the Town,” Mayor Torres noted Tuesday.
In 2006, Bernalillo’s engineering firm of record, HDR, had refused to recommend ARS’s new, aluminum-based arsenic treatment system. Instead, HDR recommended the Town use ferric chloride.
But former Town manager Stephen Jerge then hired a second engineer — Ramesh Narasimhan — who recommended the Town purchase the ARS’s aluminum-based arsenic treatment system instead, citing in part lower projected operation and maintenance costs, Town records show.
Fixing aluminum sludge problem should wait, plan states
Wilson & Company engineers also think they may have identified why the system has been dumping aluminum sludge into residents’ tap water — but fixing it will not be easy or inexpensive, the plan warns, and should be postponed until arsenic levels are under control.
Most treatment systems let discharge water containing filtered sludge sit in a holding tank long enough for suspended sludge to “decant” or settle to the bottom of the tank. ‘Decant’ water is then dumped into a local sewer system and the sludge trucked to a landfill.
But both Town wells sit within the city limits of Rio Rancho, which has no adjacent sewer lines, so decant water has been sent back through the filter system and into the Town’s tap water supply, the plan states. That caused increased aluminum levels in the finished tap water, according to the Wilson & Company analysis. Trucking the decant water to Bernalillo’s sewer system would cost approximately $900 per day, the plan states.
That will likely be necessary if the ARS arsenic treatment system continues to be used, the plan states. Due to the cost, however, Wilson & Company recommended the Town “defer action” on addressing the aluminum sludge issue until the new strategy for reducing arsenic levels with ferric chloride, has been completed.
Flushing the sludge from the water distribution system’s network of pipes fully could take months, the plan speculates.
