City response to toxic gas at Kyrene water plant under scrutiny

Tempe taxpayers are on the hook for a contractor's bill that has topped $302,000 and is still ballooning for work that some say could have been avoided if the city had followed recommendations outlined more than two years ago.

The city hired the contractor after an industrial accident last year at Tempe's Kyrene Water Reclamation plant exposed five municipal workers to toxic gas levels that exceeded state and federal regulations. City workers have refused to enter the room where the gas has spiked until improvements are made. So Tempe has kept the contractor on its payroll for more than a year to service equipment municipal workers used to maintain.

Following the accident, Tempe's Risk Management office launched a standard safety investigation that revealed the city was warned as far back as 2006 about problems at the plant that could expose workers to dangerous levels of hydrogen sulfide gas, yet had failed to implement many of the recommendations intended to limit those levels.

Now, several of the municipal workers have hired an attorney, as has the city, and the Arizona Division of Occupational Safety and Health has investigated safety risks at the plant.

History

Starting in 2004, the Kyrene reclamation plant underwent an expansion to handle more sewage. As the plant prepared to re-open in fall 2006, a string of Tempe public documents began to show mounting concerns about hydrogen sulfide gas in the bar "screens" room, the entry point for Tempe's raw sewage. As sewage decomposes, toxic hydrogen sulfide gas is formed.

• In January 2006, a Tempe Environmental Health and Safety assessor reported concerns about hydrogen sulfide gas levels in the screens room and recommended Tempe Water Utilities Department place permanent meters in the room to monitor gas.

More than two years passed before Tempe added those meters.

• A June 2006 e-mail from Kyrene construction management consultant CMX to the city and Wilson & Company, Kyrene plant expansion design engineering company, stated, "You asked me to do a little research on OSHA's recommendations for exposure to (hydrogen sulfide) gas. I believe that the (gas) in the atmosphere of the screens building regularly goes well beyond 10 (parts per million) . . . If someone did get sick, there would be great liability for the City of Tempe . . . "

• In July 2006 letters,Wilson staff said Tempe had not informed the company about its 10 ppm limit during the expansion and advised the city "there may be times when the levels exceed 10 ppm regardless of any features incorporated into the design." Wilson recommended Tempe add a chemical to sewage before it enters the plant to reduce gas levels and also recognize the higher OSHA exposure limits.

In 2007, Tempe added a chemical to sewage for about a week but did not measure its effect on gas levels in the screens room and waited another year before using chemicals again.

• In the summer and early fall of 2006, CMX and the Kyrene staff, according to Kyrene plant team leader Glenda Nichols, urged Tempe to test the hydrogen sulfide gas levels as well as to revamp the screens room to increase ventilation and help lower gas levels.

Tempe temporarily installed monitors, which recorded gas levels as high as 308 ppm and 192 ppm.The National Institute for Occupational Safety and Health, a division of the Center for Disease Control, classifies hydrogen sulfide levels at or above 100 ppm as "Immediately Dangerous to Life and Health" concentrations. People were not in the room when those levels were recorded.

Tempe also placed mats on the floor grating of the screens room to help keep gas below the grates and redirected an air-exhaust line, two things CMX reported helped.

But CMX warned the gas may spike again in summer months when heat speeds the breakdown of sewage, increasing hydrogen sulfide gas. CMX advised Tempe to re-test gas levels when the weather began to get hotter. Tempe did not do that.

• In August 2006, Siemens Water Technologies, a contractor that serviced Kyrene plant equipment, found that gas levels were often above Tempe's standard of 10 ppm. It recommended Tempe enlarge the size of the screens room's air duct to increase ventilation and add a "scrubber" system to help remove hydrogen sulfide gas from the air.

Tempe did not follow either of those recommendations.

Don Hawkes, Tempe's Water Utilities Department manager, said Tempe has estimated a scrubber would cost about $250,000 and would not guarantee an end to future gas spikes.

"It's an expensive thing and it has operating costs associated with it," he said.

Accident response

On Sept. 7, 2007, five Kyrene workers were exposed at least twice to hydrogen sulfide gas levels that exceeded OSHA regulations.

Tempe's Risk Management Department safety investigation blamed the industrial accident on not having workers use respiratory-protection equipment, inadequate engineering controls in the screens room and a lack of administrative controls including not using a chemical to moderate gas. The risk management report called for Tempe to reexamine past recommendations.

At that point, plant workers said they were not willing to risk their health and refused to work in the screens room until permanent changes were made to lower the gas.

In October 2007, Tempe hired environmental-services contractor Philip Services Corporation to maintain the screens-room equipment. When PSC workers enter the room they wear respiratory equipment and carry an emergency airbag.

Nichols said PSC services the equipment for about two hours daily Monday through Friday and the Kyrene staff maintains the rest of the plant. As of early August invoices, that work has cost taxpayers' more than $300,000.

Hawkes said the city has acted responsibly, adopting nearly all of risk management's recommendations in the past year, including in Julyfollowing through on the 2006 recommendation to place permanent gas meters in the screens room and in August began adding a chemical to sewage.

However, Kyrene workers said Tempe chose gas meters that do not measure above 50 ppm.

"We don't even know how high gas (really) gets in there because the city chose those monitors," Nichols said.

Four of the five Kyrene workers involved in the accident have hired an attorney to protect them from what they consider to be retaliation for speaking out about the gas problem.

Tempe has hired a lawyer to investigate Water Utilities Department personnel complaints and the Kyrene plant issues, at a cost to taxpayers of $125,000. The results of that investigation are expected next month.

Hawkes maintains hydrogen sulfide gas spikes at reclamation plants are inevitable.

"That's just the nature of the beast," he said. "To try and convey that there's a 100 percent permanent fix on this (gas problem) is erroneous."

Still, in July, Tempe contracted Wilson for $44,900 to draft designs that include a 2006 recommendation to increase Kyrene screens room's air-ventilation rate. But that work has been put on hold, Hawkes said, pending the results of a $64,571 plant evaluation the city has hired Greeley and Hansen to conduct. Their study is expected in December, he said.

Last month,ADOSH opened a formal investigation into the hydrogen sulfide gas problem and did not cite the city because Tempe is currently not exposing its workers to gas and is considering increasing ventilation in the room, according to Darin Perkins, Arizona Division of Occupational Safety and Health director. But he said the investigation could be re-opened if the ventilation changes are not made.

Nichols said she had called ADOSH because the city is dragging its feet on safety recommendations, choosing instead to duplicate studies, delay solutions outlined years ago and allow taxpayers to pay the price.

She said she hopes ADOSH and the lawyers' will push the city to act.

"It's simple. I want them to fix the building . . . stop the retaliation . . . stop wasting taxpayers' money...provide us with a safe work environment so we can get back to doing what we do best and that's providing a service to the citizens of Tempe," she said.