|
Friday's Internet Edition, November 21, 2008.
Gas leak at wastewater plant calls for Haz Mat team
Leaky valve causes chlorine overload
By Rachael Ackerman
Herald Editor
-
While one of the scariest potential problems facing any municipal waster water treatment system still dependent on chlorine gas, a leak at Galt’s plant on Monday night proved the emergency systems set to handle such a crisis are set and ready to go.
Notified by an internal alarm system at the plant on Monday night just before 8:30 p.m., the Galt Police Department made all of the necessary calls to tackle a potential disaster at the city’s wastewater treatment plant.
“The alarm goes to the police department identified as a chlorine leak so all of the emergency responders know what they are dealing with right away,” said Galt Public Works Director Gregg Halladay. “Once everyone was contacted we all met at the sewer plant. Once on site, it was confirmed that there was a hazardous materials leak taking place.”
Halladay said that two parts per million of chlorine in the immediate atmosphere is considered safe for human exposure. The external sensors on the building in question showed the chlorine content of the room to be at eight parts per million, unsafe for human contact, which triggered the call to the Sacramento County Fire Department Haz Mat Team, that contracts for hazardous materials issues in Sacramento and the surrounding areas.
“Once the level of chlorine precluded us, or fire, from going into the building, Haz Mat had to be called out to handle the situation from there,” said Halladay.
On scene, said Halladay, Haz Mat donned their protective gear and entered the room. Once inside, the team inspected the system to determine the cause of the leak before shutting off what turned out to be a broken valve. The leak was occurring between two one-ton chlorine tanks, about six feet long and six feet high, and caused what the fire department deemed a level 2 hazardous materials incident.
“Haz Mat made the call to open the windows and doors of the building to vent the chlorine at that time,” said Halladay. “There was no gaseous cloud. No one, human or animal, was injured and there were no damages caused as a result of the leak.”
Upon further inspection, Halladay reported that a chlorine pump malfunctioned causing the pressure to drop in the chlorine distribution process. With the failure of the pressure relief valve, the system released the chlorine into the building, just, according to Halladay, like it is supposed to.
“It is designed to release into the building and send an alarm to the police simultaneously,” said Halladay. “The system absolutely functioned as it was supposed to in the event of a malfunction.”
The Cosumnes CSD Fire Department, which provides fire and emergency medical services to the city of Galt, was dispatched to the scene, arriving with an engine, ambulance and battalion chief.
The CCSD also activated the Cosumnes CSD decontamination unit, which brings a specialized trailer with equipment to decontaminate Haz Mat teams after members are exposed to hazardous materials. The last units left the scene at 12:22 a.m.
As of Tuesday afternoon, the system had already been inspected and the offending valve shut off.
“There are two valves in the system so, when we shut one off, we still have another to rely on to run the system without any loss of service,” said Halladay. “On Wednesday, the contractor will return to replace both valves and inspect the entire system again.”
Halladay said his department does not believe the incident was related to any human error; instead, they believe it was an equipment failure.
“It’s certainly not a good thing to have happen, but it’s also certainly not unheard of,” said Halladay. “We believe we had an equipment failure, which led to the pump malfunction, which, in turn, performed exactly as it should have in venting and sending an alarm.”
Run smoothly and without further incident or damages, the call to the wasterwater plant for a chlorine leak was a bit of a deja vu for the emergency responders.
“We had a practice drill on this exact same type of incident at the plant about eight or nine months ago,” said Halladay. “We went through a simulated chlorine leak, a sort of dress rehearsal for this exact scenario. As a result, this was a textbook case of how to respond to a chlorine leak, and how to remedy the situation, and it really proved the value of our training in terms of how to respond.”
|
|
