By Myrna Trauntvein
A small brass fitting that split was the cause of a water tragedy in Mona.
Jonathan Jones, city water operator, and Andrew Robinson, SCADA system designer, met with the Mona City Council to discuss what Robinson referred to as a “tragedy.”
“It was this brass fitting that caused all the trouble,” said Jones. “I will let Andrew do the talking.”
Bill Mills, mayor, said he would like to thank Jones and Robinson for their work in getting the problem under control. He said he knew that Jones had spent long hours working to get the tank back under control.
SCADA (Supervisory Control and Data Acquisition) is an integrated database. It offers always up-to-date analytics and intuitive dashboards that make it easy to measure performance across sites.
Browser-based HMI screens that automatically resize to fit any device help water operators keep a finger on the pulse of operations from anywhere in the world.
SCADA can instantly respond to alarms by instantly adjusting set points and triggering remote emergency shutdowns from anywhere the second the operator receives email and text alarms.
“You have two tanks,” said Robinson. “One holds 350,000 gallons and the other holds 250,000 gallons.”
They are referred to as Upper Tank #1 and Upper Tank #2.
Usually, he said, a water tank is lower in the daytime and then recovers during the night.
“On the 19th of August, you had an event,” Robinson said.
Consumption on that day exceeded the amount of water coming into the tank.
Tank # 1 is fed with well water and tank #2 is fed with spring water.
The spring produces 1,000 gallons per minute and that production stayed the same. However, at 5 a.m. on the 20th, the tank tipped down and hit the bottom of the tank. The water was leaving the tank faster than it was coming in via overflow.
Using the SCADA system, he said, they were able to isolate the line and determine the fault. The emptying of the tank was caused by the brass fitting which had split and would not let the tank recover.
“In hindsight, we know that the altitude valve was to blame and that it had happened before,” said Robinson.
The day before, he said, the fire department had been testing three fire hydrants. The failure was not their fault but the valve stayed wide open because of the part failure.
The SCADA system called the city’s FAX number rather than a human.
That has been taken care of and now it will alert Jones’ cell number. His phone will be able to see the data and he will be able to recognize that there is an alert.
“Your daily consumption from that tank (which has a capacity of 350,000 gallon) is 332,000 gallon,” said Robinson. “The day the tragedy happened, 905,000 gallons were used.”
When the alert was sent out, citizens were notified. Once the residents were asked to conserve water, he said, they responded and dramatically reduced use.
“Hats off to the citizens for responding as quickly as possible,” he said. “the water use dropped to 195,000 gallons once they were alerted.”
It turned out, said Robinson, that the same problem with the valve had occurred multiple times in the past.
“The state was able to know right where the problem was,” Robison said.
There are options so that the water tragedy will not happen again, he said.
The SCADA system allows the operator to move backward to view the history of the tank usage and forward to current use.
More bells and whistles could be added, he said.
The valve could be forced to close or to open. The way it was, the valve required repair.
Robinson put a view of the tanks, as they were currently operating, on the screen. It showed that the two tanks were hydraulically connected and gave the current use in gallons from each tank.
“The smaller tank is the east tank,” he said.
The spring water is mostly culinary water and the well is also used for irrigation purposes. When the tank overflows, that overflow goes to the irrigation system.
“The city gets the best water, the spring water,” said Everd Squire, city finance director. “There are other springs and thousands of thousands of gallons go to the irrigation company.”
The springs are located before the water goes into the collection box, said Mills.
“How many gallons per minute (GPM) are there in the spring?” asked Mike Stringer, council member.
The day before, said Robinson, the spring produced 199 GPM.
It cycles at 10 a.m. each day and is supposed to produce 240 GPM but the output was 260 GPM.
He said that now that Jones’ cell phone number was programed into SCADA, he would be automatically called if another tragedy occurred. More importantly, he can get the system report know matter where he is.