Officials believe they have found cause of discolored water

The Cairo Mayor and Council met Monday night with the city’s consulting engineer to discuss issues regarding the city’s drinking water supply.
Two unrelated topics were the major focus of the discussion—discolored water and the rupture of a 16-inch water line on Nov. 14 that left most of the city without water.
Consulting engineer Stacy Watkins told city officials this week that the cause of the discolored water experienced over the last several weeks has been determined.
According to Watkins, a fiber optic cable cut during construction going on at the Cairo Municipal Airport two to three months ago took city well #11 out of service leaving only well #10 to serve the water needs of the city.
Extensive testing revealed that the water coming from well #10 had higher levels of iron and hydrogen sulfide than water drawn from well #11. Watkins says because of the different water characteristics, chlorine should have been injected at a higher level. The media used in the arsenic treatment vessels at the airport water plant is iron oxide based and Watkins explained that the combined chemistry produced the discolored water.
Watkins said that representatives of Denora, the city’s vendor for the arsenic treatment center, had been on-site and assisted city personnel and himself in getting “to the nitty gritty” of the problem.
The consulting engineer said that Denora officials are also revising the operation manual for the plant to provide chlorine residual readings to help prevent this situation from occurring again.
“So, you are saying the problem is solved?” Councilman James H. (Jimmy) Douglas asked. The councilman said he had received a call since Thanksgiving from a resident complaining about discolored water.
“There are small dead end lines and lines that are cast iron, which could produce colored water. You will get that regardless. We have a little better idea of how to operate and test at the plant. What we discovered is that the chlorine residual coming into the vessels needs to be close to what’s coming out, otherwise you’ll have issues with the media,” Watkins said.
Councilman Lannis Thornton questioned why city officials had not been alerted the line had been cut, but Watkins said city officials were aware of the problem and that well #11 was offline.
“What we didn’t know were the iron levels and hydrogen sulfide levels were that much higher in #10 than #11,” said Public Works Director Darin Todd.
Mayor Booker Gainor said that without confusing the different issues would the engineer explain what constituted a boil water advisory.
Todd said that under state regulations if the system’s pressure dropped below 20 psi, a boil water advisory was required. The city public works director also explained that the microbiologic coliform testing is a 24-hour test. Todd said that the discolored water issue was not a result of the loss of pressure and discolored water did not need to be boiled.
Councilman Jerry Cox reminded the council and public that if residents experienced discolored water it needed to be reported to city officials.
Todd said the city had not received any complaints during the Thanksgiving holiday, but said if residents did have issues to report it and water crews would be dispatched to flush the system in that area.
“Do we need to change the media we are using or just chemically balance it out?” Councilman Douglas inquired. Watkins said the city has adjusted the plant’s chemistry to adjust and prevent the discoloring of the water.
City Attorney Thomas L. Lehman said for many years he had been concerned when the city’s only source of water had been the wells and treatment plant located on MacIvor Drive. “What is the timing on getting that plant and those wells back on line? If it had been on line would we not have had this problem?” Lehman asked.
Watkins said a pre-construction meeting would be held in the next couple of weeks and a notice to proceed on the rehabilitation of the #2 water plant would begin early next year. It will be a yearlong process and arsenic treatment capabilities will be added to that plant similar to the airport plant.
The consulting engineer explained that once both plants are operational, the system will be charged alternately by each plant. Likewise, high service pumps on the city’s wells will operate alternately.
Approximately 10-12 years ago, Watkins developed a master plan for the water system, which included a loop around the city. A critical next step, according to the engineer, would be to loop the airport plant down GA Hwy. 188 to the Hilltop elevated tank. If the loop had been in place Nov. 14, Watkins said, the ruptured line could have been by-passed and the city likely would not have lost water service.
The boil water advisory issued Wednesday, Nov. 14 resulted in all local restaurants being closed most of Wednesday and all of Thursday before the advisory was lifted and restaurants could reopen Friday morning, Nov. 16. The water outage also forced Grady County Schools to close early on Nov. 14, but by serving prepackaged food on Thursday, Nov. 15, schools were able to reopen Nov. 15.
Councilman Jerry Cox asked if the loop project should be put ahead of the #2 water plant rehabilitation project. Watkins said the #2 plant project had been bid and construction was set to begin early next year and that no design work had been done on the loop project.
“That should be the city’s next large capital improvement,” Watkins said.
Cox also questioned Watkins and Todd about the cause of the rupture. Todd said he had been in contact with pipe manufacturers to examine the pipe.
Watkins said the line had been in operation for two years and had been pressure tested and passed.
Cox requested Watkins and the city staff meet to begin making plans for the loop project.
“The outage was devastating to this community. We need to do whatever necessary as quickly as possible to eliminate that risk,” Councilman Cox said.
“Yes sir, I agree with you. It has been discussed in the past. It’s a matter of economics,” Watkins said.
Cox added, “We are judged on how we react. Let’s move quickly on alternative action. I appreciate what you do. I know it (the outage) was a challenge.”
Cairo City Manager Chris Addleton, who has been ill and was absent Monday night, said Tuesday that his instructions to the city staff and consulting engineer had been to try and determine the root cause of the pipe rupture and the discolored water and develop a corrective action plan. “I believe that is where we are and we are making progress and moving forward,” Addleton said.