July 2023 Water Treatment Plant leak mitigation summary

This report is meant to provide our customers with a summary of the events surrounding the water leak at the Water Treatment Plant during the weeks of June 25, 2023, and July 2, 2023, which resulted in a request to our customers to reduce water usage while emergency repairs were made. Though this issue was challenging to address while maintaining adequate water service to our customers in Paris and Lamar County, we are pleased to report that it was successful. Many thanks go out to those contractors and staff who spent long hours managing this situation to a successful conclusion.

On Wednesday, June 28, 2023, water was observed flowing from a manhole situated above 30-inch and 33-inch pipelines at the Water Treatment Plant (WTP). The pipelines are the only means of serving the City with treated water from the WTP. The WTP Superintendent, notified the Director of Utilities, of a potential leak on one of these lines.

JB&L Utility Contractors was contacted Thursday, June 29, 2023, to repair the leak. Primarily due to the 25-foot depth of the pipelines, it was determined that the job was beyond their capability. RBIS, a contractor based in Texarkana, was recommended to make the repair.  RBIS representatives arrived Thursday evening to assess the leak.  RBIS has previously worked on large projects for the City of Paris, including the construction of the Southeast Lift Station in 2018.  That evening the Assistant City Manager, was notified of the situation.

RBIS mobilized equipment to the Water Treatment Plant on Sunday, July 2, 2023, in preparation for beginning excavation the following day.

Excavation began in the area around the leak on Monday, July 3, 2023, to expose the pipelines and determine which of the pipes were leaking, the location of any leaks and severity.

On Tuesday, July 4, 2023, RBIS completed the excavation and began pumping water from the pit to expose the lines.  Leaks were discovered on the 30-inch Reinforced Concrete Cylinder Pipe (RCCP) originally installed in 1965. One leak was from a crack in the bell of the pipe and another from a previously installed tap.  City staff and the contractors met to determine how the leaks would be repaired.

RBIS continued pumping water from the excavation on Wednesday, July 5, 2023, while attempts were made to isolate water flow and pressure from the 30-inch line.

On Friday, July 7, 2023, a coordination meeting was held to review options for the repair. Due to the composition of the pipe, Thompson Pipe Group was contacted to arrange for the delivery of a clamp to be welded onto the pipe. At this time, RBIS began preparing the pipe by removing the outer concrete to accommodate the clamp.

Before the clamp could be welded in place, the pressure in the pipeline needed to be removed.  On Saturday, July 8, 2023, multiple attempts to isolate flow and pressure from the 30-inch line were unsuccessful.  With the requirement of the pipe not being under pressure, additional options were considered resulting in a call to Rangeline, a company specializing in stopping water flow in pipelines by insertion of a device called a Hydro-stop.  This method would result in removing backflow pressure on the 30-inch line.

Sunday, July 9, 2023, City official and contractor representatives met with Rangeline staff at the Water Treatment Plant.  Following his observation of the circumstances, Rangeline developed a scope of work and provided a quote for this service Sunday evening.  The City Manager and Assistant City Manager were provided the quote.

In addition to the exposed leaks on the 30-inch line and based on a reasonable expectation of an additional leak due to the manner in which the excavated area was filling with water, a leak was suspected on the 33-inch line on Monday, July 10, 2023. At this point, water storage levels for the City were well below normal. Discussions now included the concern of the complete depletion of water storage, which would interrupt the ability to provide water for the City of Paris and much of Lamar County. This scenario would have required mandatory water use restrictions and a requirement for the City to issue a boil water notice.  To avoid this situation, a press release was issued requesting customers to make a concerted effort to conserve water and eliminate all non-essential water use.

Rangeline arrived at the Water Treatment Plant on Wednesday, July 12, 2023, and began preparations for the insertion of the Hydro-stop.  Late Wednesday evening, Rangeline successfully completed their work, stopping backflow and pressure on the 30-inch line.

With flow and pressure removed from the pipeline, a clamp was welded over the crack in the 30-inch pipe, the leaking tap on the line was repaired, the Hydro-stop was removed, and the Water Treatment Plant returned to normal operations on Thursday, July 13, 2023.

City Staff were in constant communication as they observed and managed the situation to make sure that should it ever escalate, appropriate steps to communicate with the community would be taken. The City Council received daily updates as the issue and the work progressed. Information was shared with heavy industrial water users as well as emergency-critical users. City Emergency Management maintained communication with our local and state partners in preparation for the worst-case scenario should the situation escalate. At no point was the quality of water impacted, and while water availability was at risk, staff did an outstanding job of handling each situation and make sure water continued to flow to the community. While it is difficult to know with certainty, we believe a manhole resting above the pipe was the culprit for the leak as, over time, the weight resting on the pipe eventually caused it to break. This has been remedied as the reasons for the manhole’s existence, to service some treatment reading gauges, have been rerouted into the treatment facility, thus eliminating the need for that manhole.