FORT GRATIOT TOWNSHIP, Mich. – Officials are sharing what they think caused a water main break that temporarily affected drinking water for more than 930,000 Metro Detroit residents in August last year.
On Aug. 13, 2022, a 10-foot-diameter water transmission main in Fort Gratiot Township failed, initially sending more than 20 communities under a boil water advisory due to a believed pressure change in the water flow. Following an investigation, the Great Lakes Water Authority now says “pressure spikes do not appear to have played any role in the failure,” and instead mortar damage caused the break.
Recommended Videos
“Preliminary inspection of the failed length of pipe indicates that the failure of the pipe appeared to be the direct result of the mortar coating being adversely affected by the environment allowing for a combination of corrosion and hydrogen embrittlement induced damage of the prestressing wire,” the GLWA report reads.
“Cause of the mortar damage is unknown, however a ditch between fields located directly above the break location could have created an environment that was detrimental to the mortar casing,” officials said Friday.
The water system, which delivers drinking water to residents from the GLWA’s Lake Huron facility, was reportedly operating normally before the main break occurred.
Following weeks of repair and delivery delays, the water main resumed normal operations in October. Repairs were initially set to be finished by Sept. 3. The initial boil water notices issued in August lasted only for a short period of time, though residents in affected communities were asked to limit their outdoor water use amid the weekslong repair project.
The system seems to have been running smoothly since resuming operations.
The GLWA intends to assess 21.5 miles of transmission main starting this year to inspect the pipe for any additional risks or troubles. Officials say 4.5 miles of the main adjacent to the break was already inspected during the repair project.
You can see the GLWA’s incident report on the issue below.
Here are more photos from the main break and its repair.