Nothing on our system had any impact on the customer-owned natural gas lines or customer-owned natural gas appliances in this situation.
We believe that this issue was related to elevated levels of mercaptan, which will often draw attention to even the smallest leaks because of the stronger odor. The leaks our service technicians detected on customers’ facilities and appliances were pre-existing in nature and very small in most cases and not caused by elevated mercaptan levels. These small leaks would likely not have been noticed when mercaptan levels were in the normal range, and it would not be uncommon to find similar kinds of leaks in neighborhoods of similar vintage.
Please note that mercaptan is added to natural gas, which is odorless and colorless, because it alerts customers to the presence of natural gas and to take appropriate actions to stay safe. In this situation, it helped customers identify leaks that otherwise may not have been detected and allowed customers to take remediation actions.
Mercaptan levels in that area have returned to normal levels today and there has not been a widespread effect on our system.
We will continue our investigation, but always remind customers that if they suspect that they smell natural gas, call us at 1-888-460-4332, and a service technician will be dispatched to check to conduct a thorough safety check and inspection.