Contractors drilling a monitoring well near the APEC 2 site in Wheatley struck a pocket of hydrogen sulphide gas 85 feet below the surface at 11:05 am yesterday morning.
Safety measures worked as designed and the site was evacuated and there were no injuries. A loud hissing noise accompanied the emission which lasted until 11:20 am.
Thomas Kelly, Chatham-Kent’s General Manager of Infrastructure and Engineering Services, said a mobile vent stack system at the site of the well drilling was successfully deployed which allowed the gas to vent into the atmosphere without incident.
Drilling was stopped and the crew moved out of the hot zone after connecting the well to the prepared vent system to dissipate the gas.
Work has since resumed.
Fire and Emergency Services Chief, Chris Case, credited a well-designed and practised safety plan with ensuring the incident was handled successfully.
“As part of our response plan, we have firefighters 24/7 on-site, they are supported by the Wheatley firefighters who were called. We do not use lights/sirens so as not to cause stress to the local community,” he said.
Additional Chief Officers and Medics deployed on standby as the engineering team continued their work.
On-site hazmat and technicians moved in to check that the area was safe while fire crews and technicians began mobile monitoring around the area.
“We were advised that the event had concluded and that apart from the detectors close to the drill site no gas had travelled creating a risk to the community. All response teams were stood down around midday and the engineers have returned to work. I am pleased to advise that the plans, which are practiced and drilled regularly, worked,” he said.
Kelly said the APEC 2 monitoring well is the first of two monitoring wells to be installed. One well will reside inside the investigation area and the second just outside the evacuation zone. These wells will allow the investigation team to obtain groundwater and gas samples to support the chemical modelling work.
Case said the incident demonstrates the unpredictable and potentially dangerous conditions that can occur and supports the cautious approach taken by authorities to only allow access to properties when work is not underway.
Municipal officials are reviewing a work plan which will establish the next steps on the remediation of an ongoing gas emission situation in downtown Wheatley.
Chatham-Kent CAO Don Shropshire said a plan has been submitted by the firm engaged by the province to lead the project.
“We have a preliminary work plan now under review,” he said. “Once that has taken place, our plan is to hold a virtual public meeting with Wheatley residents and provide information as to next steps.”
Work at APEC (Area of Potential Environmental Concern) 2 to bring the well to the surface is substantially complete. The contractor is awaiting several parts to connect this well to the test separator system. That is expected to be complete early next week
The contractors completed an investigatory excavation at APEC 3 and discovered a brick well structure with a small wooden casing extending from the bottom approximately 12 feet below the surface. Small amounts of methane have been detected emitting from the well structure. Work is currently ongoing to further investigate whether the structure is a water well or a gas well. A laboratory sample will be obtained for analysis.
This week some members of the on-site team were placed under COVID-19 protocol. This will cause minor delays to homeowner access this weekend while staffing resources are re-arranged.
Shropshire said evacuated residents with questions should contact their caseworkers at Chatham Kent Health and Family Services and businesses should contact Economic Development Services. Individuals with general questions are asked to call 3-1-1.
Shropshire urged the community to watch the video of a Wheatley update presentation to Council at its January 17 meeting.
A video of the presentation can be found at https://www.letstalkchatham-kent.ca/wheatley-updates/widgets/112620/videos/8697.
By clicking on the Non-Agenda Business section, the video will begin at the appropriate time.
Shropshire thanked the more than 750 individuals who have registered for an email subscription list to keep them updated. “We’re grateful that so many people want to know the facts and keep up with the latest news. Whether you’re a resident or not of Wheatley you are welcome to subscribe to these updates.”
To join the list, follow this link.
No gas release has taken place since November 21 and given the interval between previous gas leak events, officials are expecting a release soon although topographical changes and cold weather may be having an effect on the site.
Photos one and two are of the well (APEC 3). The third photo is an overhead of the scene with APEC 3 included.
As work continues to connect the second of two wells in Wheatley to monitoring equipment, another 10 individuals were allowed temporary access to their properties during the weekend.
The second well (Apec 2) was brought to the surface last week and workers on site are connecting it to the test separator and installing monitoring equipment as was done with the first well (Apec 1).
The test separator and venting system connected to APEC 1 remains in place which functions to improve the overall safety of the site.
Residents and property owners seeking temporary access to check on their properties are required to register with the municipality for scheduling purposes and to allow emergency personnel to determine if the property is safe to enter.
To date, 69 appointments have been completed and 21 appointments are ready to be booked for properties evacuated but not in the immediate vicinity of the August 26 blast. Officials are still prohibiting access to those sites due to safety concerns.
Access will resume this week when any gaps in the work occur.
Based on the pattern of the last six months, officials in Wheatley are anticipating a gas release within the coming week.
Today is day 45 since the last release and the five previous releases dating back to June 2 of last year all took place between 38 and 47 days of each other.
During the past few weeks, officials have demolished buildings near the 15 Erie Street North site of the August explosion. Excavation work has taken place and two wells have been confirmed.
As a result of the work conducted, the landscape of the area has been changed significantly which officials say may impact the typical cycle time of the gas release.
Preparations have been made to safely vent and capture a sample of gas for further analysis.
The next step of the resolution process will be to bring one well to the surface, drill it and conduct tests with pressurized water to determine if an underground connection exists between the two wells.
Depending on the gas release date, residents may see heavy equipment on site within a week.
Fire and Emergency Services and security personnel will continue to be present at the site.
Resident visits to evacuated dwellings will resume when it is appropriate to do so.