Skip to main content

Update on St. Stephen’s well at Maxwell Crossing


Update on St. Stephen’s well at Maxwell Crossing


The Municipal District’s drinking water is supplied by a large diameter primary well and two smaller drilled wells located at Maxwell Crossing.    The primary well is part of the original water system that was constructed circa 1906 and is approximately 9 metres (30 feet) in diameter and 9 metres deep with the bottom open to the gravel aquifer.  The well is observed to consist of a stone foundation at the base with brick walls to the surface and where it is covered by a concrete roof.  In the late 1960's, a second smaller diameter well was constructed approximately 60 metres away and connected to the primary well by a 450 mm diameter perforated pipe that entered through the primary well foundation to improve overall supply capacity.  


On Wednesday March 15, 2023, the Municipal District was alerted of a high turbidity alarm for water coming from the primary well.  In accordance with the Municipal District’s Approval to Operate, a Boil Water Advisory was put in place.  Turbidity levels in the water supply returned to normal until Sunday March 19, 2023 when a second high turbidity alarm occurred.  At this time, a depression in the ground was observed outside of the primary well.  


The Municipal District engaged their engineering firm to investigate.  A submersible ROV with video camera was deployed into the well on Tuesday March 21, 2023.  Observations from the video investigation show that gravel from the aquifer outside of the primary well spilled into the well through an opening that was constructed in the foundation for the pipe installed in the 1960's.  It is thought that the 450 mm pipe collapsed outside of the primary well on March 15, allowing gravel to enter the well through the foundation opening.  The finer particles in the gravel were suspended in the well water for a period of time which triggered the Wednesday alarm.  This left a void space over the collapsed pipe. When the material over that void space collapsed, additional gravel likely entered the well and resulted in re-suspension of sediment, triggering the second alarm on Sunday, and causing the depression outside the primary well to be seen at the surface.  


High turbidity events have not occurred since the second event on Sunday, March 19th.  Multiple days of normal turbidity readings, combined with video observation of the inside of the well suggest that the migration of material into the well may have stabilized for the moment.  The Municipal District’s online monitoring system is in place to detect if additional events occur and a follow up video inspection will be completed at a future date to observe if any visible changes have occurred.


It is also important to understand that when turbidity levels in water are elevated above normal levels, the material causing the turbidity (in this case, material from the gravel in the aquifer) may, or may not be a health concern on its own, but elevated turbidity reduces the effectiveness of disinfection (which the Town achieves by chlorination).  This is why a Boil Water Advisory is important to protect public health.  


The Town will continue to work with their engineers and the Province to monitor for changes, and develop short and long term plans to enhance the resiliency of the Town's water source.