Provisional plan for dealing with the West Bench boil water advisory

As discussed in a previous update, problems with the West Bench intake and pumping system have resulted in a boil water notice for the West Bench water system.  Many of these problems have existed for years.  However, the view has always been (and still is, according to our recent survey) that residents would prefer not to spend money on upgrading this infrastructure if it will be abandoned soon anyways.  A staff memo illustrating some of the issues has already been posted to this site.

The deficiencies fall into two categories: relatively easy to fix and nearly impossible to fix.  The relatively easy-to-fix problems are the various screens and control system deficiencies.  The screens in particular need to be fixed in order to keep birds and vermin out of the wet well (which, not surprisingly, is seen by residents as intolerable). These repairs have been ordered.

The nearly impossible to fix problem is apparent infiltration of groundwater into the wet well.  We had a long and informative meeting with the City of Penticton water and engineering staff last week (recall that the City of Penticton has had the contract to operate and maintain the West Bench water system for several years) and they have identified a number of potential culprits.  Unfortunately, identifying and addressing the source of the infiltration will almost certainly require the wet well to be drained, and draining the wet well could have catastrophic consequences.  The core problem is that the wet well is located in the Red Wing swamp.  The same external hydraulic pressure that may be pushing swamp water into the wet well could overwhelm the concrete walls if the well were drained (the compensating hydraulic pressure from the full well would be removed).  Draining the wet well could, under a worst case scenario, cause the whole concrete cylinder to be pushed out of the ground.  This would be a very bad thing.

So here is the bottom line as of late October, 2011:

1. RDOS staff, the City of Penticton, and Focus Engineering (as required) will work as quickly as possible to address any deficiencies that may lead to the introduction of animals into the West Bench drinking water supply.
2. We will not, in accordance with the wishes expressed in the survey, attempt to address the infiltration problem.  There is some risk that, by doing so, we would end up in a much worse situation (e.g., no ability to pump water from the lake).  What this means is that the current boil water notice might not be lifted by IHA until a new water system for the West Bench is in place.