Community Water Distribution System Freeze Up

Observation by Mike Brubaker: We performed a survey of community water lines in June, September and again in November to see how permafrost thaw and sinking foundations may be impacting water system failures. During the June survey we saw evidence of sinking putting stress on pipe runs and junctions. Now in the winter we see evidence of freeze up in some of the homes where the junction boxes have been compromised, gaps in the insulation and resulting freeze up and overflow of water. Due to ice rich soil conditions, the water and sewer utilities in Selawik are located in an above ground network of insulated utilidors and arctic pipe. These are heavily insulated and must be heated in winter to prevent freezing. But freezing does occur, and there are seasonal water distribution failures effecting entire sections of town. This is in part due to the settling of supports and foundations in the thawing soil. The settling occurs at different rates causing stress and damage to the fittings that connect homes and other structures to the water system. Of particular concern are the junction boxes. Settling of either the pipeline supports or the home foundations cause the seals in the junction boxes to break. Once broken, cold air can infiltrate the seal and can freeze the water in the pipes. During the winter of 2011-2012, repeated freeze-up caused many households to be without water service for most of the winter. Turning up the temperature on the heat tape is not always enough to prevent the lines from freezing, and has resulted in high energy bills for both the utility and individual homeowners. Many junction boxes have been wrapped with blankets or caribou skin to try and restore the insulating seal; and many homes have extended periods without water and sewer service due to frozen pipes. We also documented impacts to waste water system drain pipe into the sewage lagoon and services lines to individual homes. See pull report (attached) for details.