This paper reports on a special health concern identified in Point Hope, Alaska during a recent Climate and Health Assessment: disruption of drinking water treatment influenced by temperature driven increases in organic material in an Arctic tundra lake. Blooms of organic material have been observed in the past in the source water lake in Point Hope, but conditions have been extreme over the last two years. If warm temperatures continue, organic blooms will become a reoccurring problem for Point Hope and other communities that depend on tundra lakes for their water supply. Analysis of source water chemistry and biology is recommended, as is an analysis of possible adaptive operational procedures or design modifications that could improve water system efficiency.