Evaluating the Source of Elevated Groundwater Phosphorus Levels in Western Wisconsin Through Sequential Extraction Geochemistry

Abstract

The overabundance of nutrients in water can lead to eutrophication, or the excessive growth of harmful algae and plants. The effects of lake eutrophication include deteriorating water quality and detrimental impacts to aquatic biodiversity. An ongoing investigation of surface water and groundwater chemistry has identified elevated phosphorus levels in lakes, streams and groundwater throughout western Wisconsin. Although phosphorus is widely considered immobile in groundwater, our research strongly suggests phosphorus is mobile and perhaps even concentrating in groundwater. The role of bedrock phosphorus in groundwater must be assessed through a sequential extraction technique that quantifies phosphorus mobility under natural conditions.