Project Detail

Trempealeau River 303d Evaluation WCR_02_08

Purpose

The Trempealeau River at Dodge has been monitored for the past several years as a LTT network site. The median total phosphorus concentration at the site is 369 ug/L which is the highest amoung the 42 LTT sites. Concentrations of bacteria, suspended solids and dissolved silica are amoung the highest of other LTT sites. Very limited biological data has been collected from the river and the extent of high phosphorus concentrations are not known. Another unknown, is the impact the high phosphorus concentrations are indirectly having on the biological community. The Department would like to request funds to evaluate the Trempealeau River including a site on both the North and South Branch Trempealeau Rivers at eight locations for fish, macroinvertebrates, continuous dissolved oxygen, continuous temperature, habitat and water chemistry. Fishery and habitat data would be collected during July or August and macroinvertebrates would be collected in the fall.

Objective

The Department does not know if the high phosphorus concentrations found at the Dodge LTT site are indicative of the entire stream and if there is an impairment to aquatic life as a result of high phosphorus concentrations. This project will evaluate both water quality and biological conditions to determine if an impairment exists.