URBAN STREAM SEDIMENTS AS INDICATORS OF ENVIRONMENTAL IMPACT

The heavy metal content in sediments of an urban stream is investigated as an indicator of contaminant impact. The study focuses in Galloway Creek, an urban stream within Springfield, MO. Metal values are compared to two other streams within the urban area of Springfield whose chemistry are reported; Ward Branch and Jordan Valley Creek.

Sediment samples are collected at 17 sites along Galloway Creek and their location is recorded by GPS. Laboratory analysis of the samples include organic matter and heavy metal content. The heavy metal concentration is found by using a two-step extraction procedure; 1 M Na-acetate and concentrated nitric acid. The results are compared to values of the same samples that are sent to a commercial laboratory and analyzed for heavy metals using aqua regia as extractant. By determining the metal content at different stretches of the stream, this study will help determine the measures needed to improve its water quality and set guidelines for the future of other urban streams. The city of Springfield has recently tried to mitigate contamination reaching these streams by building greenway paths alongside them. Monitoring the stream sediments for heavy metal content will also help determine how effectively these measures have been to deter the input of contaminants into the streams.