The Effects of a Buried Natural Gas Pipeline on Water Quality, Stream Habitat, and Biotic Populations within High Quality Cold Water Streams in Upstate New York

Denis P. Blais and Daniel L. Simpson, Jr.

A study to determine the effects of a buried gas pipeline on water quality, stream morphology and habitat, and biotic populations was performed on six cold water streams in upstate New York. The six streams represented three general morphological types based on gradient and bottom substrate composition (steep gradient/cobbles and gravel; steep gradient/sand and gravel; gentle gradient/sand and silt). Permanent transects were established upstream of the right-of-way, along the centerline of the pipe, and downstream of the right-of-way for each stream. Four water quality parameters, nine in-stream and stream side habitat variables, and biotic populations were assessed prior to, during, and for three years following construction of the pipeline. The results of the water quality measurements showed no apparent effect on water temperature, pH, or dissolved oxygen during and following construction of the pipeline. The primary impact to the streams was an increase in total suspended solids which occurred during construction activities. Total suspended solids measurements were highest along the centerline transect and decreased by 51% to 82% 100 m downstream. Generally, percent riffle fines, percent pools, the amount of instream cover, the amount of stream side vegetation, and percent mid-day shade all decreased within the right-of-way following construction, while the percentage of gravel and cobble increased. Overall, there appeared to be no long-term effects on benthic invertebrate populations for two of the streams included in the analysis, and fish populations appeared largely unaffected for all six streams.

Keywords: Pipeline, trenching, water quality, stream habitat, benthic invertebrates, fish populations