Headwater Stream Acidification in the Tuscarora Formation,
Valley & Ridge Province, Pennsylvania - summer 2005

Carl S. Kirby, Associate Professor, Dept. of Geology, Bucknell University, Lewisburg PA 17837
570-577-1385; kirby@bucknell.edu
Brian McInerney, Thesis student, cell 847-997-3218, bmcinern@bucknell.edu.

We seek experienced small-stream brook trout anglers to sample for brook trout by hook-and-line for one or more days during the period June 1-14, 2005. A summary of the project is at the bottom of this page.

Description of volunteer qualifications and fish sampling methods (.pdf file)

List of stream names, counties, USGS 7.5" topo quadrangles, and PA Gazetteer page (.xls file or .pdf file)

More details on sample locations will be provided once anglers have chosen streams that they are willing to sample.

Please contact us if you wish to participate. Thanks.

Figure 1. Extent of Tuscarora formation (gray regions), Valley and Ridge Province, Pennsylvania. There are a few study streams in Schuykill and Berks County near Hawk Mountain.

Proposal Summary: Pennsylvania has some of the lowest pH rainwater in the US due to acid deposition. Within the Valley and Ridge geologic Province, the Tuscarora, Juniata, and Bald Eagle Formations form most of the ridges and host most of the headwater streams. 645 streams (248 miles) originate in the Tuscarora (or the equivalent Shawangunk) Formation, a remarkably pure quartz sandstone containing few other mineral constituents that can buffer acidity. Preliminary research by Turner (2003) and Kirby and Turner (2005) shows the following.

All but two of 34 sampled streams that 1) originate in the Tuscarora, and 2) have not received water from tributaries originating in other formations have 4 < pH < 6 and are acidified or at high risk of being acidified. Juniata and Bald Eagle streams flowing into Tuscarora streams can add enough alkalinity to allow for pH recovery and for brook trout to thrive. Limestone gravel roads (if parallel to streams) appear to increase stream pH.

13% of Tuscarora streams (≈ 31 stream miles) are officially listed as “impaired” due to atmospheric deposition and low pH but the Pennsylvania DEP. We hypothesize that ≈ 60 to 80% (150 to 200 stream miles) of streams that originate in and flow through the Tuscarora Formation without receiving waters from other formations are acidified due to acid deposition and should be re-evaluated to determine if they are currently impaired This project will test this hypothesis based on sampling a subset of streams, complete a GIS coverage, and share the results with the scientific and regulatory communities as well as citizens’ groups.

A more complete proposal (.pdf file) can be downloaded.

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