Open-File Report 81-1115 "An evaluation of water-quality monitoring in the Brandywine Creek Basin, Pennsylvania, 1973-78" by J.J. Murphy, J.R. Ritter, A.E. Brown, and J.P. Chiarella       Data recorded from 1973 through 1978 by monitors on West Branch Brandywine Creek at Modena, East Branch Brandywine Creek below Downingtown, and Brandywine Creek at Chadds Ford were analyzed to evaluate the effectiveness of the monitors in describing water-quality conditions. The data show that the stream at Modena and below Downingtown had periods of low dissolved oxygen, and that the stream below Downingtown had a particularly severe dissolved-oxygen deficiency from May through September 1974. The pH at all three sites exceeded 9.0 at times and the pH below Downingtown occasionally dropped below 6.0. The most critical period in the basin was from March to November when pH was most likely to exceed water-quality standards and dissolved oxygen was most likely to fall below the standards. Without the monitors, the extent and magnitude of these problems would not have been detected. Return to the Water Resources of Pennsylvania Home Page or go directly to: The URL for this page is http://pa.water.usgs.gov /abstracts/ofr_81-1115.html Please note our privacy statement and disclaimer Accessibility Answers to many common questions can be found on our Frequently Asked Questions (FAQ) page. Please direct content comments or questions to: Information Specialist U.S. Geological Survey 215 Limekiln Road New Cumberland, PA 17070-2424 Phone: (717) 730-6916 FAX: (717) 730-6997 Email: is_pa@usgs.gov or contact: Director, USGS Pennsylvania Water Science Center U.S. Geological Survey 215 Limekiln Road New Cumberland, PA 17070-2424 Phone: (717) 730-6960 FAX: (717) 730-6997 Email: dc_pa@usgs.gov Please direct web related comments to webmaster@pa.water.usgs.gov caww52