This dataset contains a comparison of chemical analysis results obtained by the U.S. Geological Survey (USGS) New York Water Science Center Soil and Low-Ionic Strength Water Quality Laboratory and the Adirondack Lake Survey Corporation (ALSC) Laboratory. Duplicate samples were collected biweekly from Buck Creek and the North and South Tributaries of Buck Creek from September 5, 2006, through September 2, 2008, to be analyzed in each laboratory. The 155 pairs of samples collected over 2 years enabled comparisons to be made under a variety of flows and seasons, using the markedly different chemical characteristics of the three streams. An additional 6 duplicate samples collected in 2016-2017 from Buck Creek were analyzed in each laboratory [...]