LAND USE AND THE IMPACT ON WATER QUALITY IN THE TOWNS OF GARDINER AND NEW PALTZ, ULSTER COUNTY, NEW YORK

Water resources in North America are increasingly susceptible to contamination from agricultural, suburban and urban point and non-point source contamination. Samples from surface water bodies were collected from 25 locations within the towns of Gardiner and New Paltz in Ulster County, New York. Concentrations of common water quality indicators were determined in the field and in the laboratory. These are pH, conductivity, dissolved oxygen, total iron, copper, hexavalent chromium, free chlorine, total chlorine, nitrate, nitrite, ammonia, phosphate, sulfate and sulfide. Initial land use information was obtained from the Ulster County tax parcel database, which contains more than twenty highly specific land use categories. However, three broad land-use categories were developed to encompass the more specific categories listed in the database. The new categories specified whether the land was developed, undeveloped, or used for agriculture. GIS analysis of water quality data with respect to land-use yielded inconclusive results. While other factors might be controlling the results, a standardized, quantitative method for describing land-use is needed in order to more precisely study its relationship to water quality. Future studies also will benefit from specification of a composite land use for individual sampling locations, particularly in sites where multiple land-uses are likely contributing to the local water quality.