Sewer System Infrastructure and Stressors on Water Quality in Streams within the Alplaus Watershed in Upstate NY

Healthy aquatic ecosystems require clean water, but many creeks and streams may be impaired by human activity. This study is focused on surface water quality of the Alplaus, and Indian Kill streams located within the Alplaus Watershed in Schenectady and Saratoga Counties (NY). The primary goal of this study is to understand the extent of water quality impairment within the Alplaus and Indian Kill using a range of indicators to understand the impacts of failing infrastructure and stressors to surface water. Sixty-five water samples were collected in the fall of 2021 from six locations in the Alplaus and Indian Kill and they were taken during periods of low- and high-flow. Samples were measured for fecal indicator bacteria (FIB) Enterococcus, dissolved ions, and physical water quality parameters. At high flow, samples show elevated levels of FIB and Phosphate. Single sample Enterococcus levels exceeded the EPA Beach Advisory Value (BAV = 60 mpn/100 mL) in 93% of samples (61/65) from both low- and high-flow conditions. The geometric means at low flow for the Alplaus and Indian Kill are 180 and 100 mpn/100 mL, respectively. The geometric means at high flow for the Alplaus and Indian Kill are 14,652 and 21,291 mpn/100 mL, respectively. The two highest recorded Enterococcus values were after periods of high rainfall along the Mayfair Creek, a tributary to the Indian Kill in an urban setting. During low flow (or baseflow) high levels of nitrate, sodium, and chloride indicates input from contaminated groundwater, especially in the suburban/urban setting of the Mayfair area in the town of Glenville (Indian Kill). The Alplaus and Indian Kill streams are fed by groundwater discharge during low flow, indicating there is contamination of the groundwater. Low flow concentrations of chloride and nitrate were three and four times higher than high flow in the Alplaus Watershed respectively. Through increased urbanization and aging infrastructure, it appears that surface water quality in streams and rivers has been impaired by sewage from leaky pipes or failing septic systems and chemical pollutants such as road salt. Local areas with chronic contamination have a large number of septic systems, most presumably 60–70-year-old, and are a likely suspect of water quality impairment to groundwater that is especially apparent in the Indian Kill