CHARACTERIZATION OF DISINFECTION BYPRODUCT FORMATION POTENTIAL WITHIN THE ASHOKAN WATERSHED: EFFECTS OF SOURCE MATERIALS

Disinfection byproducts (DBPs) are compounds that result from reactions between organic and inorganic matter in water with chemical treatment agents during the chlorination process. Some of these products, such as chloroform and haloacetic acids, are known to be toxic and are regulated with maximum contaminant levels for drinking water. The goal of this project was to understand the relationship between dissolved organic matter (DOM), sediment load, and local stream conditions and their DBP formation potential. Samples were collected throughout the Ashokan Reservoir watershed including the main stem of Esopus Creek, Warner and Stony Clove tributaries, local wetlands, and the inlet to the aqueduct leaving the reservoir. The unchlorinated samples were analyzed with a TOC analyzer to determine DOM concentrations, along with a Particle Size Analyzer to gain information on relative number and size of particles in the samples. The samples were then chlorinated, mimicking the water treatment, followed by analysis of disinfection byproducts. Samples from Warner and Stony Clove Creeks tended to have DBP levels higher than those along the main stem of Esopus Creek or at the reservoir. The sample with the highest concentration of DOM, sampled from a wetland, also had among the highest concentration of DBPs. However, DOM levels did not have a significant correlation to the number of particles in the water samples.