ASSESSING THE SOURCE AND FATE OF NITRATE IN GROUNDWATER ASSOCIATED WITH UPPER GLACIAL AQUIFER, SOUTH-EAST QUEENS, NEW YORK CITY

The Upper Glacial Aquifer (UGA) of Long Island, New York City, consists of a layer of stratified sediment, which underlies Kings, Queens and Nassau Counties. Previous withdrawal of water from this aquifer resulted in the encroachment of salt water and other contaminants into the aquifer, particularly along the coast. With the significant reduction of withdrawal from the aquifer, the water levels have recovered and now present a flood hazard. While nitrate is a common oxide of nitrogen due to the biochemical cycle of nitrogen, anthropogenic activities have a great influence on the nitrate concentration in groundwater. Groundwater nitrate concentration in urban areas, in some instances, can exceed the permissible limit proposed by the EPA (Environmental Protection Agency) and thus pose a threat to public health if the water is used for human consumption. Incidence of methemoglobinemia appears to be the result of high nitrate levels. Methemoglobinemia, or blue baby syndrome, robs the blood cells of their ability to carry oxygen. Due to the detrimental biological effects, treatment and prevention methods must be considered to protect groundwater aquifers from nitrate leaching and high concentrations. The proposed project aims to conduct a time series study to understand the nitrate and other ionic concentration in UGA in Queens Area. The study will generate the data from three existing USGS wells on the York College campus. A solinst levelogger depth sensor will be placed in one of the wells to collect water level data of the UGA. All three wells were installed in the UGA to an approximate depth of 50 ft below the surface. Groundwater samples from York College campus well be collected on a weekly basis and analyzed for nitrate (as NO 3 − ), nitrite (as NO 2 − ), Chloride (Cl-), phosphate (as PO4 3- ), sulfate (as SO 4 2− ), silica (as SiO₂ ) and ammonium (NH 4 + ), and other physical parameters including temperature, pH, conductivity, ORP, alkalinity and dissolved oxygen. York’s environmental laboratory is equipped with state-of-the art facilities and will be used to generate reliable data which will not only shed light on contamination, but also help inform the college and local community of the conditions. This data could be used as a baseline to help design the storm water management plan which is of great concern for residents in southeast Queens.