NUTRIENTS AND HEAVY METAL LOAD OF THE WATER IN URBAN LAKES AND PONDS OF QUEENS COUNTY IN NEW YORK CITY, USA

Most of the urban surface water bodies are under serious threats due to reckless recreational activities and contaminated water inflows. This study aims to investigate the water quality of several fresh water bodies in an urban setting. Seven ponds/lakes in Queens County, New York City were selected to cover wide ranges of urban settings and land-use patterns. The initial report covers the water quality of six different lakes/ponds. Water samples were collected from Meadow Lake (N40º 44.100' W73º 50.328'), Oakland Lake (N40º 45.527', W73º 45.468'), Kissena lake (N40º 44.880', W73º 48.360'), Bowne Pond (N40º 46.260', W73º 48.480'), West Ponds (N40º 37.080', W73º 49.860') and Baisely Ponds (N40º 40.100', W73º 47.000') to monitor physical and chemical parameters including pH, ORP, Temp., Conductivity, Salinity, Total dissolved solid, Dissolved oxygen, common anions (F^-, Cl^-, Br^-, NO₂^-, NO₃^-, PO₄^3- and SO₄^2-), NH₄⁺and a few heavy metals (Cu, Cd, Pb and Zn). YSI (model- 600QS-ORP-O) multi-probes instrument was used to monitor physical parameters on site. CHEMetrics self filling reagent ampules and V-2000 multi-analyte photometer were used to determine the nutrients and a few metals on site. The standard addition calibration curve was developed by spiking the reference standard to the sample matrix in the field. The final concentrations were obtained using the slope from this standard addition calibration curve with a r2 value of >0.997. Two sets of samples were collected from three or more locations in each pond/lake upon filtration through 0.45 μm membrane filters. Filtered-acidified and filtered samples were collected for trace metals and anions by CSV (Cathodic Stripping Voltammetry) and by Lachet FIA 8500 series II Nutrients analyzer coupled with Ion Chromatography (IC).

The preliminary data indicates that in slightly saline Meadow Lake and west ponds (conductivity 14627 μS/cm) water is relatively reducing with ammonia concentration of 3.22 mgL-1 while Oakland lake with conductivity (1086.67μS/cm) showed a higher level of nitrate concentration ( 3.0 mgL-1). Kissena lake and West pond showed significant amount of sulfate. The investigation is being continued in all lakes and ponds for total phosphate and chemical oxygen demand (COD).