A GEOCHEMICAL AND SEDIMENTOLOGICAL SURVEY OF THE NORTHERN GATEWAY NRA, NEW YORK CITY, PART II

As a continuation of this two year project that was initiated on The Gateway National Recreational Area (NRA) in May of 2010, new geochemical data became available to the authors and provided opportunity for refining some of the previous work. The Northern sites that are adjacent to the Pennsylvania Ave and Fountain Ave Landfills were sampled, monitored, and analyzed for heavy metal loading last year. This year, the concentration of this study shifted to the southern sites that border the two landfills as well as the 26-Wards Waste Water Treatment Plant. The objective of changing the location is to cover all the surrounding parameters of a potential point source of heavy metal loading (if present) that have the capacity of contaminating the soil of one of New York's highly populated residential areas. Similar to the previously completed work on the northern sites, this new study location was subjected to the same standard methods of analysis thus facilitating the correlation between the two sites. Soil profilings were made up to 90 cm depth and samples were collected at 30 cm intervals. All samples were collected in low-tidal conditions and were preserved at 4^oC for further laboratory analysis. Current sedimentological data reveal higher percentage of finer sediment size with no specific trend. Furthermore, heavy mineral separation data illustrates a ~15% increase of heavy materials within four different sites that follow a uniform trend of depth 30-60 cm. Preliminary XRF results of the soil samples shows large spatial variation (50 to 150%) in Cl, K, Ca, Fe, and Mn with average concentration of 1.3%, 2.1%, 1.7%, 3.4%, 1297 mg/kg respectively. Further analysis will include grain mounted thin section to closely quantify the mineralogical composition of the sediment and correlation to the previously obtained data. There are no alarming signs of heavy metal contamination in the soil due to the nature of the XRF results where the obtained data falls below the USEPA standard limits of heavy metal concentration in soils.

Funded by US Dept. of Education (USDOE) Grant titled "Enhancing African American Students' Talents."