HR: 09:33h
AN: H41K-07    [Abstracts]
TI: Perchlorate in Turfgrass Systems, Suffolk County, Long Island, NY
AU: * Munster, J E
EM: jmunster@notes2.cc.sunysb.edu
AF: Stony Brook University, Geosciences Dept., Stony Brook, NY 11794, United States
AU: Hanson, G N
EM: Gilbert.Hanson@stonybrook.edu
AF: Stony Brook University, Geosciences Dept., Stony Brook, NY 11794, United States
AU: Jackson, W A
EM: andrew.jackson@ttu.edu
AF: Texas Tech. University, Dept. of Civil and Environmental Engineering, Lubbock, TX 79409, United States
AB: Perchlorate concentrations in precipitation, grass clippings, and soil water were analyzed at nine turfgrass sites in Suffolk County, NY. The samples were collected monthly between June, 2006 and January, 2007. The soil water was collected from suction lysimeters at 100 cm depth. Four of these sites were treated with chemical fertilizer, three with organic fertilizer and two were not fertilized. Concentrations of ClO₄ in grass clippings and soil water, at the sites treated with chemical fertilizer or not treated with fertilizer, are found to increase when spikes of ClO₄ concentrations in precipitation are observed. We believe that the spikes in perchlorate in precipitation collected shortly after the Fourth of July are due to firework displays. The concentration of ClO₄ in soil water are 1 to 3 times higher than the maximum perchlorate concentrations in precipitation, with maximum soil water concentrations ranging from 0.5 to 3.0 ppb. At the sites treated with organic fertilizer, grass clippings and soil water ClO₄ concentrations increase after the fertilizer application in May. The organic fertilizer that was applied has nine mg ClO₄ per kg (9,000 ppb). Soil water concentrations at the sites treated with organic fertilizer increase 100 to 300 times the maximum ClO₄ concentration observed in precipitation, with maximum soil water concentrations ranging from 120 to 625 ppb. The increase in ClO₄ concentrations in the soil water cannot be explained by evaporation alone since the Cl to ClO₄ ratios decrease in the soil water relative to precipitation. This decrease in the Cl to ClO₄ ratio suggests another source of perchlorate besides precipitation. We postulate that this additional source is associated with the decomposition of mulched grass left after mowing. Grass takes only a few weeks to decompose after mulching, thus providing a continuous source of perchlorate throughout the mowing season. The Cl to ClO₄ ratio of the grass is unknown.
DE: 0496 Water quality
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1854 Precipitation (3354)
SC: Hydrology [H]
MN: 2007 Fall Meeting