Approximating Pollutant Transport to Ground Water^a

Abstract

Three simplistic models are developed for evaluating the transport of organic pollutants through soil to ground water. The models consider mobility and first‐order degradation. The first calculates linear sorption/desorption of the pollutant and first‐order degradation without considering dispersion. The second is similar to the first but also considers dispersion. The third considers nonlinear sorption following a Freundlich equation and first‐order degradation but does not consider dispersion. The models are compared to field data for the pesticides aldicarb and DDT. The models projected a lower mobility for DDT than was observed in the field.

Use of geographic information systems for assessing groundwater pollution potential by pesticides in Central Thailand

“…Examples include Chemical, Runoff, and Erosion from Agricultural Management Systems (CREAMS) (Knisel, 1980), Groundwater Loading Effects of Agricultural Management Systems (GLEAMS) (Leonard et al, 1990), Leaching Model for Pesticides (LEACHMP) (Wagenet and Hutson, 1986), and Pesticide Analytical Model (PESTAN) (Enfield et al, 1982). However, these models are most useful only at local scales; required data elements generally are not available at regional scales.…”

“…These include the DRASTIC model (Aller et al, 1987), pesticide root zone model (PRZM) (Carsel et al, 1985), vulnerability to pesticides model (VULPEST) (Villeneuve et al, 1990), leaching potential index (LPI) (Meeks and Dean, 1990), attenuation factor (AF) (Rao et al, 1985), and pesticide analytical model (PESTAN) (Enfield et al, 1982). However, this study proposes to use geographic information systems (GIS) technology to assess groundwater pollution potential by pesticides in central Thailand.…”

“…Carsel and others (1985) developed this model in order to evaluate pesticide leaching potential under field crop conditions. There are many factors contributing to pesticide leaching, e.g., chemical solubility in water, pesticide formulation, soil properties, climate conditions, crop types, water management methods, and cropping practices (Enfield et al, 1982;Selim et al, 1977;Davidson et al, 1975).…”

Risk Assessment Issues Associated with Cleaning up Inactive Hazardous Waste Sites

“…This can be done through a variety of approaches ranging from a simplified steady-state soil-water partitioning model to time dependent models that consider linear adsorption/desorption without accounting for dispersion (Enfield et al 1982) or more complex compartmental numerical models that incorporate time-varying transport, advection and dispersion such as the Pesticide Root Zone Model (USEPA 1984). Applying these models to the same site may result in soil pore water concentrations that may vary by as much as several orders of magnitude.…”

Potential contamination of ground water by pesticides

“…Aldicarb metabolites were detected In the shallow ground water (at a depth of 1 to 2 m) in concentrations of 20-30 pg/L and in some instances even at levels of 50-400 pg/L (Ref. 8). …”