Occurrence of 1,2-Dichloropropane and 1,3-Dichloropropene in the Abbotsford Aquifer, British Columbia

Abstract

Forty piezometers at 13 sites in the Canadian portion of the Abbotsford aquifer were tested for 1,2-dichloropropane (1,2-DCP) and 1,3-dichloropropene (1,3-DCP) on an approximate monthly interval from July 1991 to June 1994. Detectable levels of 1,2-DCP were found in 32 of the 40 piezometers. Average 1,2-DCP concentrations within a piezometer ranged up to 2.23 µg/L and a maximum concentration of 7.07 µg/L was recorded in one piezometer. 1,3-DCP was detected for only a short period of time in one piezometer and at a maximum concentration of 0.23 µg/L. 1,2-DCP contamination in the aquifer is attributed to application of fumigants containing this compound as an active ingredient or as an impurity for the control of root nematodes in red raspberry crops. The nature of the contamination is consistent with a non-point source that is highly variable in space and time. Although soil fumigants containing 1,2-DCP as an active ingredient are no longer used in the Abbotsford area, fairly constant values of 1,2-DCP would indicate there is still a contaminant source providing input to the groundwater. 1,2-DCP has apparently accumulated on the soil sediments above the water table and is slowly being released to the groundwater. In the top 15 m of the saturated zone, concentrations generally decreased with depth below the water table to near nondetectable levels. Correlation between contaminant levels and rainfall or other environmental factors that might affect the distribution of 1,2-DCP could not be established. More detailed soil measurements and controlled laboratory experiments are needed to determine 1,2-DCP movement as well as rates of dissipation in the Abbotsford aquifer.

Groundwater monitoring for 1,3‐dichloropropene in high fumigant use areas of North America and Europe

“…Grove et al conducted a groundwater monitoring study in an area of significant 1,3‐D use in the Abbotsford aquifer raspberry‐growing region of British Columbia, and sampled 35 wells for 1,3‐D on a monthly basis for 3 years (June 1991–June 1994). The wells were located in areas of the Abbotsford aquifer with high nitrate concentrations, and thus were suspected to be at most risk to the leaching of pesticides.…”

Fate and Origin of 1,2-Dichloropropane in an Unconfined Shallow Aquifer

“…While DCP-based fumigants are no longer used in the United States, sources of DCP still threaten groundwater quality. First, desorption of DCP derived from historical fumigant formulations may be responsible for the contamination of shallow groundwater (3). Second, while current 1,3-dichloropropene-(1,3-D) based fumigant formulations only contain trace amounts of DCP (<0.01 wt %), elevated concentrations of DCP have been observed in downgradient wells after applications of these products (4).…”