Publication Summary

This is the study plan for the Bertrand Creek and Meadowdale Areas (Whatcom County) Follow-Up Study of EDB and 1,2-DCP in Residential Wells.

Ethylene dibromide (EDB) and 1,2-dichloropropane (1,2-DCP) are soil fumigants that are present in groundwater in northeastern Whatcom County. The Sumas-Blaine aquifer is the primary source of drinking water in the area. Groundwater was initially discovered to be contaminated in 1984 during a statewide investigation. Alternate water sources were supplied to those residents where contamination was documented or suspected. A more comprehensive study was conducted in 1998 which focused on drinking water from 123 private domestic wells in the Bertrand Creek and Meadowdale areas near the city of Lynden, Washington. The purpose was to refine the nature and extent of EDB and 1,2-DCP contamination in groundwater and determine the fate and transport mechanisms.

This is a follow-up study that will define the current condition of the aquifer and it is designed to supplement the existing data collected in 1998 by O′Herron. This is a one-time sampling project that will target approximately 30 private domestic wells. A subset of the wells previously sampled in 1998 will be resampled in this study, plus additional wells which have never been sampled before. The goal of this project is to: (1) update previous findings to provide a current picture of the contaminant levels, (2) determine the extent of the contaminant plumes, (3) determine the natural attenuation rate of EDB and 1,2-DCP concentrations in the area, and (4) verify the adequacy of the supplemental drinking water program.

Link to EIM data for User Study ID mkim0001