Publication Summary

This document is one in a series describing the results of long-term groundwater sampling at Lakewood/Plaza Cleaners. The Washington State Department of Ecology has conducted semi-annual groundwater sampling at the site since 1991. The objective of this sampling is to collect groundwater quality data for the Toxics Cleanup Program to evaluate the effectiveness of Lakewood supply wells H1 and H2 to contain and remove contaminated groundwater caused by Plaza Cleaners.

This document is one in a series describing the results of long-term groundwater sampling at Lakewood/Plaza Cleaners. The Washington State Department of Ecology has conducted semi-annual groundwater sampling at the site since 1991. The objective of this sampling is to collect groundwater quality data for the Toxics Cleanup Program to evaluate the effectiveness of Lakewood supply wells H1 and H2 to contain and remove contaminated groundwater caused by Plaza Cleaners.

On January 21, 1999 samples were collected from one municipal well (H1) and three monitoring wells: MW-20A, MW-20B, and MW-27. Well MW-16A, which is part of the long-term monitoring network, was not sampled due to failure of the dedicated pump. The pump was repaired prior to the August sampling. On August 2, 1999, samples were collected from one municipal well (H1) and seven monitoring wells: MW-16A, MW-19A, MW-20A, MW-20B, MW-27, MW-31, and MW-33. All samples were analyzed for volatile organics (VOAs).

Monitoring wells MW-20B and MW-16A, as well as municipal well H1, continue to have tetrachloroethene (PERC) concentrations that exceed the Model Toxic Control Act (MTCA) cleanup standard of 5.0 ug/L. PERC concentrations in these wells during the past year of sampling were MW-20B (708 ug/L and 722 ug/L), MW-16A (22 ug/L), and H1 (1.5 ug/L and 5.2 ug/L). Trichloroethene (TCE) was detected in MW-20B at concentrations of 5.2 ug/L and 8.4 ug/L, which also exceeds the MTCA cleanup standard for TCE of 5.0 ug/L. Cis-1,2-dichloroethene (cis-1,2-DCE) was detected in wells MW-20B (12 ug/L and 16 ug/L) and MW-16A (1.1 ug/L). Overall, concentrations are similar to those reported in previous sampling rounds.