WP21 Evaluation of Groundwater Communication with Surface Water and Contributions to Sediment Toxicity
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(RAB-1118-414517) GSI Criterion Development for Chloroethane - Predicted vs Measured Values.

Rabe, B¹, VanDellen, E², Susan, J³, ¹ Environmental Resources Management, Inc., Holland, MI, USA² Alticor, Inc., Ada, MI, USA³ Fishbeck, Thompson, Carr & Huber, Grand Rapids, MI, USA

ABSTRACT- As part of a RCRA Corrective Action remediation project involving the historical presence of chloroethane in groundwater venting to surface water, an environmentally acceptable limit for chloroethane needed to be established. With the lack of any established GSI criteria for chloroethane, the project team developed a method of estimating the toxicity from existing chloroethane molecules containing two, three, four, five, or six chlorine atoms. This method predicted an acute toxicity value of 249 mg/L. Needing additional support for regulatory acceptance, a Tier II Final Acute Value for chloroethane was generated using the waterflea (Daphnia magna) and fathead minnow. The results of the testing generated an acute LC50 of 322 mg/L for the waterflea and 266 mg/L for the fathead minnow. The results of the modeling method were found to be very similar to the actual Tier II values obtained from laboratory data.

Key words: chloroethane, Daphnia magna, fathead minnow