Case Study of Groundwater Contamination at the Delphi Corporation, Wyoming, Michigan Dr. Peter E. Riemersma Department of Geology Grand Valley State University Allendale, Michigan Geohydrology (Geo 440), 3 credit, no lab, elective, undergraduate Allendale

Project Overview Individual Jigsaw/Synthesis Analysis Figures/Maps ConceptsProcesses XS WT CPL XS WT CPL XS WT CPL XS WT CPL XS = Geologic cross-section WT = Water table map CPL = contaminant plume map

Project Objectives Answer basic hydrogeological questions : What is the subsurface geology,? What is the direction of groundwater flow? What is the distribution of contaminants in the groundwater? Gain valuable skills in: Contouring data and correlating lithologic units Making interpretations and interpolations with sparse data Attitudinal Goals Appreciation for uncertainty, non unique solutions, interpretations Get a feel for the “art” in the science. Gain confidence.

Importance “someone got paid to do this” Yes it is! AGI 2009

The Delphi Site is of Public Interest and Local Concern – Media Coverage! Wood TV May 2009 "That fear is always there," said Doug Rozema, who lives in the shadow of the Wyoming Delphi plant.

Delphi Grand River Introduction

Delphi

Timeline of Events Delphi Corp. auto-parts plant 1946 Factory built at site of agricultural fields 1986: 2,000-gallon TCE underground storage tank removed : Monitoring wells installed around tank site, pump and treat 9.6 million gallons of groundwater a year. 1993: EPA calls leak an "area of concern." November 2002: First wells drilled away from tank to check for spread. June 2003: High levels of vinyl chloride found in new wells at north end of plant. October 2003: Neighbors notified that groundwater is contaminated. April 2005: Kent County judge approves class-action status. June 2006 Class action suit settlement of 1.2 million dollars

Examples: RCRA Facility Investigation Work Plan, Haley and Aldrich, April 2003 Field Event #3 Data Summary Package, Haley and Aldrich, February 2005 Wyoming Branch Library Sometimes its surprising what you can find at your local library! Data includes: 94 wells! (including 14 well nests) Water levels measured on different dates 20 times in 2003 – 2005 Wells analyzed for metals and analyzed on 4 – 6 occasions for VOCs

Lithologic Description Geologic Cross -Sections

A’A’ A 800 feet Blue Sand/Gravel Brown Clay Red Bedrock

Jan 2005 Groundwater flow to the north (Grand River) Changes in aquifer thickness affect the hydraulic gradient Pump and Treat System

Some seasonal changes in water table observed Ask students to explain why a change?

MW 206 Under plant floor Total VOCs Aug 2004 LNAPL

Dehalogenation of TCE TCE cis 1,2-DCE VC

VC Criteria: Resid DW 2 ppb Vinyl Chloride DCE Homeowner concerns Aug 2004

Example Analysis Questions 1. Identify and describe a channel and identify the approximate orientation of the channel axis. 2. List at least two potential “explanations” and causes for the higher hydraulic gradient near MW 202 in the Delphi water table map. Which is the more reasonable explanation? 3. What is the likely origin of the DCE and vinyl chloride in the groundwater and why are the concentrations of TCE in general lower at the site?

Why this Project? Public impact and history (story to tell) Large dataset, quality reports and consultant Common contaminant (TCE) and breakdown products Flexible (and different) student assignments Interesting hydrogeological conditions Accessible reports (provided)

How consultants showed chemical data at the site!

Wyoming Environmental Services Supervisor Myron Erickson said engineers for the company and state likely believed they were pumping out and treating enough groundwater in the 1980s and 1990s to keep the contamination from spreading. "They either miscalculated or didn't have enough data to begin with," Erickson said. "Groundwater is tricky because you can't see it.