Weston Solutions, Inc. 1400 WESTON Way West Chester, PA 19380 610-701-3000 Fax 610-701-3186 www.westonsolutions.com 26 March 2014 U.S. Environmental Protection Agency Region III Attn: Mr. Eugene Dennis On-Scene Coordinatoro 1650 Arch Street Philadelphia, Pennsylvania 19103 Subject: Final Trip Report – Geophysical Investigation Project: Dwyer Property Groundwater Superfund Site EPA Contract No.: EP-S3-10-05 TDD No.: WS01-11-08-001 Document Control No.: W0075.1A.008779 Dear Mr. Dennis: Weston Solutions, Inc. (WESTON®) is submitting the final Trip Report for the geophysical investigation conducted at the Dwyer Property Groundwater Supeerfund Site (Site). Thiss Trip Report summarizes field activities, results, conclusions, and recommendations of the investigation. If you have any questions regarding this reeport, please call me at (610) 701-3191. Sincerely, WESTON SOLUTIONS, INC, Projject Task Lead Enclosure cc: TDD File (Weston – START POC) AR100274 FINAL TRIP REPORT GEOPHYSICAL INVESTIGATION DWYER PROPERTY GROUNDWATER SUPERFUND SITE ELKTON, CECIL COUNTY, MARYLAND EPA CONTRACT NO.: EP-S3-10-05 TECHNICAL DIRECTION DOCUMENT NO.: WS01-11-08-001 DOCUMENT CONTROL NO.: W0075.1A.00879 Prepared For: U.S. ENVIRONMENTAL PROTECTION AGENCY REGION III HAZARDOUS SITE CLEANUP DIVISION 1650 ARCH STREET PHILADELPHIA, PENNSYLVANIA 19103 Prrepared By WESTON SOLUTIONS, INC. 1400 WESTON WAY WEST CHESTER, PA 19380 WESTON PROJECT NO.: 20403.012.001.0075.00 MARCH 2014 AR100275 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report - Geophysical Investigation FINAL TRIP REPORT GEOPHYSICAL INVESTIGATION DWYER PROPERTY GROUNDWATER SUPERFUND SITE ELKTON, CECIL COUNTY, MARYLAND 3/26/2014 WESTON - Project Task Lead Date 3/26/2014 WESTON - Project Geophysicist Date 3/26/2014 WESTON - Project Work Scope Manager Date AR100276 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report – Geophysical Investigation TABLE OF CONTENTS Section Page 1.0 INTRODUCTION..............................................................................................................1 2.0 BACKGROUND ................................................................................................................2 2.1 SITE LOCATION ....................................................................................................2 2.2 SITE DESCRIPTION ..............................................................................................2 2.3 SITE HISTORY .......................................................................................................2 2.4 PREVIOUS INVESTIGATIONS ............................................................................3 3.0 SITE ACTIVITIES ............................................................................................................5 3.1 UXO AVOIDANCE ................................................................................................5 3.2 GEOPHYSICAL SURVEY .....................................................................................6 3.3 ELECTROMAGNETIC (EM) TERRAIN CONDUCTIVITY SURVEYING METHOD ........................................................................................6 3.3.1 Description ................................................................................................6 3.3.2 Methodology .............................................................................................7 3.3.3 Data Analyses ...........................................................................................7 4.0 INVESTIGATION RESULTS ..........................................................................................8 4.1 UXO AVOIDANCE RESULTS ..............................................................................8 4.2 EM RESULTS .........................................................................................................8 4.2.1 Area of Investigation Results ....................................................................8 5.0 CONCLUSIONS AND RECOMMENDATIONS ...........................................................9 6.0 REFERENCES .................................................................................................................10 ii AR100277 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report – Geophysical Investigation APPENDIX A LIST OF FIGURES Figure 1: Site Map – Geophysical Investigation Area Figure 2: Site Layout Map Figure 3: Area of Investigation Figure 4: Electromagnetic Survey – EM31 Inphase Plot Figure 5: Electromagnetic Survey – EM31 Conductivity Plot APPENDIX B LIST OF TABLES Table 1: Summary of GPS Coordinates for Individual Anomaly Locations Table 2: Summary of GPS Waypoint Coordinates for Bulk Anomaly Boundary iii AR100278 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report – Geophysical Investigation 1.0 INTRODUCTION Under the Eastern Area Superfund Technical Assessment and Response Team Contract No. EP- S3-10-05, Technical Direction Document No. WS01-11-08-001, the U.S. Environmental Protection Agency (EPA) Region III tasked Weston Solutions, Inc. (WESTON®) to perform a non-intrusive Geophysical Investigation at the Dwyer Property Groundwater Superfund Site (Site) in Elkton, Cecil County, Maryland. The purpose of the investigation was to conduct UXO avoidance and surface anomaly investigation at the Former Dump Area. In addition, to provide subsurface information necessary to characterize the potential for buried materials identified in and around suspected disposal pits and trenches associated with the Former Dump Area. The primary objectives were to; 1) Map and attempt identify the footprint (lateral extent and boundary) of the suspected fill; and, 2) Locate and map subsurface anomalies (targets) potentially containing disposal materials (i.e. metallic debris, drums and other facility waste). The investigation was performed on an approximate 1.13 acre portion of the Site; the Area of Investigation (AOI). The AOI encompasses the Former Dump Area, as defined by a map provided by Maryland Department of the Environment (MDE) personnel familiar with the Site. According to MDE personnel, the Former Dump Area is suspected to contain buried Unexploded Ordnance (UXO) and/or munitions. The AOI and Former Dump Area are depicted on Figure 3, Geophysical Area of Investigation, Appendix A. Field activities consisted of UXO surface avoidance to identify and mark surficial metallic objects within the investigation area. In addition, WESTON performed an electromagnetic survey of the subsurface using a Geonics Electromagnetic Terrain conductivity meter (EM-31). This trip report presents Site background information in Section 2.0; summarizes field activities, geophysical instrumentation and methodology in Section 3.0; summarizes the electromagnetic survey results in Section 4.0; and, presents conclusions and recommendations in Section 5.0. All 1 AR100279 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report – Geophysical Investigation references cited in this Trip Report are listed in Section 6.0. Figures are provided in Appendix A. Tables are provided in Appendix B. 2.0 BACKGROUND This section describes the Site location, presents a description of the Site, discusses the Site history, and describes previous investigations conducted at the Site. 2.1 SITE LOCATION The Site is located within the city of Elkton, in Cecil County, Maryland, as shown in Figure 1, Site Location Map, Appendix A. The Site is located immediately northeast of the intersection of Maryland Route 545/Blue Ball Road and Maryland Route 279/Newark Avenue. The total area of the Site is approximately 73 acres. The geographic coordinates of the approximate center of the Site are 39.61648° north latitude and 75.84404° west longitude. 2.2 SITE DESCRIPTION The majority of the Site is undeveloped land, either as forest or open fields. Land use adjacent to the Site is undeveloped to the north, with residential and commercial beyond; residential and commercial to the east; commercial, industrial, and agricultural to the south; and industrial to the west. Dogwood Run flows to the southwest along the western portion of the Site into Little Elk Creek. The Rudy Park Public Housing Project and associated recreational area (playground) are located adjacent to the southeast of the Site. Maryland Route 279/ Newark Ave borders the Site to the south. Maryland Route 545/Blue Ball Road borders the Site to the west. The Site and adjacent properties are depicted in Figure 2, Site Layout Map, Appendix A. 2.3 SITE HISTORY The Site was used for agricultural purposes prior to 1933. In 1933, the Site was purchased by Triumph Fuse and Fireworks Company and used to produce signal flares, fireworks, and various munitions and trinitrotoluene-based explosives (MDE fact sheet). Materials used at this plant included powdered metals, perchlorate, chlorate mixes, barium nitrate, charcoal, sulfur, sulfur 2 AR100280 Dwyer Property Groundwater Superfund Site Elkton, Cecil County, Maryland Final Trip Report – Geophysical Investigation mixes, saltpeter, carbon tetrachloride, hexachlorobenzene, alcohol, picric acid, stearine, dextrin, and potassium perchlorate). The munitions and explosives production continued through World War II as Triumph Fuse and Fireworks Company continued to service both the Army and Navy operations (EPA 2010). In 1946, the Bowers Battery and Spark Plug Company purchased the Site and used the land to manufacture