Unexploded Ordnance Evaluation,
Former U.S. Army Site

Ninyo & Moore was retained to provide geophysical survey services and geophysical analysis for the evaluation of a 13 acre portion of a suspected unexploded ordnance (UXO) property. The U.S. Army used the site plus an additional 213 adjoining acres during World War II (WWII) as a munitions storage and transfer facility. The facility included approximately 37 berthing areas for railroad cars with 20 earthcovered bunkers adjacent to the berthing areas. A main line railway had several spur lines leading from the main railway to the berthing areas and to the bunkers. All U.S. munitions destined for the Chinese-Burmese-Indian theater during WWII passed through this facility on its way to loading onto transport ships. Over 3.5 million tons of explosives and ammunition were stored and/or shipped through the facility without accident. Following WWII, and from the mid-1950s to about 1993, private industry used portions of the area for the storage, manufacturing, assembling, and testing of a variety of explosives and pyrotechnic materials (fire-works). The site was also formerly used for storage, transfer, and open burn and open detonation (OB/OD) of hazardous wastes and high explosive materials. The OB/OD activities were conducted within an open earthen trench, approximately 20 feet below grade at its deepest point. At the request of our client, Ninyo & Moore developed and performed an evaluation plan utilizing both total field magnetometer and timedomain electromagnetic (EM) survey instruments in order to obtain measurements of EM and magnetic anomalies caused by buried metallic objects, including suspected UXO. In the case of the magnetometer survey, we collected magnetic data from nearly 10,000 measurement points along 18 linear miles of survey grid. In the case of the EM survey, we collected data from over 37 linear miles of survey grid. Our preliminary and final reports provided details of our method of survey, and our processed survey data. Our processed survey data maps indicated locations of a number of identified or suspected UXO, railway debris, former fence posts, metallic debris such as discarded propane canisters, known metallic surface features, and unknown buried metallic objects. In addition, our data and site evaluation revealed possible former dump areas, ash heap areas, and areas of former railway alignments. Our recommendations included field markout of suspected UXO items for inspection and possible disarming by the local county Sheriff's Department Bomb Squad. Following markout, we performed a site walk with the client to aid in their understanding of our survey results.