Wood Hollow MRS

The 367-acre Wood Hollow Training Area (Wood Hollow) Munitions Response Site (MRS) is located along the northeastern boundary of Camp Williams. The MRS comprises privately owned land parcels located adjacent to an ongoing rock mining operation—the Beef Hollow Quarry—operated by the Staker-Parson company (no relation to Parsons). Residential development of the Wood Hollow area has begun. The lands surrounding the immediate area have been annexed by the City of Herriman, Utah. The MRS is characterized by steep, rock-strewn hills covered mainly with grasses and minor sage, with large dispersed thickets of oak brush (Gambel Oak) throughout. The remedial investigation (RI) completed by Parsons shows that the Wood Hollow MRS was the location of a historical artillery target area. Based on the predominance of shrapnel-type 75mm projectiles and related munitions debris (MD) found at the site, it is believed the site dates to around the decade following World War 1. In addition to 75mm shrapnel munitions, minor amounts of 75mm high explosive (HE) and 37mm projectiles, as well as MD related to these munitions, have been found at the site, consistent with post-World War 1 history for the site. During that historical time it was common for artillery units to affix 37mm gun tubes to 75mm howitzers in order to train while saving on ammunition costs.

Initially, the Wood Hollow MRS was a much smaller site (78 acres). The MRS was expanded based on the results of successive investigations. In 2011, a time-critical removal action (TCRA) was performed to remove surface and subsurface munitions over 31 acres of the site where a mining haul road was planned. Findings of the TCRA were consistent with results of the RI, showing the site contained remnant 75mm and 37mm projectiles and MD at the shallow surface level. For this reason, the remedial action (RA) required for Wood Hollow included a surface and subsurface munitions and explosives of concern (MEC)/MD removal action that was completed in 2017. The MRS is partially covered in dense thickets of oak brush. In order to conduct geophysical investigations for subsurface MEC/MD removal, approximately 74 acres of oak brush was cut from the Wood Hollow MRS.

Transect investigations were conducted in unremediated areas outside of the Wood Hollow MRS. Data collected along transects was used to verify that the extent of the Wood Hollow MRS was adequately defined and to confirm that risk-based thresholds established under the statistical approach for areas adjacent to the MRS were not exceeded. No MEC was found outside the Wood Hollow MRS, and only scattered limited MD was found outside the MRS. The entire study area encompassing the Wood Hollow MRS and the adjacent area of transect investigation was designated as the Wood Hollow Munitions Response Area (MRA). At the conclusion of the RA, the area of transect investigation outside the original Wood Hollow MRS was subdivided into two additional MRSs: the Central Area MRS, where only scattered MD was found and a low density of artillery-related MD is anticipated based on Visual Sample Plan (VSP) modeling; and the outlying Western Area MRS, where no artillery-related MD was found.

Online Repository

For additional information and reports of previous investigations, please visit the Repository