Redevelopment Area Brownfield Evaluation,

The Redevelopment Area encompasses approximately 100 acres, including a former aggregate mine operated from the early 1950s through 2001. The local city agency proposed to redevelop this property as a public park facility with grass fields, bike paths, nature trails, picnic areas, and a 15- to 20-acre lake that may also serve as a detention basin during heavy stormwater runoff. Prior to committing further resources to this project, environmental issues needed to be addressed relating to the documented regional and on-site presence of perchlorate in surface water and groundwater, and other possible contamination issues related to the former site use. The perchlorate source was believed to be two separate, up-gradient former ammonium perchlorate manufacturing plants; one operated by Kerr McGee and the other by PEPCON. In 1988, PEPCON had over 9 million pounds of ammonium perchlorate stored at the site when much of the product exploded, destroying the facility. Although surface/soil remediation at that site and at the Kerr McGee site had been addressed under USEPA Region 9 oversight, groundwater contamination from the operation of these facilities was still being investigated, and small scale/pilot study groundwater remediation technologies were being evaluated. Under our contract with the State Department of Environmental Protection, Ninyo & Moore performed a study of the proposed local city park site to identify possible soil and groundwater contamination issues relating to the site proximity to the Kerr McGee and PEPCON sites, and the prior operation of the site as a quarry. Of particular interest to the Department of Environmental Protection and the city was a lake and a small pond at the former quarry bottom, which are surface expressions of the regional groundwater table and which the city was hoping to incorporate as significant park recreational features. Our scope of services included a regional historical study (Phase I Environmental Site Assessment), including detailed reviews of Kerr McGee and PEPCON documents; preparation of a Sampling and Analysis Plan (SAP) for USEPA Region 9 and Dept. of Environmental Protection review and approval; drilling and sampling soil borings for site lithologic and chemical characterization; installation of groundwater monitoring wells to characterize hydrogeological and groundwater quality/contamination issues at the site; and conducting stratified surface water sampling to evaluate water quality/contamination issues.