Targus was retained to perform an environmental site assessment (Phase I ESA and additional non-ASTM services) of a five-story multifamily apartment building with ground floor retail and restaurant tenants and a two-story subterranean parking garage. The improvements were completed in 2015. The property was located within an area historically occupied by the Denver, Utah, and Pacific Railroad Depot yard, the Kimball Red Sand Stone Company Yard, and the Rocky Mountain Fuel Company. Black coal-like fill was present in the subject property area. A Voluntary Cleanup Plan (VCUP) for the area was prepared by others in August 2000 and submitted to the Colorado Department of Public Health and the Environment (CDPHE).
In November 2013, a Petition for No Action Determination (NAD) was prepared for the subject property. The report documented remedial activities including the excavation, loading, and disposal of the impacted black coal-like fill. Additionally, petroleum contaminated soil was encountered during excavation activities in the vicinity of a historical UST, and petroleum contaminated soil was removed from the subject property and disposed off-site. Response action included covering of the remaining impacted soil outside of the building envelope with a minimum three inches of cement to isolate the soil from direct contact.
Groundwater analyzed on the subject property met the CDPHE Basic Standards for Groundwater, with the exception of naturally-occurring dissolved manganese and iron. The CDPHE issued an Approval of NAD Petition Letter for the subject property and stated that the Petition indicated no evidence of remaining contamination released into the environment that posed an unacceptable risk to human health or the environment, and confirmed that groundwater contamination present beneath the subject property was from an up-gradient source for which the applicant was not responsible. Based on the NAD letter, Targus considered the known on-site coal-based fill materials encapsulated beneath the cement cover and elevated concentrations of dissolved manganese and iron in groundwater to collectively be a controlled recognized environmental condition.