Client:
Neighborhood Services Organization
 
Location:
Detroit, Michigan

Prime Consultant:
NTH Consultants, Ltd.

Project Budget:
$500,000
 
Start Date:
February 2009

Completion Date:
December 2013
NSO Bell Building
Soil Gas Survey & Vapor Mitigation System

Award of Merit for Engineering:
American Council of Engineering Companies of Michigan (ACEC/Michigan)

The Neighborhood Services Organization (NSO) successfully converted the abandoned Michigan Bell Headquarters in the City of Detroit into a mixed use facility including apartments, offices, and clinic space. Initial environmental assessments identified a history of light industrial activities, underground tanks and the potential for contaminated soil gas to infiltrate into the building. When the initial consultant was not able to handle the technical challenges of the project, NSO turned to NTH for help turning this eyesore into an asset.

Project Scope
The project’s sponsor, the Michigan State Housing Development Authority (MSHDA), required that developer comply with the strict environmental requirements for investigation and remediation of the US Housing and Urban Development (HUD). NTH has a long history of successfully completing projects that are challenging from both a technical and regulatory perspective, and the NSO Bell Building is no different.

NTH provided the following services:

  • Conducted additional environmental investigations to properly characterize the site. Investigations included installing 27 soil gas wells and performing three rounds of soil gas sampling, installing and sampling 12 groundwater monitoring wells, and drilling/ collecting samples from over 50 soil borings.
  • Conducted site specific analysis to evaluate if building characteristics provided enhanced attenuation of soil vapors, using the results of the environmental investigation.
  • Designed and engineered a vapor mitigation system for the proposed building renovations. The system consisted of an active venting system with a supplemental membrane.
  • Designed a site remediation plan and engineered barrier to address soil impacts outside of the building. 
  • Prepared construction drawings and specifications for the engineered vapor mitigation system, the site remediation, and hazardous materials abatement.
  • Provided construction quality assurance services during installation of the vapor mitigation system, including documenting that the membrane was installed in accordance with the construction specifications.
  • Prepared a site Due Care Plan necessary for long-term site maintenance using the sampling results from the soil gas, soil, and groundwater sampling.
  • Obtained an approved Documentation of Due Care Compliance from the Michigan Department of Environmental Quality.