Case Study

Remedial Design and Construction Management

Health & Safety Plan, Materials Testing Plan

Project Scope:

Engineering, design and construction services associated with the removal of 5,600 yd3 of radiologically-contaminated concrete and asphalt cover and the subsequent characterization of surface soils, subsurface soils and groundwater on a 6 acre site.


Process & Solution:

Initial preparation required a series of project work plans to guide characterization and response actions at the site.  These plans included a Stormwater Management Plan, Health & Safety Plan, Materials Transport Plan and Task Plan.  Our team subsequently met with CDPHE’s Laboratory and Radiation Services Division to negotiate disposal options for the concrete and asphalt based on both the ANSI surface screening level (6,000 dpm/100 cm2) and the ANSI volumetric standard (30 pCi/g).  Once the concrete and asphalt had been removed, a surface soil survey was conducted using a Global Positioning System (GPS) receiver connected to a survey meter to automatically store gamma radiation measurements at over 3,300 locations. Compliance with established cleanup standards was demonstrated in accordance with requirements outlined in the Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM).  Soil samples were collected at potentially impacted areas and subsequently analyzed for uranium, radium, thorium, and 11 metals.  Thirty-six trenches / test pits and 28 borings were used to investigate subsurface soils.  The subsurface investigation primarily focused on areas where drains or pipelines had penetrated concrete and asphalt slabs and in areas exhibiting elevated surface gamma readings.  A limited groundwater investigation was also conducted by Cascade’s personnel.  At the conclusion of the project a Characterization Survey Report was prepared and submitted to CDPHE.