Soil and Water

Soil and Water

Soil Sampling

Prior to construction start, the Central 70 team collected soil samples for testing to determine if and how soil can be reused. The team collected more than 1,800 samples along the 10-mile corridor. Soils fall into one of the three categories below depending on content.

Download the full corridor diagram

  • Unrestricted reuse: This is normal soil that can be reused on the Project for things like backfilling for embankments and roadway.
  • Restricted reuse: This soil will be used east of Colorado Boulevard. The material will be used in accordance with the restrictions set by the Colorado Department of Public Health and Environment (CDPHE) and the Colorado Department of Transportation (CDOT).
  • Disposable: This soil is removed and hauled off site to a certified disposal facility.

The Project team is currently compiling results from the remainder of the soil samples but so far, 87 percent of the soil samples came back as “unrestricted reuse”. Eleven percent of the samples came back as “restricted reuse.” Finally, two percent of the samples came back as “disposal.”

For the soils that were determined to be red or yellow, the percentages of each material found in these samples are shown below. As you can see, a majority was Benzo(a)pyrene - a compound that can be found in coal tar and automobile exhaust fumes. Arsenic is a naturally occurring element in Colorado.



  • How are we avoiding it? The profile of the lowered section is above the groundwater table.
  • What do we do with it if we come across it? Water will be pumped into onsite tanks. This water will be transported to a permitted water treatment facility where it is treated.
  • How do we test it? Water is taken by the water treatment facility for treatment.

Asbestos Soil Remediation

Prior to buildings being removed, a survey for asbestos is performed inside and outside of the structure. If asbestos is found on the structure, an abatement plan will be developed and an abatement permit will be issued by the Colorado Department of Public Health and Environment (CDPHE). Asbestos abatement is performed by licensed contractors and Colorado state-certified asbestos building inspectors. Building Inspectors are onsite to ensure the removal is completed in accordance with the permit and abatement plan. Air monitoring will also be performed during the asbestos abatement activities. Site Surveys

Colorado: The Official State Web Portal