Open Innovation Challenges

Underground Infrastructure

Open Challenge: Cost-effective reduction and management of spoils from underground excavation

Underground Infrastructure
Deadline for concept summaries: September 16, 2022

Sponsored by

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Excavation methods used during the underground construction process generate excess spoils that must be properly treated and disposed of.  This is often a multi-step process in which spoils are transported to one facility for treatment prior to disposal at a second location.

Desired properties

  • Ability to treat spoils on-site or otherwise streamline disposal process and minimize cost
  • Minimize the volume of spoils created during the excavation process or generation of giveaway-ready spoils


Category 5: Spoils management

Problem statement

Undergrounding construction unavoidably disturbs soil at the site, generating excess spoils that must be properly disposed of. These spoils must be handled according to specific requirements and often must be hauled off-site for processing, remediation, or disposal. Moving soils back and forth for processing and disposal between off-site locations that are often far from dig sites requires time and resources that could be spent elsewhere. This process is particularly costly in cases where disturbed soil contains hazardous materials.

Possible approaches

Solutions of interest include those with the potential to facilitate on-site processing of excess spoils such as filtering debris or recycling water for wet spoils.  Novel construction methods that disturb less soil are also of interest, especially for use at sites where hazardous material is present, as well as methods that generate giveaway-ready spoils (i.e., additional processing is not required).

Industrywide Market GapPotential Solution Category
Existing excavation method generate
significant amounts of excess soils which
require processing and disposal
Methods to reduce amount of spoils generated

Methods that create spoils that require
minimal or no processing

Processing excess spoils occurs off-site,
incurring additional labor and
transportation costs to move large
volumes of debris from remote sites
Technology that enables on-site spoils processing
Known approaches not of interest
  • Procedural / management solutions are not of interest.
Key success criteria


  • Demonstrated improvement over current state-of-the-art technology
  • Ability to reduce the volume of spoils created during excavation by 35%
  • Demonstrated ability to process spoils in compliance with applicable regulatory standards



  • Commercially deployable within 3 years
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Labor required for digging tunnels and trenches, laying conduit and pulling and splicing cables drives the majority of undergrounding costs. While some innovation has been made in these areas, the methods and materials used have remained largely unchanged for years.


The existing process of obtaining the necessary permits, approvals and easements for undergrounding projects is burdensome and time-consuming. Depending on the specifics of the project, the permitting process may extend the overall timeline by over a year. The multi-step document preparation process, manual and iterative nature of stakeholder engagement and lack of standardization of design requirements across agencies and jurisdictions all contribute to the lengthy timelines. Given that all projects require some level of permitting, there is an urgent need to improve the process as benefits will be felt across the entire portfolio of work.