ENVIRONMENTAL DUE DILIGENCE


ERO’s experience with agricultural, urban, and industrial sites allows us to bring our practical knowledge to site assessment, characterization, and remediation activities. Using innovative, yet appropriate, technologies, we specialize in cost-effective solutions to address our clients’ site-specific challenges. Our understanding of the most current federal, state, and local environmental regulations and policies allows us to assist clients with regulatory compliance, due diligence assessment, and project-oriented environmental support.


  • Phase I environmental site assessment
  • Petroleum storage tank closure
  • Phase II site characterization
  • Voluntary cleanup plan
  • Waste management assistance
  • Phase III site remediation
  • CERCLA environmental decommissioning

Areas of Expertise

Phase I environmental site assessments

ERO has completed hundreds of high-quality Phase I environmental site assessments throughout the West that meet or exceed American Society for Testing and Materials guidelines.  We work on properties ranging from undeveloped agricultural parcels, to complex urban and industrial lots, to road and pipeline corridors.  From sensitive real estate transactions to regulatory compliance, small property owners to government agencies, ERO provides clients with comprehensive, coherent assessments that have resulted in a growing list of loyal customers who depend on our expertise. Our geologists and environmental scientists conduct:

  • Field inspections of the property
  • Interviews with clients, property owners, and government officials
  • Searches of federal, state, and local environmental records
  • Reviews of historical maps, records, and aerial photography

Phase II site characterizations

If a Phase I environmental site assessment identifies a recognized environmental condition on a property, ERO has the technical expertise to efficiently conduct a Phase II site investigation.  We have conducted numerous site investigations to characterize and delineate potential soil and groundwater contamination at a variety of properties from service stations, dry cleaners, and oil and gas wells to industrial plating shops and manufacturing facilities. These site investigations include:

  • Detailed soil core logging and sampling
  • Groundwater and soil vapor well installation and sampling
  • Interior and limited access drilling
  • Indoor air quality assessments

Phase III site remediation

ERO has designed and operated numerous site remediation systems using standard and innovative approaches tailored to cost effectively return contaminated properties to full use and value. Where appropriate for hydrogeologic conditions, ERO staff has used industry standard technologies, such as pump and treat. In other instances, we have developed and used techniques such as geochemical barriers to stop off-site migration of contaminants, treated the groundwater directly with in situ chemical oxidation, and have overseen large-scale excavations to remove the source area.

Groundwater modeling

ERO’s modeling capabilities include digital and analytical groundwater flow, capture zone, contaminant transport, and surface water quality modeling. Our hydrologists use models to assist clients by:

  • Expediting closure of contaminated sites
  • Designing groundwater remediation and control systems
  • Estimating cleanup time for contaminated sites
  • Determining the impact of surface water diversions and dams on downstream flow volumes and water quality
  • Estimating the impact of groundwater pumping on nearby wells and streams
  • Evaluating potential impacts on groundwater and surface water due to proposed projects

Petroleum storage tank closures

ERO has been working on underground storage tank sites since 1987, prior to their regulation.  Our broad range of services for owners and operators of petroleum storage tanks include:

  • Preparing health and safety plans
  • Overseeing tank removals
  • Coordinating emergency response in the event of a spill or release
  • Conducting site characterizations to determine the extent of soil or groundwater contamination
  • Preparing and implementing corrective action plans
  • Developing reimbursement applications for owners who are eligible for cost reimbursement from the Petroleum Storage Tank Fund

Voluntary cleanup plans

Many states have recognized that historical contamination is limiting development of properties, particularly in urban areas. In response, laws such as Colorado’s Voluntary Cleanup and Redevelopment Act and Idaho’s Land Remediation Act have been passed to encourage voluntary assessment and cleanup of contaminated properties. ERO works with current owners or prospective developers of such properties to determine the extent and magnitude of contamination, and to implement voluntary cleanup plans if necessary. We have worked on former dry cleaner sites, abandoned gasoline stations, firing ranges, and manufacturing and plating facilities.

Environmental Due Diligence Leads