Environmental Site Assessment and NEPA Consulting

Our environmental professionals have experience and certification to complete due diligence assessments in accordance with ASTM Standards to fulfill the requirements of “all appropriate inquiry” per 40 CFR Part 312.  Our capabilities extend to developed and undeveloped properties of less than one acre to several thousand acres in both urban and rural settings. Our capabilities extend within ASTM and AAI guidelines to completing Phase II ESAs and Phase III remediation planning.  We are likewise proficient in compliance reporting and HAZMAT surveys.


The Timmons Group environmental staff is also accomplished in full NEPA compliance, from initial scoping and studies to design and monitoring of mitigation measures. We work with clients to identify project-specific state and federal NEPA requirements, evaluate potential environmental impacts associated with proposed actions, and recommend appropriate mitigation measures as warranted. Our staff has contributed to every level of NEPA review from local Exempt activities to state-wide Programmatic Environmental Impact Statements. 

As awarded in 2017, Timmons Group is currently the HUD NEPA Review Consultant for Prince William County, Virginia. Any governing body in the United States can place a rider on this term contract to procure HUD NEPA review services from Timmons Group.

ESA Services

  • ASTM E 1527-13 Phase I ESAs for Commercial Properties
  • ASTM E 2247-16 Phase I ESAs for Forestland or Rural Properties
  • ASTM E 1903-11 Phase II ESAs
  • Phase III Remediation Planning and Management
  • ASTM E1528-14e1 Transaction Screen

NEPA Consulting

  • Programmatic Environmental Impact Statements (PEIS)
  • Environmental Impact Statements (EIS)
  • Environmental Impact Reviews (EIR)
  • Environmental Assessments (EA)
  • Categorical Exclusions (CE, CATEX, CENST, CEST)
  • Exemptions
  • Tiered Environmental Reviews
  • HUD Environmental Review Consulting Services