What We Do

Environmental Services

Stratum Group's team of environmental professionals are equipped with the knowledge and experience to conduct and facilitate a full range of environmental services — from initial due diligence through site closure.

Full-Range Environmental Consulting

We regularly work throughout western Washington and also routinely work in central and eastern Washington and periodically in Oregon, Idaho, Montana, and Alaska.

Due Diligence Assessments

  • Desktop records search and risk assessments (RSRAs)
  • Transaction Screen Assessments (ASTM Standard Practice E 1528-22)
  • Phase I Environmental Site Assessments (ESAs) — ASTM E 1527-21 & 40 CFR Part 312
  • Assessments for Bureau of Indian Affairs Fee-to-Trust acquisitions

Environmental Sampling & Characterization

  • Phase II ESAs, remedial investigations, and contaminated site characterization
  • Soil, groundwater, soil vapor, and indoor air sampling
  • Geophysical studies to assess environmental risk (e.g., ground penetrating radar)

Remediation & Cleanup

  • Heating oil tank removal and site assessments
  • Underground storage tank removal and site assessments
  • Development of remedial investigations (RI) and cleanup action plans (CAP)
  • Contaminated site cleanup
  • Vapor intrusion assessments and mitigation

Regulatory & Permitting

  • National and State Environmental Policy Act (NEPA & SEPA) assessments
  • Solid waste permits
  • Permitting support
  • Communication & coordination with WA Dept of Ecology and Pollution Liability Insurance Agency (PLIA)
  • Regulatory compliance and site closure — including No Further Action determinations

All Property Types

Stratum Group has successfully completed thousands of environmental site assessments for financial institutions, tribal and local governments, land trusts, and private property owners.

Undeveloped & Conservation Lands
Single- & Multi-Family Residential
Commercial Properties
Light & Heavy Industrial

We have helped dozens of sites obtain No Further Action determinations from state regulatory agencies. We are ready to start developing a site-specific solution to environmental challenges on your property today.

Past Environmental Projects

A sample of completed projects across the Pacific Northwest, representing the breadth of our environmental consulting experience.

Land Conservation Acquisitions

Stratum Group has conducted hundreds of Phase I ESAs for properties being acquired by the City of Bellingham and several local and national conservation and land trust organizations — helping protect thousands of acres of sensitive habitat, water resource areas, old-growth forest, and critical farmland from future development.

Through the Stratum Group Public Benefit Program, these organizations have saved thousands of dollars, allowing public and private non-profit funding to go further and preserve more land.

City of BellinghamThousands of acres of the Lake Whatcom watershed
Whatcom Land TrustDozens of large & small parcels of mature forest and sensitive riparian habitat across Whatcom County
The Nature Conservancy1,500 acres of critical forest and riparian habitat on the Western Olympic Peninsula
Whidbey Camano Land TrustDozens of large parcels of tidelands, former agricultural land, and forest in Island County
North Olympic Land Trust100s of acres of wild land conserved and productive farmland preserved to support sustainable agriculture

Organizations We Have Worked With

  • City of Bellingham
  • The Nature Conservancy
  • Western Rivers Conservancy
  • Bainbridge Island Land Trust
  • Chelan-Douglas Land Trust
  • Forterra Land Trust Alliance
  • Jefferson County Land Trust
  • Kulshan Community Land Trust
  • North Olympic Land Trust
  • Okanogan Land Trust
  • Skagit Land Trust
  • Whidbey Camano Land Trust
  • Whatcom Land Trust

Tribal Fee-to-Trust


Stratum Group has worked with the Lummi Nation, the Samish Nation, Nooksack Tribe, Swinomish Indian Tribal Community, the Makah Tribe, and the Squaxin Island Tribe to provide environmental consulting for fee-to-trust properties. Recent assessments have been completed for residential, daycare, cemetery, undeveloped, and commercial properties. Our Phase I ESAs have been reviewed and approved by the Bureau of Indian Affairs.

We have also worked with tribes to conduct tank removals, Phase II ESAs, and site remediation in accordance with specific tribal government regulations and requests.

NEPA Assessments


We have worked with several local governments, housing authorities, and non-profit organizations to complete NEPA environmental reviews of new development projects — including coordinating with city and county officials, NOAA, the Washington Department of Archaeology and Historic Preservation, and local tribes.

Work has included review of potential impacts from flood hazards, explosive hazards, toxics and contamination, farmland, noise, aquifers, and waterways. Stratum Group's efforts have helped communities secure grant funding for several projects, including SHOP Grant-funded affordable housing in Ferndale and Blaine, WA.

Ready to start your environmental project?

Contact Kim Ninnemann or Ben Carlson to discuss your site and get a quote.