Geology and Geotechnical Services

Geologic Hazard, Geotechnical and Slope Stability Reports- Puget Sound region and beyond. 

Geology evaluations are completed by licensed engineering geologists and licensed geologists with the State of Washington.

Stratum Group has completed hundreds of geologic hazard assessments for private lots and acreage throughout Washington State. The properties have included steep slopes, coastal bluffs, rock fall hazards, debris flow and alluvial fan hazards, bedrock faults, shallow and deep-seated landslide areas, and erosion hazards.

Reports include review of geologic mapping and lidar imagery of the area, a thorough site inspection of site and vicinity for indications of instability, test pit excavation, and recommendations for storm water and setbacks from the geologically hazardous areas.

Verbal and written reports are prepared for property owners, developers, potential buyers, and for compliance with municipal regulations.

Geologic Hazard Mapping, Critical Areas Code Writing, and Best Available Science Reviews.

We have provided our geologic expertise for critical areas code writing, amendments, and commentary. We have also performed multiple best available science reviews and completed geologic hazard mapping for municipalities. 

Mineral Remoteness Assessment Reports– Puget Sound region and beyond 

Stratum Group has diverse and extensive experience with the geology of Washington State. Therefore, we are well-suited for performing mineral remoteness assessments to evaluate the likelihood of mineral, hydrocarbon, and/or aggregate extraction on properties where mineral rights were retained by previous landowners. These types of assessments are often done for land trusts or private property owners.

Gravel Pit Evaluations

Stratum Group performs evaluations of current and potential gravel mines to determine resource quantity, quality, and marketability.

Project Portfolio

Fort Lawton Army Reserve Center Redevelopment, Seattle, WA

Client:  City of Seattle

Assessed the geology and geotechnical constraints as well potential environmental issues for the redevelopment of the Fort Lawton Army Reserve Center. The proposed redevelopment entailed an affordable housing project. The project involved a public meeting with City planners and recommendations for geotechnical limitations and geology hazards were evaluated for feasibility purposes under the initial proposed redevelopment. Setbacks from a steep slope and vegetation management recommendations were included in the report. The report also evaluated the potential impacts of low impact development on the site in regards to storm water infiltration to on site slopes and off site slopes and existing development. 

Balfour, Village, Kendall, WA

Client:  Aiki Homes

Evaluated geologic hazards associated with steep slopes and eight streams at a proposed 750 unit subdivision in Kendall, Washington.  Flooding, debris floods, debris flows and erosion hazards were identified on all of the streams. Hazards were delineated and mitigated through a combination of avoidance and recommended engineered designed berms and stream flood routes designed for the maximum credible peak discharge events. Provided geotechnical support for design and location of storm water infiltration areas for a low impact development.

Gravel Pit Evaluation, Sumas

Client:  property owner

Oversaw five geotechnical borings to a depth of approximately 45 feet.  Soil samples were collected every five feet to evaluate the subsurface deposits.  Soil samples were sieved and analyzed for material quality.  Assessments were completed to estimate the volume of material for mining, likely price of material per ton based on a long term market evaluation that included an evaluation of existing and potential resources within the market area as well as potential demand for the product.

Swinomish Northern Lights Casino RV Park, Anacortes, WA

Client:  Swinomish Tribe

Authored the Environmental Assessment (EA) under the National Environmental Policy Act for a proposed RV Park adjacent to the Swinomish Channel east of Anacortes, Washington. The EA included evaluation of impacts to traffic, shorelines, a base line air quality monitoring station and wildlife impacts and mitigation measures.

Boundary Dam, Pend Orielle River, Washington

Client:  Seattle City Light

Developed an erosion study plan for a 20 mile long reservoir in northeast Washington State. The study was developed to evaluate erosion impacts to fish, wildlife, archeological sites and mine waste rock sites. The study was developed in coordination with other technical studies on the lake. The study was approved by several public agencies including Seattle City Light, the United States Forest Service, and the Federal Energy Regulatory Commission. The study was successfully completed in 2008.

Shoreline Stability Reports

Client:  property owners

Stratum Group has completed hundreds of slope stability assessments for private lots and acreage within the Puget Sound region. The properties have included steep slopes, rock fall hazards, bedrock faults, shallow and deep seated landslide areas, and erosion hazards.  Reports include review of geologic mapping of the area, a thorough site inspection of site and vicinity for indications of instability, test pit excavation, and recommendations for storm water and setbacks from the geologically hazardous areas.