Gary Sandstrom home
Gary C. Sandstrom,
Geologist, LLC

Certified Engineering Geologist

Real Estate Services

Geohazard Evaluation

Slope Stability and Landslide Risk – Examine site vicinity and geologic literature for indications of past, present or potential slope failure.

Drainage and Flooding Risk – Determine where storm run-off flows, evaluate flooding potential of streams, ponds, etc., determine need for and feasibility of interceptor and/or drainage trenches.

Erosion and Bluff Recession – Advise on likely erosion hazards and how to reduce erosion rates if possible, recommend set-backs.

Foundation Settlement Assessment

Existing Structures – Examine existing structures for indications of differential sub-grade settlement, adequacy of roof run-off and other drainage systems.

Planned Structures – Identify soil type, slope and drainage characteristics that impact design of foundations, likely need for retaining walls, foundation drains, etc.

Geohazard Reports

Gary has inspected and drafted stamped reports for hundreds of sites intended for owners of distressed properties, prospective home buyers, developers, and land-use planners. Reports requiring an engineering geologist stamp need documentation of findings and cost more than unstamped reports.

Several government agencies in Oregon (including Lincoln County and the Cities of Portland and Salem) require engineering geologists to make recommendations (e.g., set-back distances or need for deep foundations) when prospective building sites are mapped in areas of known geologic hazards (such as bluff recession or steep, unstable slopes).

Reports to these agencies may require documentation stamped by an engineering geologist alone, or by both an engineering geologist and geotechnical engineer. Reports may be as simple as documenting the project site does not meet the hazard criteria (such as building on a relatively flat bench in an otherwise steeply-sloping vicinity) or as complex as teaming with a geotechnical engineer to recommend site modifications such as deep foundations (piles, walk-in basements), retaining walls or drainage systems.

Foundation, gutter and drain inspections of existing buildings for real estate clients may not require a certification stamp.


634 SW 54th St
Corvallis OR 97333

Cell 503-547-3678