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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Ave, Suite 613, Portland, OR 97204

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Soil Sampling and Geotechnical Investigations

To plan for sewer and stormwater improvements, it is important to know the conditions that engineers and construction crews will encounter underground—the soil types, soil conditions, water levels, rocks, pavement layers, and whether any contaminated soils are present. This information will help engineers determine the appropriate methods to use in constructing the sewer and stormwater improvements.

Before crews can obtain the samples, they must first locate and mark underground utilities to identify safe drilling locations. To obtain the soil, rock, water, and pavement samples, crews dig small holes in street pavement and collect the samples. When soil sampling is complete, crews fill the holes.