ENG SPECIAL INSPECTION REPORT DRIVEWAYC O SA LT Cobalt Geosciences, LLC
GEOSCIENCES P.O. Box82243
Kenmore, Washington 98028
Date: August 2022 Project: Proposed SFR Job No.:
Contractor: Location: 8051184th St SW Weather: Clouds 65
Observations:
At your request and authorization, Cobalt Geosciences, LLC was on site to verify soil conditions
below the proposed permeable driveway. We observed final placement of the uppermost 5/8 inch clean
angular rock over the previously placed larger rock. We understand that the overall section is about 24
inches thick and that gravel grid will be used in lieu of pervious concrete or asphalt.
We previously observed near surface soils consisting of poorly graded sand with silt and gravel (SP-
SM) in the area of the proposed driveway. This was before excavation and replacement with the
angular rock. These materials are consistent with weathered outwash.
The observed soils are suitable to support new paver systems as well as provide drainage for runoff.
We recommend that the surface soils remain clean (no siltation) and that they not be compacted using a
vibratory roller.
The areas must remain free of silt or other materials that may clog the soils. We can provide
additional input upon request.
Sincerely,
Cobalt Geosciences, LLC
44---
Phil Haberman, PE, LG, LEG
Principal
2o63311097; phil(acobaltgeo.com