REVIEWED RESUB1 REV 1 BLD2019-1553 Paver GEO SUBGRADE MEMO JUNE 2022RESUB REVISION
Jul 19 2022
Jul 19 2022
CITY OF EDMONDS
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEVELOPMENT SERVICES
DEPARTMENT
DEPARTMENT
BLD2019-1553
C D B A LT Cobalt Geosciences, LLC
P.O. Box 82243
GEOSCIENCES
Kenmore, Washington 98028
Date: June 2022 Project: Proposed SFR Job No.:
Contractor: Location: 8051184th St SW Weather: Clouds 55
Observations:
At your request and authorization, Cobalt Geosciences, LLC was on site to verify soil conditions
below the proposed permeable driveway. We observed coarse angular rock topped with smaller
clean angular rock over the driveway area. We understand that the overall section is about 24
inches thick.
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
Phil Haberman, PE, LG, LEG
Principal
2o63311097; phil(a)cobaltgeo.com