can I build single families on Los Osos and bedrock on slope? 1

[beautifulhills]

I am considering buying land in El Sobrante CA, ranging from steep slope to gentle slope on the same land. This is 12 miles west of Martinez CA and 4 miles north east of Richmond.
For single family home development.

The soils are Los OSOS dull brown surface soils 7 – 10 in thick (and related/similar soils) Upper subsoil 16 – 24 inches slightly compact partly weathered rock fragments 36 to 45 inc same With depth these layers contain increasing quantities of sandstone or shale rock fragments. Root cavities stained with ye3llowish brown colloidal deposition. Non calcareous Parent bedrock contains some lime

Cam I build appropriate foundations for single family on this type of soil?

There is lots of 1940s 1950s development, but for reasons probably unrelated to soils I don't see a lot of new construction - mainly due to lack of lots to build.

 

[Okiryu]

I think you will need a geotechnical engineer on board to provide site specific investigation/recommendations.

 

[beautifulhills]

Okiryu:- Yes indeed. My question was really quite a general one. Before stroking the check, I m hoping that if it is a definite no, then I can discover this now. I don't believe it is a no.

 

[Okiryu]

Soil conditions met be okay for shallow foundations. But check for slope stability if you are constructed close to the slopes...

 

[cvg]

suggest a geologic appraisal which is really hard to do on a forum.

[ul]
[li]looks like you might be immediately downstream of san pablo and briones dams. recommend you do not buy if you are in the inundation area for these reservoirs.[/li]
[li]you also have the pinole, moraga and wild cat faults and a stones throw from the Hayward fault. Hayward is high risk[/li]
[li]according to the NRCS soil survey, the soil is almost all clay and not ideal for construction of shallow foundations or roads.[/li]
[/ul]

It appears that geohazards might be high risk and make this expensive to develop.

 

[beautifulhills]

cvg thank you for info on the dams. hayward fault line is close. very few soils are ideal in this are. Thanks okiryu

 

[fel3]

Beautifulhill…

I lived in El Sobrante from 1961 to 1963, on Robinhood Drive, but I was not quite 5 when we moved, so I can't offer any useful information. To me, the brown stuff in the back yard was dirt, not soil.

Fred

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[beautifulhills]

thank you