Two lots, two proposed residences
The project involved two proposed single-family residences on adjoining vacant lots in Hesperia. The combined study area was approximately one acre. Each residence required its own evaluation for onsite wastewater disposal.
NGS treated the building investigation and septic testing as related but distinct services. The preliminary geotechnical report addressed both residences, while separate percolation reports identified the conditions and proposed septic system for each lot.
Investigating building support
The geotechnical field program used a truck-mounted drill rig to explore the subsurface and collect samples. NGS logged the encountered materials and performed laboratory testing to evaluate soil properties relevant to grading and foundation support.
The investigation documented sandy alluvial soils and cemented material. The laboratory work included moisture and dry-density measurements, compaction characteristics, shear-strength testing and soil-classification testing. These results supported project-specific recommendations for the proposed residential construction.
Septic testing for each property
The septic investigations considered tank-and-seepage-pit systems for the proposed residences. The reports identified lot size and relatively shallow cemented soils as considerations in selecting that disposal approach.
Exploratory boring information was evaluated alongside percolation measurements from test holes. NGS documented preparation and presoaking of the holes, water-level observations, material descriptions and interpretation of the field results. Each report provided recommendations for its respective lot rather than applying a single undifferentiated result to the two properties.
Keeping the design tasks coordinated
The separate reports allowed the project team to work from a common understanding of the subsurface while keeping foundation recommendations and septic-system requirements clearly identified. The septic studies also considered the area required for the proposed system and its expansion area.
Final grading and foundation plans were not available when the preliminary geotechnical report was prepared. Their review remained a subsequent step. This summary describes the investigation and reporting services, without representing that the proposed homes or septic systems were constructed or approved.
Engineering services by Noorzay Geotechnical Services, Inc. Meet Maihan Noorzay, M.S., P.E., G.E.