Hire a Registered Engineer. Attach the report from the Soil Scientist. Special caution shall be taken to prevent wheeled and tracked vehicles from compacting the area selected for placement of the absorption system before, during, and after construction of the trenches, especially during wet weather.
Precaution is especially important where clayey soils are involved.
This includes those soils classified as sandy loam, silt loam, loam, clay loam, silty clay loam, sandy clay, silty clay, and clay. Subsurface soil absorption systems shall not be constructed in clayey soils during periods of wet weather when the soil is sufficiently wet at the depth of installation to exceed its plastic limit. This includes those soils classified as sandy loam, silt loam, loam, clay loam, silty clay loam, sandy clay, silty clay, and clay.