The designing engineer or soil evaluator visits the property to determine where the soil test holes should be dug. Two test holes are marked, one in the uphill position and one in the downhill position. These holes must be located in the area where the leaching field is proposed. Although the septic system design comes after the evaluation, it is helpful to discuss the general location of the house or other structures ahead of time to ensure the septic system is placed appropriately within the landscape.

Property boundaries may have already been marked by a land surveyor, which is often helpful. Nearby site features such as wetlands, streams, ponds, drinking water wells, reservoirs, and any additional regulatory constraints are also reviewed at this stage. Before arriving on site, the evaluator studies topographic maps and the soil survey for the property.

On the day of the evaluation, the soil evaluator and the backhoe operator arrive on site before the state inspector. In Rhode Island, inspections are typically conducted by a representative from the Department of Environmental Management. In some cases, DEM may waive the on site inspection.

The backhoe operator digs two shallow holes, usually to a depth of five feet when possible. The soil evaluator then enters the test holes to conduct the evaluation.

The inspector reviews the soil evaluation form for accuracy upon arrival. Because soil conditions can vary, the evaluator and inspector may discuss the findings together to reach a conclusion about the seasonal high groundwater table and the percolation rate. If both parties agree on the observed conditions, these parameters are finalized at the site. If there is uncertainty, or if the soil type is known to be difficult to interpret, additional testing may be required. In some cases, a wet season determination is necessary to confirm water table conditions.

Once the evaluator and inspector reach agreement, the deep test holes are excavated. The original shallow holes are dug deeper to a depth of approximately ten feet when conditions allow. For safety reasons, neither the soil evaluator nor the inspector enters the deeper holes. Instead, they observe from the ground surface to identify signs of groundwater, soil layers, ledge, hardpan, or other limiting factors.

When the deep hole work is complete, a ten foot length of perforated PVC pipe is placed into the hole and the area is backfilled. This completes the field portion of the soil evaluation.

The soil evaluator transfers all information from the field notes to a clean copy, since field sheets often become stained during the process. The completed soil evaluation is then mailed or hand delivered to the Rhode Island Department of Environmental Management. Once DEM signs the evaluation, copies are sent to both the soil evaluator and the applicant. At that point, the evaluation may also be forwarded to the designing engineer.