Using Web-Based Site & Soil Tools for Conducting Evaluations for On-Site Sewage Treatment Systems.

Site and soil evaluations for on-site sewage treatment systems are a combination of field and office tasks. Field tasks center around physically visiting the site (lot), evaluating the vegetation, slope, natural drainage, and where certain "hardscapes" will be located. A soil profile description is conducted by either using a hand auger or a pit. This profile description is necessary to determine depth to: a perched seasonal water table, bedrock, restrictive layer, and soil loading rates. Office tasks center around obtaining various maps of the lot, writing a report of field findings, and determining if a system is feasible. On-line tools are a big help in doing these tasks. For example, the USDA Web Soil Survey helps to see what soils were mapped in the area of the lot. Some counties in Ohio through the auditor's office or through their GIS office can provide online drawings of the lot with roads and dimensions. An online contour map with 2-foot contour lines is a helpful asset in planning where to dig test borings or pits and where to locate the soil treatment system. These soil treatment systems generally are placed parallel to the contour lines as opposed to crossing contour lines. In this way they are placed across the slope and not up and down the slope. These online tools are a valuable aid for a consulting soil scientist.