What information is typically gathered during an OSSF site evaluation?

During an OSSF site evaluation, soil type, depth to groundwater, and lot size are critical factors that are assessed to ensure the suitability of a site for an on-site sewage facility.

Soil type is important because different soils have varying absorption capacities, which directly affect how well water will infiltrate the ground and how efficiently the OSSF will function. For example, sandy soils drain quickly whereas clay soils retain water, which can lead to failures if not properly considered.

The depth to groundwater must be evaluated as well to prevent contamination of the water supply from sewage effluent. Regulations often require that a certain distance be maintained between the bottom of the sewage system and the groundwater table to ensure proper drainage and to reduce risks of pollution.

Lot size is also a significant factor since it determines whether there is enough space to install an appropriate sewage system and to meet required setbacks from property lines, wells, and other features. A minimum lot size may be mandated to ensure that the system functions correctly without impacting neighbors or the environment.

Overall, gathering this specific information during a site evaluation helps ensure that the OSSF will operate effectively and safely.