How many percolation test holes are required across an absorption field site?

The requirement for at least four percolation test holes across an absorption field site is based on ensuring that there is enough data to accurately evaluate the soil's ability to absorb and treat wastewater. Conducting multiple tests allows for a comprehensive assessment of soil conditions, variations in hydraulic properties, and potential differences in percolation rates across the site. This is crucial since soil characteristics can change, and having more test holes helps ensure that the selected area for the absorption field can effectively handle the effluent being discharged.

By utilizing at least four holes, it provides a more reliable average percolation rate, thus reducing the margin of error in installing the septic system. This thorough assessment helps in designing a system that is efficient and minimizes the risk of failures such as system backups or groundwater contamination. More test holes lead to a better understanding of the site's overall absorption capabilities, which is essential for proper septic system functionality and regulatory compliance.