Alabama Administrative Code
Title 420 - ALABAMA STATE BOARD OF HEALTH
Chapter 420-3-1 - ONSITE SEWAGE TREATMENT AND DISPOSAL
Site Evaluation
Section 420-3-1-.43 - General Percolation Procedure

(1) A site may be evaluated using the percolation method by first boring a hole or digging an observation pit to establish the depth of the ASHES or other restrictive layer or horizon. The test hole depth is determined by 420-3-1-.40 Soil Testing Depth Requirements. For the minimum number of tests required see Table 19.

(2) A valid percolation test shall be performed in accordance with this rule and 420-3-1-.40 Soil Testing Depth Requirements, 420-3-1-.44 Soil Boring Procedure (for Percolation Testing), and 420-3-1-.45 Percolation Test Procedure.

(3) For Small-Flow single-family dwellings, a minimum of two percolation tests shall be required for each EDF, and one percolation test shall be performed in the REDF for lots of less than 15,000 sq. ft. See Table 17 for exceptions. The test holes shall be located no closer than 30 feet apart. The test holes shall be evenly spaced to represent the EDF area.

(4) For Large-Flow systems and establishments, a minimum of two percolation tests and two borings shall be required for the initial 600 gpd. One percolation and one boring shall be required for each additional 600 gpd of flow or portion thereof thereafter. The test holes shall be evenly spaced to represent the EDF area.

(5) Percolation tests shall not be conducted in stump holes, large root channels, fractured bedrock, or in association with any other factors that might cause test results to be non-representative of the actual site conditions. No soil additives shall be used in the percolation testing process.