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-.42 - Soil Restriction Depth And Vertical Separation

Universal Citation: AL Admin Code R 420-3-1-.42

Current through Register Vol. 43, No. 02, November 27, 2024

(1) The MVS between the deepest EDF bottoms and any noted restriction as defined by these rules shall be required. See Table 7 for specific depth requirements.

(2) The depth to the ASHES is approximated by the shallowest occurrence of contemporary redoximorphic features containing 2 percent or more chroma 2 or less (Munsell or equivalent) colors (See Table 7 footnote 4). MVS is based on chroma 2 or less colors; however, saturation often occurs above these gray colors for shorter durations indicated by the accumulation of contemporary oxides. The EDF bottoms shall be at least the same elevation or shallower than the top of this zone. If there is sufficient evidence to suspect saturation occurs even higher than any obvious redox features for a significant period, groundwater monitoring may be required for a minimum of one normal wet season.

(3) When the soil professional performing the evaluation encounters difficulty in determining the depth of the ASHES, he or she should consult with the LHD.

(4) When actual monitoring is required to make a determination of the ASHES, a proposed plan shall be submitted to the LHD and ADPH for review and approval.

(5) The LHD or ADPH reserves the right to make the final determination concerning ASHES and useable soil depth.

(6) Other soil features that may occur in or below the soil and restrict the downward movement of water or hinder treatment of effluent shall be considered a restrictive layer or horizon. These features may include, but are not limited to, the following:

(a) Bedrock layers that are tilted and variable in depth from the surface shall be treated as restrictive when the consistent mass of hard or soft bedrock exceeds 50 percent by volume.

(b) Some parent material layers with poor or massive structure and without adequate conducting pores (slowly or very slowly permeable).

(c) Fragipans or similar features with inherent dense or brittle qualities.

(d) A layer or layers of fill or mine spoil that has less than 50 percent soil size particles, or greater than 50 percent coarse fragments with 2 percent or more empty voids between fragments, or greater than 75 percent coarse fragments larger than gravel size.

(e) One or more layers of fill or mine spoil that have been compacted.

Previous Rule .66 was renumbered .42 per certification published December 30, 2022; effective February 13, 2023.

Author: David Gray, John Clement, Boyd Rogers, Richard Smith

Statutory Authority: Code of Ala. 1975, §§ 22-2-2(4); 22-2-2(6); 22-10-1, et seq.; 22-26-1et seq.

Disclaimer: These regulations may not be the most recent version. Alabama may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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