Ala. Admin. Code r. 420-3-1-.56

Current through Register Vol. 43, No. 1, October 31, 2024

Section 420-3-1-.56 - OSS/EDS Area Requirements

(1) The responsible person shall ensure the following:

(a) The EDF or discharge area shall be constructed so as to encompass the applicable number of permeability tests used to design the OSS or EDS.

(b) An EDF shall not be constructed in Texture Group 3, 4A, 4B, or 4C soils during periods of wet weather or when the soil is sufficiently wet at the depth of installation to exceed its plastic limit. Under these rules, the plastic limit of a soil is deemed to have been exceeded when the soil can be rolled between the palms of the hands to produce threads one-eighth inch in diameter without breaking apart and crumbling.

(c) Special caution shall be taken in allowing vehicles to cross the EDF during wet weather. Protection of Texture Group 3, 4A, 4B, or 4C soils, or fill material, is extremely important. Alteration of soil structure in the EDF area by vehicles may be grounds for the LHD to deny or revoke a Permit to Install (Repair).

(d) Excavating equipment used to construct an OSS shall be operated so as to not compress or smear the sidewalls or bottom of EDF trenches. Excessive smearing of the absorption trench sidewalls or bottom during construction may result in irreversible damage to the soil infiltrative surface and may be grounds for the LHD to revoke a Permit to Install (Repair).

(e) Vegetation with extremely hydrophytic (water-loving) root systems shall be removed for a m.irumum distance of 10 feet from the EDF.

(2) Grading of a site shall comply with the Site Development Plan (SOP), if required.

(3) Grading requirements for sites that do not require an SDP shall be as follows:

(a) Alteration of the natural condition of a site may cause the site rating to be revised to a rating of severe or extreme and may necessitate compliance with the lot modification requirements of 420-3"1-.51 Lot Modification - Planned and Unplanned, or may be grounds for denial or revocation of a Permit to Install (Repair).

(b) Final grading of a site shall divert storm water around the OBS, shall prepare the site for seeding and landscaping, and shall avoid damaging or compacting the EDF area.

(4) When grading for a Controlled Fill Mound System, the engineer's design and the requirements set forth in 420-3-1-.61 Controlled Fill Mound System and 420-3-1-.51 Lot Modification - Planned and Unplanned, shall be followed.

(5) Drainage requirements for an OBS area shall be as follows:

(a) An EDF shall not be located in a depressed area where storm water can accumulate.

(b) The discharge from drains, gutters, roof, condensate, sump pumps, footings, etc., shall be diverted away from the OSS.

(c) An OSS/EDS shall not receive any discharge other than from the building sewer.

(6) Protection of an OSS/EDS by the responsible person shall be accomplished as follows:

(a) No structure shall be placed over a component of the OSS/EDS unless access is provided for repair and relocation of the component.

(b) Lawn sprinkler water supply lines may be installed over an EDF if protected from backflow in accordance with the requirements of the International Plumbing Code. These lines, if installed, should be at least 12 inches above the top of the EDF pipe.

(c) Precautions shall be taken in the design of an EDF proposed for installation under designated playgrounds and athletic fields.

(d) An EDF shall not be located under a driveway or other area subject to vehicular traffic, whether paved or unpaved.

(e) Driveways or parking areas shall not be constructed over other components of the system unless structural provisions are in compliance with the International Plumbing Code. A driveway or parking area shall not obstruct, or limit access points required to operate or maintain a system component. The distribution piping and related devices and materials shall be rated for the anticipated load.

Ala. Admin. Code r. 420-3-1-.56

New Rule: Filed October 20, 2005; effective November 24, 2005; operative March 19, 2006.

Adopted by Alabama Administrative Monthly Volume XXXV, Issue No. 04, January 31, 2017, eff. 3/5/2017.

Adopted by Alabama Administrative Monthly Volume XLI, Issue No. 03, December 30, 2022, eff. 2/13/2023.

Previous Rule .82 was renumbered .56 per certification published December 30, 2022; effective February 13, 2023.

Author: Thad Pittman, Matthew Conner, Ken Stephens, Bob Bright

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