Ala. Admin. Code r. 420-3-1-.62

Current through Register Vol. 42, No. 8, May 31, 2024

Section 420-3-1-.62 - Drip Irrigation Requirements

(1)General. The drip irrigation field size shall be based on Table 12.

(a) All components shall be designed and manufactured to conform to the applicable ASTM standards for sewage disposal.

(2)Installation. Drip lines shall have a minimum soil cover of 6 inches and a maximum depth of 12 inches from final grade.

(a) The standard spacing for drip lines and drip emitters shall be 24 inches. The drip lines shall be laid level and shall run with the contour. The maximum length of a drip line and drip zone size, measured from the supply line to the return manifold, shall be specified and comply with the drip tube manufacturer's requirements.

1. For slopes exceeding 20 percent, the minimum spacing shall be 36 inches. However, the spacing due to slope shall not reduce the total linear footage of drip tubing required.

2. Any other spacing of the drip lines and emitters shall require ADPH approval.

(b) Vacuum breakers shall be placed at the highest elevation of a drip field or zone under protective cover and with grade level access. The maximum elevation difference, from lowest to highest point of a drip field or zone shall be 8 feet when using non-pressure- compensating drip emitters.

(c) All drip irrigation systems shall be equipped with pressure regulators or compensating devices to achieve uniform distribution over the entire drip field or zone.

1. The operating pressure necessary to fully pressurize a drip field or zone shall be within the pressure ranges specified by the drip tube manufacturer and shall be described in the drip irrigation manual. Pump selection shall take account of the operating pressure appropriate for the drip irrigation field, which shall be fully pressurized throughout the dose cycle, and the total dynamic head required for dosing and flushing.

(d) The drip line shall be installed in such a manner as to prevent pulling, stretching, or crimping of the drip line; or smearing, compaction, or damage to soil. A trencher with moving blades shall not be used to install drip tubing in Group 3 or 4 soils.

(3)Operation. Each drip irrigation field or zone shall be time-dosed at least six times per day (24 hours) at regular intervals. A programmable timer and control panel shall be employed to regulate the dosing frequency and volume.

(a) All drip irrigation systems shall employ a method of filtration adequate to remove suspended solids from the sewage. The filtration method used shall meet the standard specified by the drip tube manufacturer.

(4)Package Permitting. For the approval of drip packages with a design flow of 1,800 gpd or less, the applicant (a manufacturer of the drip tube or a secondary treatment device) shall submit to ADPH for review and approval a request for a Product Permit. The application shall list the advanced treatment device and all equipment (including manufacturer and model number) to be used with the drip package. In addition, the application shall include a letter or other certification from each component manufacturer stating that the component is appropriate for the intended use.

(a) The system will be permitted as a package and shall be installed as a package. The manufacturer of an advanced treatment device who intends to place a package drip field behind its treatment device shall design its own drip package or have an agreement with an existing drip field (system) manufacturer to use an approved package. This agreement shall be referenced in the Product Permit. Conversely, the manufacturer of the drip tubing may also hold a Product Permit by agreement with an ATS manufacturer.

(b) The drip package applicant shall demonstrate under what conditions (single or multiple zone) the package will be hydraulically stable and the conditions under which it may be used without modification.

(5)Non-packaged Permitting. A drip irrigation system may be permitted that is not part of an approved package as long as the OSS complies with these rules, requirements of the drip tube manufacturer, and requirements of the ATS manufacturer.

Ala. Admin. Code r. 420-3-1-.62

New Rule: Filed October 20, 2005; effective November 24, 2005; operative March 19, 2006. Amended: Filed October 19, 2006; effective November 23, 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 .90 was renumbered .62 per certification published December 30, 2022; effective February 13, 2023.

Author: Thad Pittman, Leigh Salter, 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.; 22-25B-1, et seq.