Current through Register Vol. 42, No. 11, August 30, 2024
(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.
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.
