Current through Vol. 41, No. 13, March 15, 2024
(a)
Natural draft aeration.
Provide the following:
(1) perforations in
the distribution pan 3/16 to 1/2 inches in diameter, spaced 1 to 3 inches on
centers to maintain a 6 inch water depth,
(2) distribution of water uniformly over the
top tray,
(3) discharge through a
series of 3 or more trays with separation of trays not less than 12
inches,
(4) loading at a rate of 1
to 5 gal/min/ft2 of total tray area,
(5) trays with slotted, heavy wire (1/2 inch
openings) mesh or perforated bottoms,
(6) construction of durable material
resistant to aggressiveness of the water and dissolved gases,
(7) an enclosure with louvers sloped to the
inside at an angle of approximately 45 degrees, and
(8) 24 mesh screen for protection from
insects.
(b)
Forced or induced draft aeration. Design devices to:
(1) include a blower with a weatherproof
motor in a screened enclosure,
(2)
ensure adequate counter current of air through the enclosed aerator
column,
(3) exhaust air directly to
the outside atmosphere,
(4) include
a down-turned and 24-mesh screened air outlet and inlet,
(5) ensure air introduced in the column is as
free from obnoxious fumes, dust and dirt as possible,
(6) ensure that sections of the aerator can
be easily reached or removed for maintenance of the interior or installed in a
separate aerator room,
(7) provide
loading at a rate of 1 to 5 gal/min for each square foot of total tray
area,
(8) insure that the water
outlet is adequately sealed to prevent unwarranted loss of air,
(9) discharge through a series of 5 or more
trays with separation of trays not less than 6 inches,
(10) provide distribution of water uniformly
over the top tray, and
(11) be of
durable material resistant to the aggressiveness of the water and dissolved
gases.
(c)
Other
methods of aeration. Other methods of aeration may be used including but
not restricted to spraying, diffused air, cascades, packed tower, and
mechanical aeration. Treatment processes designs are subject to the approval of
the DEQ.
(d)
Protection of
aerators. Locate air inlets for mechanical aerators in an area free from
obnoxious fumes, dust, dirt, or other contaminants.
(e)
Disinfection. Provide
chlorination, as the minimum additional treatment, for ground water supplies
exposed to the atmosphere by aeration.
Added at 18 Ok Reg 1612,
eff 6-1-01
