SECTION 252:626-9-3. Aeration

(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/ftof total tray area,

(5)   trays with slotted, heavy wire (½ 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.

[Source: Added at 18 Ok Reg 1612, eff 6-1-01]