Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 604 - DESIGN, OPERATION, AND MAINTENANCE CRITERIA
Subpart K - CHEMICAL APPLICATION
Section 604.1150 - Fluoride
Universal Citation: 35 IL Admin Code ยง 604.1150
Current through Register Vol. 48, No. 12, March 22, 2024
a) Basis of Design. Equipment must have the capacity to maintain the fluoride content in the finished water at 0.7 mg/L.
b) Chemical Feed Equipment
1) A free chlorine
residual of 10 mg/L must be maintained in solutions prepared from dry
chemicals. This chlorine residual must not replace the chlorination requirement
of Section 604.725.
2) Chlorine
must not be added to hydrofluosilicic or fluorosilicic acid
solutions.
3) Diaphragm operated
anti-siphon devices must be provided on all fluoride saturator or fluorosilicic
acid feed systems as follows:
A) one
diaphragm operated anti-siphon device must be located on the discharge side of
the feed pump; and
B) a second
diaphragm operated anti-siphon device must be located at the point of
application unless a suitable air gap is provided.
c) Chemical Feed Methods
1) Fluoride compound must not be added prior
to filters at plants that lime soften or coagulate for turbidity removal, and
must not be added prior to ion exchange softeners.
2) The point of application, if into a
horizontal pipe, must be in the lower half of the pipe, preferably at a
45-degree angle from the bottom of the pipe, and protrude into the pipe one
third of the pipe diameter.
3)
Water used for sodium fluoride dissolution must be softened if hardness exceeds
75 mg/L as calcium carbonate.
4)
Saturators must be provided with a meter and backflow protection on the make-up
water line.
d) Secondary Controls. Secondary control systems for fluoride chemical feed devices must be provided as a means of reducing the possibility for overfeed. These may include flow or pressure switches, break boxes, or other devices.
e) Samples must be submitted monthly to a certified laboratory to determine compliance with 35 Ill. Adm. Code 611.125.
Disclaimer: These regulations may not be the most recent version. Illinois may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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