DDW-2024-006091

February 21, 2024
Jay L. Brems
American Fork City
51 East Main Street
American Fork, Utah 84003
Subject:Temporary Exception to R309-545-10(1), Tank Drain for the Lower Tank (ST003); American Fork City, System #25008, File #12389
This Temporary Exception Expires on March 12, 2027
Dear Jay Brems:
On February 8, 2024, the Division of Drinking Water (the Division) received your request for an exception to Rule R309-545-10(1) regarding the tank drain, for the Lower Tank (ST003).
According to this rule, if a tank drain line is provided, it shall be sloped for complete drainage and if the local authority allows discharge to a storm drain, the drain discharge shall
have a physical clearance of at least 12 inches between the discharge end of the pipe and the overflow rim of the receiving basin.
Background
It is our understanding that when the 4,500,000-gallon Lower Tank (identified as ST003 in the Division’s database) was constructed in 2001, the tank drain line was connected below grade,
discharging to the storm drain system. The following summary provides relevant details related to this tank drain line discharge exception request:
This temporary exception request only relates to the tank drain line, which discharges separately from the tank overflow.
The foundation drain line connects to the tank drain line in a maintenance access. The foundation drain line was disconnected from the tank drain line and the flow is directed to a new
sump.
The tank overflow for this tank discharges onto the ground next to the tank and could flow overland to a maintenance hole on the tank drain line. Any overflows will be redirected to
an adjacent storm water detention facility away from the tank drain line. Two of the three (3) maintenance holes, located at Station 11+42 and 12+38, on the tank drain line will be fitted
with a sealed and lockable solid lid.
The tank drain also has a siphon located between the maintenance access from approximately station 11+42 to 12+38. The approximate invert elevation of each pipe into and out of these
maintenance accesses is approximately 4,821 feet. The rim elevation of the storm drain maintenance hole is at an elevation of 4,811.23 feet. Therefore, flow will be through the maintenance
hole before overcoming the siphon and entering the tank if the downstream drain is plugged. The standard operating procedure (SOP) presented in the enclosure shows the siphon.
The drain line discharges into a storm drain maintenance hole, about 3 feet above the flow line for the storm drain system.
The storm drain maintenance hole rim elevation is at an elevation of 4,811.23 feet and the bottom of the tank is at an elevation of approximately 4,825 feet. The elevation of the bottom
of the tank is approximately 13.77 feet higher than the storm drain rim elevation. The SOP presented in the enclosures shows the elevation relationship between the tank and storm drain
maintenance hole.
Basis for Exception Request
Your request for an exception to R309-545-10(1) is based on the following information:
The drain line has a permanent valve that is normally in the closed position. The drain line valve is only opened when the tank is drained and discharges to the storm drain. This drain
line, unlike the overflow discharge, is not an open pipe into the storage tank.
The drain line valve is only opened when the tank is drained every 5 to 10 years for inspection and cleaning purposes. American Fork City has a tank drain Standard Operating Procedure
(SOP) in place to visually monitor the drain for any backflow events. Upon completion, the tank drain SOP requires the tank to be cleaned and disinfected per AWWA standards before being
put back into service.
Based on the hydraulic grade and elevation difference between the overflow rim of the storm drain grate and the elevation of the bottom of the tank, a backflow event is unlikely. The
elevation of the bottom of the tank is approximately 13.77 feet higher than the storm drain maintenance hole grate elevation. Therefore, during a potential storm surge event or obstructed
storm drain line downstream of the storm drain maintenance hole, water would overflow the storm drain maintenance hole grate before water would reach the elevation of the tank drain.
Temporary Exception Request to R309-545-10(1) and Conditions
On this basis, a Temporary Exception to R309-545-10(1), Internal Features, Drains, is hereby granted for the 4,500,000-gallon Lower Tank (ST003) subject to the following conditions:
This Temporary Exception expires on March 12, 2027:
You will be required to re-submit an exception request along with confirmation that all conditions outlined in this temporary exception have been fulfilled and obtain an exception renewal
prior to March 12, 2027.
The issuance of this Temporary Exception temporarily silences the deficiency related to the drain line discharge for the 4,500,000-gallon Lower Tank (Deficiency code V016, End of drain
line lacks a clearance of at least 12 inches) until March 12, 2027.
Failure to request the reinstatement of this exception by March 12, 2027, will result in reactivation of the dormant deficiency (V016, End of Drain Line Lacks a Clearance of at Least
12 inches) assessed to your system.
Ongoing Site Assessment
Conduct monthly inspections of the storm drain maintenance hole to visually inspect and document any potential backflow risks and take actions accordingly if needed.
Document ongoing site assessments through record keeping. Maintain the records as part of your water system’s Cross Connection Control Program.
Continue to comply with your SOP in monitoring potential backflow when the tank drain valve is opened for tank draining.
Continue to comply with all monitoring and reporting requirements.
This Temporary Exception only applies to the existing 4,500,000-gallon Lower Tank (ST003) and will not apply if this tank is replaced in the future.
This Temporary Exception may be rescinded at any time if new evidence indicates that the conditions of this exception are no longer being met or a public health risk exists due to this
exception.
The issuance of this exception temporarily resolves your water system’s deficiency related to V016. An updated IPS report is available at https://waterlink.utah.gov. Please contact Jennifer
Yee at [phone] or [e-mail] for questions related to your water system’s IPS report or deficiencies.
Please maintain a copy of this letter with your permanent records for future reference.
If you have any questions regarding this temporary exception, please contact Chris Martin, of this office, at [phone], or Michael Newberry, Engineering Manager, at [phone].
Sincerely,
Russell Seeley, P.E.

Assistant Director
CM/mrn/mdbEnclosure:Lower Tank Drain - SOPcc:Jason Garrett, Utah County Health Department, [e-mail] Jay L. Brems, American Fork City, [e-mail] L. Brems, American
Fork City, [e-mail] Martin, Division of Drinking Water, [e-mail] Jennifer Yee, Division of Drinking Water, [e-mail]
CMartin 25008 12389 ST003 - Exception to R309-545-10(1)