DDW-2024-007533

May 9, 2024
Mike Rau
CUWCD - Ashley Valley
1426 East 750 North Suite 400
Orem, Utah 84097
Subject:TemporaryException to R309-525-16(1)(b) and (b)(i), In Plant Contact Time, Ashley Valley Water Treatment Plant (TP003); Central Utah WCD - Ashley Valley, System #24038, File
#14197
This Temporary Exception Expires on April 29, 2027.
Dear Mike Rau
On April 22, 2024, the Division of Drinking Water (the Division) received your request for an exception to Rule R309-525-16(1)(b) and (b)(i) regarding an inadequately designed clear
well to provide the required disinfection contact time (CT). According to these rules, the clear well storage shall be sized, in conjunction with distribution system storage, to relieve
the filters from having to follow fluctuations in water use. Also, when finished water storage is used to provide the CT for chlorine, special attention must be given to size and baffling.

Exception Request
The basis for your request for an exception to R309-525-16(1)(b) and (b)(i) is that CT cannot be adequately demonstrated for the in-plant finished drinking water supply. You propose
to provide bottled water to workers and visitors and place appropriate signage stating “non-potable water” near all taps within the treatment plant. This will be done until a new design
and construction is completed to properly demonstrate adequate CT to provide equivalent protection for public health to meet the intent of the rule.
On this basis, an exception to R309-525-16 (1)(b) and (b)(i),In-Plant Finished Drinking Water Storage, is hereby granted for the Ashley Valley Water Treatment Plant (TP003).
This Temporary Exception expires on April 29, 2027.
Submit documentation that shows that adequate CT is demonstrated for the in-plant drinking water supply.
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 April 29, 2027.
Exceptions granted by the Division include an expiration date to ensure that the basis and conditions for granting the exception are verified periodically and that the drinking water
quality remains protected. After receiving your request, the Division will determine whether this exception can be re-issued.
Failure to request the re-evaluation of this exception and obtain an exception renewal or CT documentation by April 29, 2027, will result in the activation of the deficiency related
to not demonstrating adequate CT for in-plant drinking water supply.
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 T096. An updated IPS report isavailable 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, Permitting and Engineering Manager,
at [phone].
Sincerely,
Russell Seeley, P.E.
Assistant Director
CM/mrn/mdbcc:Darrin Brown, Tri-County Health Department, [e-mail] Rau, CUWCD - Ashley Valley, [e-mail]
Chris Martin, P.E., Division of Drinking Water, [e-mail] Yee, Division of Drinking Water, [e-mail]
Nagendra Dev, P.E., Division of Drinking Water, [e-mail]
Nathan Hall, P.E., DEQ Tri-County Health District, [e-mail]
CMartin 24038 14197 Exception