DDW-2024-009118

July 22, 2024
Judy Hamblin
CedarviewMontwell SSD
270 North 500 West
Roosevelt, Utah 84066
Subject:TemporaryException to R309-510-7, Source Sizing for CedarviewMontwell SSD
System #07072, File #15815
This Temporary Exception Expires on December 31, 2027
On July 17, 2024, the Division of Drinking Water (the Division) received a request from Sunrise Engineering on your behalf for an exception to Rule R309-510-7 regarding minimum source
sizing. According to this rule, Community water systems that do not have system specific sizing established by the Division are required to provide source flows to meet 800 gallons per
day (gpd) per connection and 800 gpd per equivalent residential connection (ERC), plus outdoor watering demand based on estimates of irrigated acres and the relevant soil/climate zone.
The basis for your request for an exception to R309-510-7 is that, based on usage records, your water systems’ peak day demand is less than required by the rule as follows:
According to source meter data from your consecutive connection source, the peak month of usage during the last three years was 1,535,000 gallons.
Your consecutive connection supplier does not read daily flows, only monthly. You propose to use a 1.24 peaking factor established over the last four years by Tridell Lapoint WID, which
is a neighboring water system with similar demographics and usage. With this peaking factor, your peak day demand is 538 gpd/ERC. You propose to incorporate a 20% safety factor, which
results in a proposed total peak day demand of 646 gpd/ERC.
On this basis, an exception to R309-510-7, Source Sizing, is hereby granted, resulting in a minimum source capacity requirement of 646 gpd/ERC for your water system, with the following
conditions:
This Temporary Exception expires on December 31, 2027
The Division recommends that you install metering that will allow you to measure and record your daily demand so you can determine your own Peak Day demand.
You will be required to re-submit an exception request along with updated usage data and calculations and obtain an exception renewal prior to December 31, 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 by the due date will result in the Division reverting back to minimum source requirements outlined
in the rule.
This Temporary Exception may be rescinded if the required peak day source requirement is replaced by System Specific Sizing established by the Division, or any time that new evidence
indicates that the usage, calculations, or conditions of this exception are no longer being met or a public health risk exists due to this exception.
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 Nathan Hall, P.E., TriCounty DEQ District Engineer at [phone], or Michael Newberry, P.E., Permitting
and Engineering Manager, at [phone].
Sincerely,
Russell Seeley, P.E.
Assistant Director
NDH/mrn/mdb
cc: Joe Hadlock, TriCounty Health Department, [e-mail]
Judy Hamblin, CedarviewMontwell SSD, [e-mail]
Jeff McCarty, Sunrise Engineering, [e-mail]
Nathan Hall, P.E., DEQ District Engineer, [e-mail]
Nagendra Dev, P.E., Division of Drinking Water, [e-mail]
Nhall 07072 15815 Exception to source requirement