DWQ-2024-007334

PUBLIC COMMENTS RESPONSE SUMMARY
HYRUM CITY
UPDES PERMIT NO. UT0023205
October 10, 2024
Outline
Public Notice and Hearing Information
Written Comments
Response to Comments
Public Notice and Hearing Information
Summary: The Utah Division of Water Quality (“DWQ”) provided Public Notice regarding the draft Utah Pollutant Discharge Elimination System (“UPDES”) Permit for Hyrum City Wastewater
Treatment Plant (“Plant”), operated by Hyrum City (“Hyrum”), on the DWQ webpage on August 23, 2024. The public comment period was open until September 23, 2024. No public hearing was
requested and no public hearing was held.
Written Comments
Hyrum City submitted comments on the permit renewal in the form of a letter dated September 18, 2024.
Documents (available by request):
1. Written Comments (DWQ-2023-200118)
Response to Comments
A total of six comments were received during the public notice periods. This document has been developed to address all comments received. Comment 1 The proposed limit for dissolved
oxygen (DO) is 6.5 mg/L. The reasoning in the statement of basis for the inclusion of a do limit is due to the listing of Spring Creek on the 303(d) list for D.O. The tmdl completed
in 2002 severely limited or phosphorus discharge to address do and other pollutants of concern in Spring creek. there was no recommendation in the TMDL to include a DL limit within
the city's permit. the actual discharge from the plant is over a mile Upstream from Spring Creek into an irrigation ditch that is not classified as a cold-water fishery, the classification
is 3E. the do standard at a maximum should be 4 mg/L because of the classification of the ditch.DWQ Response:
Upon review of this comment, the Division of Water Quality agrees with the City. The wasteload allocation for the facility was re-run with the appropriate classification of 3E. The Dissolved
Oxygen Limit for the facility has been changed to 4.0 mg/L. Comment 2:The ammonia limit was lowered from a high of 6 mg/L to a new high of 3.5 mg/L t in the low limit was lowered from
2.99 mg/L t to a new low of 2 mg/L t the statement of basis indicates the ammonia limit changed due to the change of sampling seasons to quarter from quarterly to irrigation/non-irrigation
season. if changing the sampling season changes the ammonia limits by that much please go back to the quarterly sampling for seasonal permitting purposes is not clear the wasteload if
the model accounts for the travel time from the treatment plant discharge to Spring Creek through this distant nitrification will continue to reduce the amount of ammonia in the ditch
in addition we have worked with the state in the past to help identify some additional spring water flow that enters the ditch prior to entering Spring Creek it is unclear in the wasteload
information if that water source has been neglectedDWQ Response: No changes have been made to the permit in response to this comment.Comment 3:TDS was given a limit in the proposed permit
according to the statement of basis this is because Spring Creek is listed on the 303(d) list for TDS impairment or understanding is the listing should require the state to complete
a TMDL related to the TDS parameter. The 303(d) list states that this is a low priority TMDL. Spring Creek currently has a site-specific TDS standard and if there are still TDS issues
the best alternative may be to address the site-specific standard. The city understands the need to gather data related to TDS it is also interested in collecting this data from the
treatment plant. However, we disagree that this should be included in the permit with a limit. The proposed TDS limit is significantly higher than the site-specific and water quality
standard which implies the city's current discharge is currently diluting the actual source of TDS therefore we ask that the TDS requirement in the permit be changed to sampling for
informational purposes only and monthly frequency to match other monitoring parameters.DWQ Response:The facility is correct in noting the Comment 4:Temperature monitoring was added to
the permit; the units on the temperature are listed as mg/L and Sample type is composite. Note H indicates this data is being gathered for a future TMDL or TMDLrevisions. The 2002 TMDLrecommended
that Spring Creek be delisted from the 303(d) list for temperature. Why was Spring Creek not delisted for temperature?
DWQ Response:
Upon review of this comment, the Division of Water Quality agrees with the City. The temperature sampling requirement is being removed from the draft permit. Comment 5:
Total residual chlorine is listed as a requirement for the reuse outfall. This should be removed from the permit because the treatment plant meets the disinfection requirement with the
use of UV lights. Note *l states that the 1 mg per liter residual is recommended and not a requirement. It is confusing to people looking at the permit that shows it as a requirement
for TRC of 1 mg/L and then has a note saying it is a recommendation. Please remove the requirement to avoid confusion.
DWQ Response:The option to use chlorine as an alternative disinfection method is added to permits to give permittees the operational flexibility in emergency situations. Upon review
of this comment, the Division of Water Quality will remove the requirement at the request of the City.Comment 6:The city requests a compliance schedule for each of the permit requirements
that are being restricted or added. The plant was designed based on a 2 MGD flow and loading from different constituents. Changing the permit limits May reduce the capacity of the treatment
facility especially as it gets closer to the design. It will take some time to evaluate how the permit changes will change the ability of the treatment facility to meet the new requirements.
Once that is determined it may take upgrades at the facility to meet the requirement and that will take additional time for Designing and implementation.DWQ Response:Upon review of this
comment, the Division of Water Quality will add a 1-year compliance schedule to the permit to meet the new permit limits. If additional time is needed beyond that, for planning and upgrades,
the existing permit can be opened and modified. Based upon the responses to these comments and changes to the permit, the permit will have to be sent back to public notice for 30 days.