DWQ-2025-002570

UPDES INSPECTION SUMMARY and FINDINGS
Permittee Name:Tremonton City Wastewater TreatmentFacility
Facility Name:TremontonPOTW
Inspection Type:Compliance Evaluation Inspection + Biosolids Inspection
Permit Number: UT0020303 + UTL-020303
Start Date and Time: 13 March 2025, 09:50 AM
End Date and Time: 13 March 2025, 11:30 AM
Facility Location: 300 East 1200 South Tremonton, Utah
OVERVIEW
Jeff Studenka and Dan Griffin of the Division of Water Quality (DWQ) met with Paul Fulgham, Tremonton Public Works Director,and Carl Mackley, Assistant Public Works Director, representing
the Tremonton Wastewater Treatment Facility (Facility) to perform a biennial UPDES Permit Compliance Evaluation Inspection (CEI) and Biosolids inspection. The purpose and scope of the
inspection was explained, DWQ credentials were presented, the DWQ inspection checklist was completed, and a full facility tour was conducted. Although there were no deficiencies noted
from the last inspection (FY23 CEI) that required follow up at this time, there were recommendations included in the last CEI report that werereviewed and addressed previously.
PERMIT INFORMATION
Discharge
Receiving Waters:Malad River
Permitted Outfalls:001
Permit Issuance Date:06/01/2024
Permit Expiration Date:09/30/2028
Treatment Design Flow:2.0 MGD
Biosolids
The permit includes provisions for Biosolids in Part III. The Facility has a Biosolids Program, which is inspected more thoroughly during Biosolids inspections. This was discussed as
part of the inspection activities. Information regarding the Biosolids inspection can be found in the Biosolids sections of this report.
Pretreatment
The permit includes provisions for Pretreatment requirements in Part II. The Facilitydoes not currently have an approved Pretreatment Publicly Owned Treatment Works Program. This is
inspected more thoroughly during separate DWQ Pretreatment inspections. Therefore, this was not discussed further as part of the this CEI.
Wastewater Collection System
TheFacility operatesand maintains the collection system. This was not discussed further as part of the CEI other than the MWPP information portion of the CEI Checklist. Requirements
regarding overseeing the collection system are included in the General Permit issued by DWQ Permit No. UTG580000. Additional information regarding this permit can be found at the following
website:
https://deq.utah.gov/water-quality/utah-sewer-management-program-usmp
BACKGROUND/PROCESS INFORAMTION
Wastewater Process:The wastewater treatment process upon influent flows into the Facility consists of a Headworks building with micro-screen and grit filter → primary clarifier (andSalsnes
filter currently not in use) → 2 Aerotor basins (4 Aerotors each) ↔ Anoxic basin → 2 secondary clarifies → sand filters (as needed) → ultra violet (UV) disinfection → effluent discharge
(001) to Malad River.
Biosolids Process:(primary and secondary clarifiers) → aerated digesters→ screw-press → compost pad → Class A distribution.
INSPECTION ACTIVITIES
Flow Measurements:Flow is continuously measured for both the influent and the effluent. Influent flow is measured with an inline Siemens electromagnetic flow meter.The effluent flow
is measured using a pressure transducer located at the effluent weir, which measures the head and calculates the flow. Both flow measurements are sent to the SCADA system readout in
the main building near the lab. This is the primary method of measuring flow for UPDES reporting purposes. The effluent flow can also be measured with the 24-inch rectangular weir
and staff gauge, which is used as a regular calibration check on the flow data sent to the SCADA system. Monthly comparisons are conducted by the facility of the primary vs. secondary
effluent flow measurements, which are typically within the 10% difference requirement as recorded.
Self-Monitoring Program:Discharge Monitoring Report (DMR) data for the end of 2024 were reviewed and compared to the monthly operation summary report and laboratory bench sheets. DMRs
are submitted monthly via NetDMR as required.Both composite and grab samples are conducted as required in the UPDES Permit. Hach auto-samplers are utilized for composite samples for
both the influent and effluent monitoring as required, including biomonitoring. The auto-samplers are located at both the influent and effluent monitoring stations and were observed
to be functioning properly at the time of the inspection, however at the time of the inspection only the Effluent auto-sampler included a dedicated thermometer inside the refrigerator
while the Influent auto-sampler thermometer was missing. This was immediately corrected by the Facility within 24-hours of the CEI as verified via email to DWQ indicating.
Samples are analyzed at the on-site NELAC certified laboratory for pH, TSS, BOD, E-coli, ammonia as nitrogen, total phosphorous and associated nutrient parameters. When a pH sample is
taken as required by the permit, it is immediately analyzed onsite within the 15-minute holding time requirement.Samples for metals, including cyanide, and toxic organics are sent to
Chemtech Ford in Sandy, Utah for analyses. Whole effluent toxicity (WET) biomonitoring samples are sent via FedEx or hand-delivered same day to WET, Inc. Labs in American Fork, Utah
on a quarterly basis with alternating species as required by the permit. No WET toxicity issues have been detected over the past several years. Information provided in NetDMR was consistent
with the data reported on the laboratory bench sheets for the months reviewed in 2024. Holding times were consistently met, and the appropriate numbers of samples were collected using
the methods specified in the permit.
Regarding 2024 quarterly WET sample temperatures as received by the lab, it was noted that temperatures sometimes exceeded the 6℃ recommended EPA criteria as documented on the lab chain
of custody forms, but they all did arrive with ice packs for preservation using next day or same day delivery services. It was recommended that all samples are packed with adequate ice
or ice packs to consistently meet the target preservation criteria.
Facility Site Walk & Tour: A full facility walking tour was conducted following the treatment process from influent to effluent. Changes since the previous CEI include the new Trojan
UV system upgrade which was completed in 2024, as well as withthe Salsnes filtration system, which is no longer needed and has been removed from service. Safety features and good housekeeping
practices were observed throughout the plant as appropriate. At the time of the inspection, the facility appeared to be well maintained and operated with no deficiencies observed and

no concerns noted. Photos from the facility walk through are included below.
Biosolids Inspection:The biosolids inspection was conducted in conjunction with the CEI at the facility. The facility has added a second screw press and conveyor/hopper to facilitate
the movement of the biosolids to trucks for transporting to composting. They addition of the conveyor has eliminated the need to use a loader to collect the biosolids that used to pile
up on the floor and load them into a dump truck. This has improved the air quality in the solids dewatering building as well as improved the cleanliness of the building. The facility
has 2 aerated digestors. Both were built with static lids, but years ago the lid was taken off of the north one. They do not operate the digestors to digest biosolids or collect the
gas for power generation, so they are currently acting like air mixed biosolids storage basins. In the near future they intend to have the lid of the south digestor removed to make servicing
it safer and easier.
DISCHARGE INFORMATION
At the time of the inspection, the final effluent discharge was observed to be mostly clear at both the effluent weir and Outfall 001 locations. There was no odor, excessive discoloration
or foaming, or other issues noted at the time of the inspection. The receiving waters of the Malad River were also observed and with no issues identified. Photos of the effluent discharge
are included below.
DEFICIENCIESNone observed.
RECOMMENDATIONS
Ensure the dedicated thermometers remain in the auto-sampler refrigerators as appropriate.
Ensure that all WET samples are packed with adequate ice or ice packs to consistently meet the target preservation criteria.
Continue keeping DWQ informed of any changes to site conditions and operations in regards to future Facility expansion and UPDES Permit requirements.
PHOTO LOG
Photo No. 1
Date:3-13-2025
Description:Onsite Lab.
Photo No. 2
Date:3-13-2025
Description: Inside headworks building.
Photo No. 3
Date:3-13-2025
Description: Influent flow meter.
Photo No. 4
Date:3-13-2025
Description:Influent auto-sampler.
Photo No. 5
Date:3-13-2025
Description:SCADA monitoring system with influent and effluent flows in real time.
Photo No. 6
Date:3-13-2025
Description:Aerotors with final clarifiers in background.
Photo No. 7
Date:3-13-2025
Description:Anoxic basins for nutrient removal with primary clarifier in background.
Photo No. 8
Date:3-13-2025
Description:Sand filtration building, as needed. Currently not in use.
Photo No. 9
Date:3-13-2025
Description:UV disinfection unit, new in 2024.
Photo No. 10
Date:3-13-2025
Description: Effluent Weir post UV and just prior to Outfall 001 discharges.
Photo No. 11
Date:3-13-2025
Description:Effluent auto-sampler located near theeffluent weir.
Photo No. 12
Date:3-13-2025
Description: Outfall 001 discharging into the Malad River.
Photo No. 13
Date:3-13-2025
Description:Screw-presses, conveyor and hopper inside biosolids building.
Photo No. 14
Date:3-13-2025
Description: Inside biosolidsbuilding.