DDW-2024-007597

May 15, 2024
Jack Lytle
Dutch John Town Water System
P.O. Box 219
Manila, Utah 84046Subject:Concurrence, Preliminary Design Report for Dutch John Membrane Plant (TP002); Dutch John Town Water System, System #05001, File #13036, SRF #3F1857
This is not Plan Approval for construction.Dear Jack Lytle:The Division of Drinking Water (the Division) received the Preliminary Design Report for an ultrafiltration surface water treatment
plant on April 17, 2024, from Aaron Averett, P.E. with Sunrise Engineering. The Division concurred with the Pilot Study Protocol on June 21, 2023.
It is our understanding that Dutch John Town Water System is planning to construct the Dutch John Membrane Plant (identified as TP002 in the Division’s database), which will treat water
from the Flaming Gorge Reservoir (WS001) and replace the existing Flaming Gorge WTP (TP001). The Dutch John Town Water System conducted a pilot study using ultrafiltration (UF) membrane
filtration along with granular activated carbon (GAC) filtration. The water source for the pilot testing was supplied through a temporary tap off the supply line to the existing Flaming
Gorge WTP.
The pilot study was performed from June 16, 2023, to September 4, 2023, to verify performance and suitability of a WesTech membrane filtration system using a Toray HFUG-2020AN UF module
followed by GAC filtration to confirm the ability to remove dissolved total organic carbon (TOC) from the membrane filtrate. The overall objectives of the study were as follows:
Demonstrate the effectiveness and reliability of the WesTechAltaPac membrane filtration system and performance of a Toray HFUG-2020AN membrane module.
Demonstrate the ability to operate sustainably at various flows from 24 to 35 gallons per minute (gpm) on the Flaming Gorge Reservoir (WS001) surface water source for 50 days. Finished
testing in the last weeks of the testing ran at a fixed normalized flux rate of 60 gallons per square foot per day (gfd).
Understand if there are significant fouling trends and demonstrate effective methods for cleaning and recovering membrane permeability.
Quantify volumes of chemicals and backwash/reject streams for full-scale estimates.
Quantify performance of treatment equipment by collecting operating parameters (flow, pressure, turbidity, flux rate, transmembrane pressure (TMP) and temperature).
Verify estimates for capital and O&M costs.
Demonstrate the technology can meet or exceed drinking water standards, including producing 0.10 NTU filtrate turbidity 95% of the time, passing direct integrity tests (DIT), and meeting
surface water log removal value (LRV) requirements.
Demonstrate the effectiveness and reliability of TOC removal through GAC filtration.
Investigate the fouling trends and demonstrate effective methods for cleaning and recovering membrane permeability.
Provide an opportunity for operators to become familiar with membrane filtration systems.
The pilot study results concluded the following:
Flux rates of 45 gfd and 60 gfd were tested to verify proposed full-scale design. System recovery averaged 97.3%.
TMPs were consistent throughout the study period, ranging from 6-13 psi while running at a flow rate between 24-35 gpm. Normalized flux ranged from 50-60 gfd through this range. Normalized
permeability averaged 5.97 gfd/psi. With these operational values, clean-in-place procedures were not required during the study period. CIPs are recommended on an annual to semi-annual
basis in the full scale systems to ensure removal of residual organic and inorganic material from the membranes.
Filtrate turbidity was an average of 0.035 NTU with 95% of the values <0.044 NTU. These values were achieved irrespective of feed water turbidity.
Maintenance cleanings were not done during the study as there was no significant upward trend in TMPs during testing. This indicated that solids accumulated during filter cycles were
effectively removed during the backwash process. Long term operation should include periodic maintenance cleans, around monthly, to ensure foulants are not allowed to accumulate over
time.
A 100% pass rate was achieved for the daily pressure decay testing. No bubbling was observed in the filtrate sight glass, indicating fiber integrity was maintained.
Log Removal Values (LRV’s) averaged 4.72, indicating suitability for treating surface water.
There were two GAC media types tested during the pilot study, each in a separate vessel, running in parallel. Flow through each GAC media was regulated to give an empty bed contact time
of 10 minutes. Grab samples were taken at various times during the study and sent to an outside lab for analysis. The results showed that both GAC media tested were effective at removing
the dissolved organics. The most effective was the AquaSorb3500 GAC media, which reduced TOC from 3.5 mg/l to close to 0 at the beginning of the study and removed 69% of the TOC at
the end of the study.
The preliminary design report establishes parameters for a full-scale membrane filtration facility that meets the requirements of Rule R309-530-8. We hereby concur with the Preliminary
Design Report for the proposed Dutch John Membrane Plant (TP002).
This concurrence is not Plan Approval to construct a full-scale treatment facility. Dutch John Town Water System shall submit plans and specifications of the full-scale plant, and a
complete Project Notification Form to the Division for approval prior to construction of the water treatment plant.
If you have any questions regarding this letter, you can contact me either by phone at [phone] or Michael Newberry, Engineering Manager, at [phone].
Sincerely,
Julie Cobleigh, P.E.
Environmental Engineer IIIJJC/mrn/mdbcc:Cindy Austreng, Tri-County Health Department, [e-mail] Hall, P.E., District Engineer, [e-mail] Averett,
Sunrise Engineering, [e-mail] Lytle, Dutch John Town Water System, [e-mail] Page, PhD, Division of Drinking Water, [e-mail] Cobleigh,
P.E., Division of Drinking Water, [e-mail] Pattee, Division of Drinking Water, [e-mail] 05001 13036 Preliminary Design Report Concur