DWQ-2025-004442

Official Draft Public Notice Version Month Day, year
The findings, determinations, and assertions contained in this document are not final and subject to change following the public comment period.
FACT SHEET
CASTLE VALLEY SPECIAL SERVICE DISTRICT
CASTLE DALE LAGOONS
RENEWAL PERMIT: DISCHARGE
UPDES PERMIT NUMBER: UT0023663
MINOR MUNICIPAL
FACILITY CONTACTSOperator Name:Castle Valley Special Service DistrictContact:Jacob Sharp, P.E.Position: District ManagerPhone Number:[phone]Permittee Name:Castle Valley Special
Service DistrictFacility Name:Castle Dale LagoonsMailing and Facility Address:Castle Valley Special Service District
P.O. Box 877
20 South 100 East,
Castle Dale, Utah 84513Telephone:[phone]Actual Address:Just Southeast of Castle Dale City off Hwy 10 in Emery County
DESCRIPTION OF FACILITY
Castle Valley Special Service District (CVSSD) operates the Castle Dale Lagoons (Castle Dale) domestic wastewater treatment facility, known as a Publicly Owned Treatment Works (POTW).
The facility is a four-cell, flow-thru lagoon system serving the population of Castle Dale and Orangeville Cities with no significant industrial users on the system. The first cell
is the largest followed by 3 smaller cells and then 3 alternating sand filters. The first cells are mechanically aerated with multiple aerators currently in service. The outfall is
located after the final lagoon cell and the 3 sand filters into Cottonwood Creek. The facility is an intermittent discharger based on seasonal loading and precipitation events with
discharges occurring 2-3 times each year on average. The lagoon has an average monthly design capacity of 0.7 million gallon per day (MGD).
On July 1, 2018 an effluent loading cap of 324 lbs/year for phosphorus went into effect. Effluent from Castle Dale has been in compliance with this loading cap.
SUMMARY OF CHANGES FROM PREVIOUS PERMIT
Total Dissolved Solids (TDS)
The TDS limits are being changed to be more consistent with the guidance and other UPDES Permits subject to Colorado River Basin Salinity Control Forum (CRBSCF) requirements. The loading
limit was indicated as 1 ton/day as a maximum, but the requirement is that over the year the average should not be greater than 1 ton/day.
DISCHARGE
DESCRIPTION OF DISCHARGE
Castle Dale has been reporting self-monitoring results on Discharge Monitoring Reports on a monthly basis. Castle Dale is an intermittent discharger based on seasonal loading and precipitation
events with discharges occurring 2-3 times each year on average. No discharge occurred during the previous permit life cycle. There have been no violations or discharges since 2005.OutfallDescription
of Discharge Point
001 Located at latitude 3911'30" and longitude 11100'30". The discharge is through sand filter beds and by pipe to Cottonwood Creek
RECEIVING WATERS AND STREAM CLASSIFICATION
When a discharge occurs, it is by gravity flow to Cottonwood Creek, which is part of the San Rafael and Colorado River systems.Cottonwood Creek is classified a Class 2B, 3C, and 4according
to Utah Administrative Code (UAC) R317-2-13:
Class 2B -- Protected for infrequent primary contact recreation. Also protected for secondary contact recreation where there is a low likelihood of ingestion of water or a low degree
of bodily contact with the water. Examples include, but are not limited to, wading, hunting, and fishing.
Class 3C -- Protected for nongame fish and other aquatic life, including the necessary aquatic organisms in their food chain.
Class 4 -- Protected for agricultural uses including irrigation of crops and stock watering.
TOTAL MAXIMUM DAILY LOAD (TMDL) REQUIREMENTS
Cottonwood Creek from the confluence with Huntington Creek to Highway 57 (UT14060009-011_00) was listed as impaired for pH and total dissolved solids according to the 303(d) list inUtah’s
2024 Integrated Report.
SITE SPECIFIC TOTAL DISSOLVED SOLIDS CRITERION
Per UAC R317-2-14, Cottonwood Creek from the confluence with Huntington Creek to U-57 hasa site-specific criterion for total dissolved solids (TDS) concentration of 3,500 mg/L that is
based upon the EPA approvedTMDL Price River, San Rafael River, and Muddy Creek TMDLs for Total Dissolved Solids, West Colorado Watershed Management Unit, Utah (MFG Inc., 2004).
BASIS FOR EFFLUENT LIMITATIONS
Limitations on total suspended solids (TSS), biochemical oxygen demand (BOD5), E. coli, pH and percent removal for BOD5 and TSS are based on current Utah Secondary Treatment Standards,
UAC R317-1-3.2. The oil and grease is based on best professional judgment (BPJ). Attached is a Wasteload Analysis for this discharge into the unnamed irrigation ditch. It has been
determined that this discharge will not cause a violation of water quality standards. An Antidegradation Level II review is not required since the Level I review shows that water quality
impacts are minimal. The permittee is expected to be able to comply with these limitations.
The TDS concentration limit of 3500 mg/L is based upon the approved TMDL study for the San Rafael River watershed (which includes Cottonwood Creek), in which a site specific criterion
was developed for TDS and can be found in Table A-12 of the document entitled, “Price River, San Rafael River, and Muddy Creek TMDLs for Total Dissolved Solids, West Colorado Watershed
Management Unit, Utah” (MFG Inc., 2004).
The TDS mass loading limitations are based upon Utah Water Quality Standards for concentration values and the Colorado River Basin Salinity Control Forum (CRBSCF) for mass loading values
when applicable as authorized in UAC R317-2-4. CRBSCF has established a policy for the reasonable increase of salinity for municipal discharges to any portion of the Colorado River
stream system that has an impact on the lower main stem. The CRBSCF Policy entitled “NPDES Permit Program Policy for Implementation of Colorado River Salinity Standards” (Policy), with
the most current version dated October 2020, states that the incremental increase in salinity shall be 400 mg/L or less, which is considered to be a reasonable incremental increase above
the flow weighted average salinity of the intake water supply. The permittee previously requested a salt loading (TDS) of 1 ton/day average, or 366 tons/year in lieu of the requirement
that the effluent not exceeding the culinary source water intake by more than 400 mg/L of TDS, which is in allowable under CRBSCF Policy.
Reasonable Potential Analysis
Since January 1, 2016, The Division of Water Quality (DWQ)has conducted reasonable potential analysis (RP) on all new and renewal applications received after that date. RP for this permit
renewal was conducted following DWQ’s September 10, 2015 Reasonable Potential Analysis Guidance (RP Guidance). There are four outcomes defined in the RP Guidance: Outcome A, B, C, or

D. These Outcomes provide a frame work for what routine monitoring or effluent limitations are required
Previously, a qualitative RP check was performed on the pollutants of concern to determine if there was enough data to perform a reasonable potential analysis on the outfall. Castle
Dale is a minor discharger with no known industrial dischargers and a low reasonable potential for toxics to be present in the effluent, therefore they have not been required to monitor
metals, and RP is not required to be run on their effluent at this time. If and when this changes, metals monitoring may be added to the permit.
The permit limitations are
Parameter
Effluent Limitations 1
Maximum Monthly Avg
Maximum Weekly Avg
Yearly
Average
Daily Minimum
Daily Maximum
Total Flow, MGD
0.7
-
-
-
-
BOD5, mg/L
BOD5 Min. % Removal
25
85
35
-
-
-
-
-
-
-
TSS, mg/L
TSS Min. % Removal
25
85
35
-
-
-
-
-
-
-
Dissolved Oxygen, mg/L
-
-
-
5.0
-
Total Ammonia (as N), mg/L
Summer (Jul-Sep)
Fall (Oct-Dec)
Winter (Jan-Mar)
Spring (Apr-Jun)
4.3
4.7
4.7
4.8
-
-

-
-
-
-
-
-
-
-
-
-
9.5
9.1
9.3
9.1
TDS, mg/L
-
-
-
-
3500
TRC, mg/L
-
-
-
-
0.024
Oil & Grease, mg/L
-
-
-
-
10.0
E. coli, No./100mL
126
157
-
-
-
pH, Standard Units
-
-
-
6.5
9
Mass Loading Limits
Parameter
Annual Avg. Daily
Annual Max
Total Phosphorus, lbs
-
-
324
-
-
TDS, Ton/Day 3
Tons/Year
1
-
-
-

-
366
-
-
-
-
See Definitions, Part VIII, for definition of terms.
Analytical results less than 0.06 mg/l will not be considered out of compliance with the permit. For purposes of calculating averages and reporting on the Discharge Monitoring Report
form, the following will apply:
Analytical values less than 0.02 mg/L shall be considered zero; and
Analytical values less than 0.06 mg/L and equal to or greater than 0.02 mg/L will be recorded as measured.
The salt loading (TDS) limit is 1 ton/day, or 366 tons/year in lieu of the requirement that the effluent not exceeding the culinary source water intake by more than 400 mg/L of TDS.
SELF-MONITORING AND REPORTING REQUIREMENTSThe following self-monitoring requirements have been modified to be consistent with the updated Monitoring and Sampling Frequency Guidance Document,
as described above. The permit requires reports to be submitted monthly and annually, as applicable, on Discharge Monitoring Report (DMR) forms due 28 days after the end of the monitoring
period. Effective January 1, 2017, monitoring results shall be submitted using NetDMR unless the permittee has successfully petitioned for an exception. Lab sheets for biomonitoring,
metals and toxic organics shall be attached to the DMRs.
Self-Monitoring and Reporting Requirements 1
Parameter
Frequency
Sample Type
Units
Total Flow 4, 5
Continuous
Recorder
MGD
BOD5, Influent 6
Effluent
Twice Monthly
Twice Monthly
Composite
Composite
mg/L
mg/L
TSS, Influent6
Effluent
Twice Monthly
Twice Monthly
Composite
Composite
mg/L
mg/L
E. coli
Twice Monthly
Grab
No./100mL
pH
Twice Monthly
Grab
SU
Total Ammonia (as N)
Twice Monthly
Composite
mg/L
DO
Twice Monthly
Grab
mg/L
TRC, mg/L, 7
Daily
Grab

mg/L
Oil & Grease 8
When Sheen Observed
Grab
mg/L
TDS, mg/L
Twice Monthly
Composite
mg/L
TDS, Average Daily Ton
Annually9
Composite
mg/L
TDS, Total Tons
Annually
Composite
mg/L
Orthophosphate (as P),6
Effluent
Monthly
Composite
mg/L
Total Phosphorus (as P),6
Influent
Effluent
Monthly
Monthly
Composite
Composite
mg/L
mg/L
Total Kjeldahl Nitrogen
TKN (as N),6
Influent
Effluent
Monthly
Monthly
Composite
Composite
mg/L
mg/L
Nitrate, NO36
Monthly
Composite
mg/L
Nitrite, NO26
Monthly
Composite
mg/L
See Definitions, Part VIII, for definition of terms.
Flow measurements of influent/effluent volume shall be made in such a manner that the permittee can affirmatively demonstrate that representative values are being obtained
If the rate of discharge is controlled, the rate and duration of discharge shall be reported
In addition to monitoring the final discharge, influent samples shall be taken and analyzed for this constituent at the same frequency as required for this constituent in the discharge
Total residual chlorine monitoring frequency is Daily, but only if the facility is chlorinating the effluent during monitoring period. If not chlorinating, a no data indicator (NODI)
code of 9 (Conditional Monitoring -Not Required This Period)
Oil & Grease sampled when sheen is present or visible. If no sheen is present or visible, reporta no data indicator (NODI) code of 9 (Conditional Monitoring -Not Required This Period)
For clarification, annual and quarterly monitoring requirements and limits are based on the calendar year.
BIOSOLIDS
The State of Utah has adopted the 40 Code of Federal Regulations (C.F.R.) §Part 503 federal regulations for the disposal of sewage sludge (biosolids) by reference. However, since this
facility is a lagoon, there is not any regular sludge production. Therefore 40 C.F.R. § 503 shall not apply at this time. In the future, if the sludge needs to be removed from the lagoons

and is disposed in some way, the DWQ must be contacted prior to the removal of the sludge to ensure that all applicable state and federal regulations are met
STORM WATER
MSGP coverage is required for Treatment Works treating domestic sewage or any other sewage sludge or wastewater treatment device or system, used in the storage, treatment, recycling,
and reclamation of municipal or domestic sewage, including lands dedicated to the disposal of sewage sludge that are located within the confines of the facility, with a design flow of
1.0 million gallons per day (MGD) or more, or required to have an approved pretreatment program under 40 C.F.R. § Part 403.
Because the design flow is less than 1.0 MGD a storm water UPDES permit is not required. Therefore, storm water permit provisions have not been included with the permit renewal. However,
at any time during the lifetime of this permit it may be re-opened and modified, following proper administrative procedures as per UAC R317-8, to include any applicable storm water provisions
and requirements.
Information onstorm water permit requirements can be found at http://stormwater.utah.gov
PRETREATMENT REQUIREMENTS
The permittee has not been designated for pretreatment program development because it does not meet conditions which necessitate a full program. The flow through the plant is less than
five (5) MGD, there are no categorical industries discharging to the treatment facility, industrial discharges comprise less than 1 percent of the flow through the treatment facility,
and there is no indication of pass through or interference with the operation of the treatment facility such as upsets or violations of the POTW's UPDES permit limits.
Although the permittee does not have to develop a State-approved pretreatment program, any wastewater discharges to the sanitary sewer are subject to Federal, State and local regulations.
Pursuant to section 307 of the Clean Water Act, the permittee shall comply with all applicable Federal General Pretreatment Regulations promulgated, found in 40 C.F.R. § 403 and the
State Pretreatment Requirements found in UAC R317-8-8.
An industrial waste survey (IWS) is required of the permittee as stated in Part II of the permit. The IWS is to assess the needs of the permittee regarding pretreatment assistance.
The IWS shall be submitted within sixty (60) days after the issuance of the permit. If an Industrial User begins to discharge or an existing Industrial User changes their discharge
the permittee shall resubmit an IWS no later than sixty days following the introduction or change as stated in Part II of the permit.
It is required that the permittee submit for review any local limits that are developed to the DWQ for review. If local limits are developed it is required that the permittee perform
an annual evaluation of the need to revise or develop technically based local limits for pollutants of concern, to implement the general and specific prohibitions 40 C.F.R. §, Part 403.5(a)
and Part 403.5(b). This evaluation may indicate that present local limits are sufficiently protective, may need to be revised, or should be developed.
BIOMONITORING REQUIREMENTS
A nationwide effort to control toxic discharges where effluent toxicity is an existing or potential concern is regulated in accordance with the Utah Pollutant Discharge Elimination System
Permit and Enforcement Guidance Document for Whole Effluent Toxicity Control (biomonitoring), dated February 2018. Authority to require effluent biomonitoring is provided in Permit
Conditions, UAC R317-8-4.2, Permit Provisions, UAC R317-8-5.3 and Water Quality Standards, UAC R317-2-5 and R317 -2-7.2.
The permittee is a minor municipal facility that will be infrequently discharging a minimal amount of effluent, in which toxicity is neither an existing concern, nor likely to be present.
Based on these considerations there is no reasonable potential for toxicity in the permittee’s discharge (per State of Utah Permitting and Enforcement Guidance Document for WET Control).
As such, there will be no numerical WET limitations or WET monitoring requirements in this permit. However, the permit will contain a toxicity limitation re-opener provision that allows
for modification of the permit should additional information indicate the presence of toxicity in the discharge.
PERMIT DURATIONIt is recommended that this permit be effective for a duration of five (5) years.Drafted and Reviewed byDaniel Griffin, Discharge Permit Writer, Biosolids, Reasonable
Potential AnalysisJennifer Robinson, PretreatmentLonnie Shull, BiomonitoringJordan Bryant, Storm WaterAmy Dickey, TMDL/Watershed ProtectionSuzan Tahir, Wasteload Analysis/ADRUtah Division
of Water Quality, [phone]PUBLIC NOTICE INFORMATION (to be updated after)Began: Month Day, 2025Ended: Month Day, 2025Comments will be received at: 195 North 1950 West PO Box 144870
Salt Lake City, UT 84114-4870The Public Notice of the draft permit was published on State of Utah and/or DWQ’s website for at least 30 days as required.During the public notice and comment
period provided under UAC R317-8-6.5, any interested person may submit written comments on the draft permit and may request a public hearing, if no hearing has already been scheduled.
A request for a public hearing shall be in writing and shall state the nature of the issues proposed to be raised in the hearing. All comments will be considered in making the final
decision and shall be answered as provided in UAC R317-8-6.12.ADDENDUM TO FACT SHEETDuring finalization of the Permit certain dates, spelling edits and minor language corrections were
completed. Due to the nature of these changes, they are considered minorchanges and the permit is not required to be re Public Noticed as provided in UAC R317-8-5.6(3)Responsiveness
Summary(Explain any comments received and response sent. Actual letters can be referenced, but not required to be included).
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ATTACHMENT 1
Industrial Waste Survey
This Page Intentionally Left BlankIndustrial Pretreatment Wastewater SurveyDo you periodically experience any of the following treatment works problems:foam, floaties or unusual colorsplugged
collection lines caused by grease, sand, flour, etc.discharging excessive suspended solids, even in the wintersmells unusually badwaste treatment facility doesn’t seem to be treating
the waste rightPerhaps the solution to a problem like one of these may lie in investigating the types and amounts of wastewater entering the sewer system from industrial users.An industrial
user (IU) is defined as a non-domestic user discharging to the waste treatment facility which meets any of the following criteria: 1.has a lot of process wastewater (5% of the flow
at the waste treatment facility or more than 25,000 gallons per work day.)Examples:Food processor, dairy, slaughterhouse, industrial laundry.2.is subject to Federal Categorical Pretreatment
Standards;Examples:metal plating, cleaning or coating of metals, blueing of metals, aluminum extruding, circuit board manufacturing, tanning animal skins, pesticide formulating or packaging,
and pharmaceutical manufacturing or packaging,3.is a concern to the POTW.Examples:septage hauler, restaurant and food service, car wash, hospital, photo lab, carpet cleaner, commercial
laundry.All users of the water treatment facility are prohibited from making the following types of discharges:1.A discharge which creates a fire or explosion hazard in the collection
system.2.A discharge which creates toxic gases, vapor or fumes in the collection system.3.A discharge of solids or thick liquids which creates flow obstructions in the collection system.4.An
acidic discharge (low pH) which causes corrosive damage to the collection system.5.Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will
cause problems in the collection system or at the waste treatment facility.6.Waste haulers are prohibited from discharging without permission. (No midnight dumping!)When the solution
to a sewer system problem may be found by investigating the types and amounts of wastewater entering the sewer system discharged from IUs, it’s appropriate to conduct an Industrial Waste
Survey.An Industrial Waste Survey consists of:Step 1: Identify Industrial UsersMake a list of all the commercial and industrial sewer connections.Sources for the list:business license,
building permits, water and wastewater billing, Chamber of Commerce, newspaper, telephone book, yellow pages.Split the list into two groups:domestic wastewater only-no further information
neededeveryone else (IUs)Step 2: Preliminary InspectionGo visit each IU identified on the “everybody else” list. Fill out the Preliminary Inspection Form during the site visit.Step
3: Informing the StatePlease fax or send a copy of the Preliminary inspection form (both sides) to:Jennifer RobinsonDivision of Water Quality288 North 1460 WestP.O. Box 144870Salt Lake
City, UT 84114-4870Phone: [phone]Fax:[phone]E-mail:[e-mail]:\WP\Pretreatment\Forms\IWS.doc
PRELIMINARY INSPECTION FORM

INSPECTION DATE / /
Name of Business Person Contacted
Address Phone Number
Description of Business
Principal product or service:
Raw Materials used:
Production process is: [ ] Batch [ ] Continuous[ ] Both
Is production subject to seasonal variation? [ ] yes[ ] no
If yes, briefly describe seasonal production cycle.
This facility generates the following types of wastes (check all that apply):
1. [ ] Domestic wastes(Restrooms, employee showers, etc.)
2. [ ] Cooling water, non-contact3. [ ] Boiler/Tower blowdown
4. [ ] Cooling water, contact5. [ ] Process
6. [ ] Equipment/Facility washdown7. [ ] Air Pollution Control Unit
8. [ ] Storm water runoff to sewer9. [ ] Other describe
Wastes are discharged to (check all that apply):
[ ] Sanitary sewer[ ] Storm sewer
[ ] Surface water[ ] Ground water
[ ] Waste haulers[ ] Evaporation
[ ] Other (describe)
Name of waste hauler(s), if used
Is a grease trap installed?YesNo
Is it operational?YesNo
Does the business discharge a lot of process wastewater?More than 5% of the flow to the waste treatment facility?YesNoMore than 25,000 gallons per work day?YesNo
Does the business do any of the following:[ ] Adhesives[ ] Car Wash[ ] Aluminum Forming[ ] Carpet Cleaner[ ] Battery Manufacturing[ ] Dairy[ ] Copper Forming[ ] Food
Processor[ ] Electric & Electronic Components[ ] Hospital[ ] Explosives Manufacturing[ ] Laundries[ ]Foundries[ ] Photo Lab[ ]Inorganic Chemicals Mfg. or Packaging[ ]
Restaurant & Food Service[ ] Industrial Porcelain Ceramic Manufacturing[ ] Septage Hauler[ ] Iron & Steel[ ] Slaughter House
[ ] Metal Finishing, Coating or Cleaning
[ ] Mining
[ ] Nonferrous Metals Manufacturing
[ ]Organic Chemicals Manufacturing or Packaging
[ ] Paint & Ink Manufacturing
[ ] Pesticides Formulating or Packaging
[ ] Petroleum Refining
[ ] Pharmaceuticals Manufacturing or Packaging
[ ] Plastics Manufacturing
[ ] Rubber Manufacturing
[ ] Soaps & Detergents Manufacturing
[ ] Steam Electric Generation
[ ] Tanning Animal Skins
[ ] Textile Mills
Are any process changes or expansions planned during the next three years? YesNo
If yes, attach a separate sheet to this form describing the nature of planned changes or expansions.
Inspector
Waste Treatment Facility
Please send a copy of the preliminary inspection form (both sides) to:
Jennifer Robinson
Division of Water Quality
P. O. Box 144870
Salt Lake City, Utah 84114-4870
Phone:[phone]
Fax:[phone]E-Mail:[e-mail]
Industrial User
Jurisdiction
SIC Codes
Categorical Standard Number
Total Average Process Flow (gpd)
Total Average Facility Flow (gpd)
Facility Description
1

2
3
4
5
6
7
8
9
10
11
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ATTACHMENT 2
Wasteload Analysis
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ATTACHMENT 3
Reasonable Potential Analysis
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REASONABLE POTENTIAL ANALYSIS
Water Quality has worked to improve our reasonable potential analysis (RP) for the inclusion of limits for parameters in the permit by using an EPA provided model. As a result of the
model, more parameters may be included in the renewal permit. A Copy of the Reasonable Potential Analysis Guidance (RP Guide) is available at water Quality. There are four outcomes
for the RP Analysis. They are;
Outcome A:A new effluent limitation will be placed in the permit.
Outcome B:No new effluent limitation. Routine monitoring requirements will be placed or increased from what they are in the permit,
Outcome C:No new effluent limitation. Routine monitoring requirements maintained as they are in the permit,
Outcome D:No limitation or routine monitoring requirements are in the permit.Castle Dale is a minor discharger with no known industrial dischargers with a low reasonable potential for
toxics to be in the effluent, therefore they are not required to monitor metals, and RP is not required to be run on their effluent at this time. If and when this changes, metals monitoring
may be added to the permit.