Draft NPDES and SDS Permit to City of Detroit Lakes ......screens with six millimeter openings, a new vortex grit chamber, two rotary mechanical fine screens with two millimeter openings,

National Pollutant Discharge Elimination System/State Disposal System

MN0020192 Permittee: City of Detroit Lakes

Facility name: Detroit Lakes Wastewater Treatment Facility

Receiving water: Unnumbered Wetland – (Class 2D, 3D, 4C, 5, 6 water) to

St Clair Lake – (Class 2B, 3C, 4A, 4B, 5, 6 water)

City: Detroit Lakes County: Becker

Issuance date: February 06, 2014

Expiration date: January 31, 2019

Modification date: TBD

The state of Minnesota, on behalf of its citizens through the Minnesota Pollution Control Agency (MPCA), authorizes the Permittee to operate a disposal system at the facility named above and to discharge from this facility to the receiving water named above, in accordance with the requirements of this permit. The goal of this permit is to reduce pollutant levels in point source discharges and protect water quality in accordance with the U.S. Clean Water Act, Minnesota statutes and rules, and federal laws and regulations. This permit is effective on the issuance date identified above. This permit expires at midnight on the expiration date identified above.

Signature: [Type e-Signature] This document has been electronically signed. for the Minnesota Pollution Control Agency

Paul C. Scheirer Supervisor Northeast/Northwest Regional Unit Municipal Division

Submit eDMRs Questions on this permit? Submit via the MPCA Online Services Portal at For eDMR and other permit reporting issues, contact: https://netweb.pca.state.mn.us/private/ Jennifer Satnik, 651-757-2692

Submit other WQ reports to: For specific permit requirements please refer to: Attention: WQ Submittals Center Joe Braun, 218-846-8126 Minnesota Pollution Control Agency 520 Lafayette Road North Wastewater Permit Program general questions, contact: St. Paul, MN 55155-4194 MPCA, 651-282-6143 or 1-800-657-3938.

https://netweb.pca.state.mn.us/private/

Table of Contents

Page

1. Permitted facility description ....................................................................................................................................... 3 2. Location map of permitted facility ............................................................................................................................... 5 3. Flow diagram ................................................................................................................................................................ 7 4. Summary of stations and station locations.................................................................................................................. 8 5. Permit requirements .................................................................................................................................................... 9 6. Submittal action summary ......................................................................................................................................... 40 7. Limits and monitoring ................................................................................................................................................ 47

8. Appendix A ………………………………………………………………………………………………………………………………………………………….70

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 3 of 70 Permit modified: 1. Permitted facility description The Detroit Lakes Wastewater Treatment Facility (Facility) is located at 1150 Willow St W, Detroit Lakes, Minnesota 56502, Becker County. Major components of the facility include:

1 Collection System with gravity and/or Pressure Sewer 1 Bar Screen – mechanical 1 Pumping (Lift) Station 1 Grit Removal Unit 2 Primary Clarifiers 2 Trickling Filters 1 Secondary Clarifier 1 Polishing Pond without aeration (3 acres) 1 Polishing Pond without aeration (25 acres) Effluent Pumping Phosphorus Removal – chemical 2 Filters – sand with backwash 1 Chlorination Unit 19 Rapid Infiltration Basins (21.75 acres total) 4 Spray Irrigations – agricultural (53.97 acres) 2 Anaerobic Solids Digesters 1 Biosolids Storage Tank (137,000 gallons) Biosolids Land Application

The existing treatment system consists of 60 lift stations, a bar screen, aerated grit removal, two primary clarifiers, two trickling filters, a secondary settling tank, a 3-acre polishing pond (4.75 day detention time), a 25-acre polishing pond (18 day detention time), a chemical precipitation plant, a chlorination unit, two dual media filters, 19 rapid infiltration basins (RIBs) (21.75 acres total), four spray irrigation sites (54 acres total), a 450-foot long effluent dispersion ditch, a primary and secondary sludge digester, three sludge storage tanks (326,486 gallons total capacity), and a stand-by generator. Fourteen ground water monitoring wells are installed at the Facility for monitoring the irrigation and rapid infiltration basin sites. The Facility discharges (SD002) to the dispersion ditch that discharges to a peat bog and then to St. Clair Lake. The Facility is designed to treat an average annual influent flow of 1.64 million gallons per day (mgd) and an average wet weather flow of 2.02 mgd with a 5-day carbonaceous biochemical oxygen demand (CBOD5) strength of 320 milligrams per liter (mg/L). From approximately April 15 to December 31, the treated effluent may be applied to the rapid infiltration basins (RIBs). From approximately May 15 to October 31, the treated effluent is applied to the four spray irrigation fields. RIBs may be used concurrently with the spray irrigation system. The Facility is further described in plans and specifications on file with the MPCA (WPC 3673 stated December 29, 1961, and Permit #8524 dated July 15, 1974) and in engineering reports prepared by Larson and Associates (Ulteig Engineers, Inc.), Detroit Lakes, Minnesota. The Facility was expanded and upgraded in 1995 and 1996. Plans and specifications for the upgraded Facility were prepared by Larson-Peterson and Associates (Ulteig Engineers, Inc.), Detroit Lakes, Minnesota and are on file with the MPCA.

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 4 of 70 Permit modified: PROPOSED UPGRADED FACILITY CHANGES: The application documents indicate the existing treatment Facility will be upgraded to include two rotary mechanical screens with six millimeter openings, a new vortex grit chamber, two rotary mechanical fine screens with two millimeter openings, two equalization tanks, an activated sludge system with no clarifier (the activated sludge system will have anaerobic, anoxic and oxic zones), a four-train membrane bio-reactor (MBR) system that specializes in the advanced removal of nutrients, and ultraviolet (UV) disinfection as backup disinfection process. The existing two anaerobic digesters will be converted to aerobic digesters with sludge pre-thickening. The project also includes dewatering by centrifuge and cake storage of biosolids. The proposed upgraded Facility will result in an Average Wet Weather (AWW) design flow increase to 2.21 mgd. The Average Dry Weather Flow will be expanded to 1.86 mgd. The upgraded Facility will utilize their currently permitted surface discharge location (SD002) as the location for the total Facility effluent. Upon initiation of operation, the Facility will abandon the currently permitted spray irrigation fields, RIBs, and will decommission both of the existing polishing ponds. Anti-degradation and Anti-backsliding language applicable to all NPDES/SDS permits: Changes to the facility may result in an increase in pollutant loading to surface waters or other causes of degradation to surface waters. If a change to the facility will result in a net increase in pollutant loading or other causes of degradation that exceed the maximum loading authorized through conditions specified in the existing permit, the changes to the facility are subject to antidegradation requirements found in Minn. R. 7050.0250 to 7050.0335. This Permit also complies with Minn. R. 7053.0275 regarding anti-backsliding. Any point source discharger of sewage, industrial, or other wastes for which a NPDES permit has been issued by the MPCA that contains effluent limits more stringent than those that would be established by Minn. R. 7053.0215 to 7053.0265 shall continue to meet the effluent limits established by the permit, unless the permittee establishes that less stringent effluent limits are allowable pursuant to federal law, under section 402(o) of the Clean Water Act, United States Code, title 33, section 1342.]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 5 of 70 Permit modified: 2. Location map of permitted facility

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 6 of 70 Permit modified:

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 7 of 70 Permit modified: 3. Flow diagram

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 8 of 70 Permit modified: 4. Summary of stations and station locations

Station Type of station Local name PLS location GW 001 Well, Downgradient MW-1 T139N, R41W, S32, NE Quarter of the SE Quarter

of the SE Quarter GW 002 Well, Upgradient MW-2 T139N, R41W, S32, NE Quarter of the NW Quarter

of the NE Quarter GW 003 Well, Downgradient MW-3 T139N, R41W, S29, SE Quarter of the NW Quarter

of the SE Quarter GW 004 Well, Upgradient MW-4 T139N, R41W, S29, NE Quarter of the SW Quarter

of the SE Quarter GW 005 Well, Upgradient MW-5 T139N, R41W, S29, NE Quarter of the SE Quarter

of the NE Quarter GW 006 Well, Downgradient MW-6 T139N, R41W, S29, SE Quarter of the NE Quarter

of the NE Quarter GW 007 Well, Downgradient MW-7 T139N, R41W, S29, SE Quarter of the NE Quarter

of the SE Quarter GW 009 Well, Downgradient MW-9 T139N, R41W, S28, SW Quarter of the SW Quarter

of the NW Quarter GW 010 Well, Downgradient MW-10 T139N, R41W, S28, SW Quarter of the SW Quarter

of the SW Quarter GW 011 Well, Downgradient MW-11 T139N, R41W, S33, NW Quarter of the NW

Quarter of the NE Quarter GW 012 Well, Downgradient MW-12 T139N, R41W, S33, NW Quarter of the NW

Quarter of the NW Quarter GW 013 Well, Downgradient MW-13 T139N, R41W, S33, NW Quarter of the NW

Quarter of the SW Quarter GW 014 Well, Downgradient MW-14 T139N, R41W, S33, NW Quarter of the SW

Quarter of the SW Quarter GW 015 Well, Downgradient MW-15 T139N, R41W, S33, SW Quarter of the NE Quarter

of the NW Quarter LA 319 Application Site, Spray with

Soils Tests Crop and Soils-Irrigation Site #1 & 2

T139N, R41W, S29, NE Quarter of the NE Quarter

LA 320 Application Site, Spray with Soils Tests

Crop and Soils-Irrigation Site #3 & 4

T139N, R41W, S29, SE Quarter of the NE Quarter

SD 002 Effluent To Surface Water Chem PPT Plant to Unnamed Wetland

T139N, R41W, S33, SW Quarter of the NW Quarter

WS 002 Influent Waste Influent Waste Stream T139N, R41W, S33, NE Quarter WS 003 Internal Waste Stream Pond Effluent to Irrigation

Sites and RIBs T139N, R41W, S33

WS 004 Intermediate: WW to Land Pond Effluent to RIBs T139N, R41W, S33, NW Quarter of the NW Quarter

WS 005 Intermediate: WW to Land Spray Sites #1 & 2 - 31.13 acres T139N, R41W, S29, NE Quarter of the NE Quarter WS 006 Intermediate: WW to Land Spray Sites #3 & 4 - 22.84 acres T139N, R41W, S29, SE Quarter of the NE Quarter WS 007 Internal Waste Stream Mechanical Plant to Polishing

Ponds T139N, R41W, S33, SE Quarter of the NE Quarter

WS 008 Internal Waste Stream Polishing Pond to Chem. PPT Plant

T139N, R41W, S29, NW Quarter of the NW Quarter

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 9 of 70 Permit modified: 5. Permit requirements GW 001 Well,

Downgradient

Groundwater Well: Monitoring Requirements 5.1.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.1.2 The Permittee shall submit monitoring results in accordance with the limits and monitoring

requirements for this station. If conditions are such that no sample can be acquired, the Permittee shall report "No Flow" or "No Discharge" on Discharge Monitoring Report (DMR) and shall add a Comments attachment to the DMR detailing why the sample was not collected. [Minn. R. 7001.0150, Subp. 2(B)]

Facility Specific Requirements 5.2.3 The parameters required to be monitored for in this station have been assigned a "Phase 1" in the

limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility. [Minn. R. 7001]

GW 002 Well,

Upgradient






GW 003 Well,

Downgradient






Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 10 of 70 Permit modified: GW 004 Well,

Upgradient





limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and abandonment of the groundwater wells. [Minn. R. 7001]

GW 005 Well,

Upgradient






GW 006 Well,

Downgradient






GW 007 Well,

Downgradient

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 11 of 70 Permit modified: Groundwater Well: Monitoring Requirements 5.13.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month





GW 009 Well,

Downgradient






GW 010 Well,

Downgradient






GW 011 Well,

Downgradient

Groundwater Well: Monitoring Requirements

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 12 of 70 Permit modified: 5.19.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month





GW 012 Well,

Downgradient






GW 013 Well,

Downgradient






GW 014 Well,

Downgradient


following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 13 of 70 Permit modified: 5.25.2 The Permittee shall submit monitoring results in accordance with the limits and monitoring




GW 015 Well,

Downgradient






SD 002 Effluent To

Surface Water

Surface Discharge: Class A Major Facility Effluent Requirements 5.29.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)] 5.29.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.29.3 Samples for Station SD002 shall be collected from the final outlet control structure which is the

effluent pipeline. The Total Residual Chlorine, 0.038 milligram per liter (mg/L) limit has been assigned "Phase 1" in the limits and monitoring table. Monitoring for this parameter is required from the effective date of this modification through the time of initiation of operation of the upgraded facility. The total phosphorus, 198 kilogram per year (kg/yr) limit has been assigned a "Phase 2" in the limits and monitoring table. This total phosphorus limit becomes effective at the time of initiation of operation of the upgraded facility. [Minn. R. 7001]

5.29.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring requirements for this station. If conditions are such that no sample can be acquired, the Permittee shall report "No Flow" or "No Discharge" on Discharge Monitoring Report (DMR) and shall add a Comments attachment to the DMR detailing why the sample was not collected. [Minn. R. 7001.0150, Subp. 2(B)]

Priority Pollutant Requirements

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 14 of 70 Permit modified: 5.30.5 The Permittee shall monitor the effluent three times in the life of the permit for the following

specified priority pollutants. Sampling events shall not be less than one year apart. Monitoring shall be for the organic priority pollutants identified under the volatile, acid, base/neutral, and pesticide fractions using EPA methods 624, 625 and 608 (40 CFR Part 136, October 25, 1984) as listed in Table II of 40 CFR Part 122, Appendix D or any updates to those methods. The following priority pollutant total metals shall also be monitored using either EPA method 200.8 or their corresponding graphite furnace method found in Table IB of 40 CFR Part 136 or any updates to those methods: antimony, arsenic, beryllium, cadmium, chromium, copper, lead, nickel, selenium, silver, thallium, and zinc. In addition, the Permittee shall monitor for Total Cyanide (EPA method 335), Total Phenolic Compounds (EPA method 420), and Hardness (total as CaCO3) (EPA method 130). Total Mercury shall be monitored by EPA method 1631 or any update to this method, if not already required by the permit. [Minn. R. 7001]

5.30.6 The Permittee shall submit the results of the first sampling event no later than three years prior to the expiration date of this permit. [Minn. R. 7001]

5.30.7 The Permittee shall submit the results of the second sampling event no later than two years prior to the expiration date of this permit. [Minn. R. 7001]

5.30.8 The Permittee shall submit the third priority pollutant monitoring report: Due 365 calendar days before Permit Expiration Date. (365 days = 1 year). [Minn. R. 7001]

5.30.9 All Quality Assurance/Quality Control (QA/QC) information shall be included with each set of priority pollutant results. [Minn. R. 7001]

Chronic Toxicity Requirements 5.31.10 General Requirements. [Minn. R. 7001] 5.31.11 The Detroit Lakes WWTF is in the middle of a Toxicity Reduction Evaluation (TRE) and a Toxicity

Identification Evaluation (TIE). Corrections will be made as a result of the TRE. Corrections and upgrades will also be made to the plant because of on-going issues with the stabilization ponds and a water quality based effluent limit for phosphorus. Because of the changes due to these issues, Environmental Assessment and Outcomes (EAO) staff did not perform a reasonable potential analysis for chronic WET testing related to this facility. Because this Facility is in a TRE, a WET limit of 1.0 TUc is being set. However, this limit will not go into effect until after the TRE is completed and upgrades have been done to the Facility according to the TRE findings. As that time, the Detroit Lakes WWTF will do quarterly chronic WET testing for the first year and then annual chronic WET testing will be required during the remainder of the permit. Upon initiation of operation of the upgraded Facility, the Chronic WET testing and reporting requirements will be updated. [Minn. R. 7001]

5.31.12 Whole Effluent Toxicity Requirement Definitions. [Minn. R. 7001] 5.31.13 "Chronic Whole Effluent Toxicity (WET) Test is a static renewal test conducted on an exponentially

diluted series of effluent. The purpose is to calculate appropriate biological effect endpoints (NOEC or IC25), specified in the referenced chronic manual. A statistical effect level less than the Receiving Water Concentration (RWC) constitutes a positive test for chronic toxicity. The RWC equals the 100 percent effluent concentration or 1 TUc. [Minn. R. 7001]

5.31.14 "Chronic toxic unit (TUc)" is the reciprocal of the effluent dilution that causes no unacceptable effect on the test organisms by the end of the chronic exposure period. For example, a TUc equals [7Q10flow (mgd) + effluent average dry weather flow (mgd)]/[effluent average dry weather flow (mgd)]. [Minn. R. 7001]

5.31.15 "Test" refers to an individual species. [Minn. R. 7001] 5.31.16 "Test Battery" consists of WET testing of all test species for the specified test. For chronic WET

testing, all test species includes fathead minnows and Ceriodaphnia Dubia. [Minn. R. 7001] Facility Specific Requirements

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 15 of 70 Permit modified: 5.32.17 At the time of initiation of operation of the upgraded facility, the Permittee has agreed to accept

frozen mass limits on the following parameters: total suspended solids, 5-day carbonaceous biochemical oxygen demand (CBOD5), and total phosphorus. By accepting frozen mass limits, an anti-degradation review is not needed as there will be no net increase in mass loading for these parameters. [Minn. R. 7001]

WS 002 Influent Waste Waste Stream: Class A Major Facility Influent Requirements 5.33.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)] 5.33.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.33.3 Influent grab and composite samples for Station WS002 at the existing Facility shall be collected

immediately following the bar screen. Upon initiation of operation of the upgraded Facility, samples for Station WS002 will need to be collected immediately upstream of the Facility. [Minn. R. 7001]

5.33.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring requirements for this station. If conditions are such that no sample can be acquired, the Permittee shall report "No Flow" or "No Discharge" on Discharge Monitoring Report (DMR) and shall add a Comments attachment to the DMR detailing why the sample was not collected. [Minn. R. 7001.0150, Subp. 2(B)]

WS 003 Internal Waste

Stream

Waste Stream: Spray Irrigation Pond Effluent Requirements 5.34.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.34.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.34.3 Samples for Station WS003 shall be collected prior to discharge to the rapid infiltration basins and

the irrigation sites. [Minn. R. 7001.0150, Subp. 2(B)] 5.34.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring



limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of the spray irrigation sites and rapid infiltration basins. [Minn. R. 7001]

WS 004 Intermediate:

WW to Land

Facility Specific Limit and Monitoring Requirements 5.36.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.36.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.36.3 Flow measurements for Station WS004 shall be collected during discharge to the rapid infiltration

basins. [Minn. R. 7001.0150, Subp. 2(B)] 5.36.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring


Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 16 of 70 Permit modified: Facility Specific Requirements 5.37.5 The parameters required to be monitored for in this station have been assigned a "Phase 1" in the

limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of use of the rapid infiltration basins. [Minn. R. 7001]


WW to Land

Waste Stream: Spray Irrigation to Spray Site Requirements 5.38.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.38.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.38.3 Flow measurements for Station WS005 shall be collected during discharge to irrigation sites #1 and

#2. [Minn. R. 7001] 5.38.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring



limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of use of the spray irrigation sites. [Minn. R. 7001]


WW to Land

Waste Stream: Spray Irrigation to Spray Site Requirements 5.40.1 The Permittee shall submit a monthly DMR: Due by 21 days after the end of each calendar month

following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.40.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.40.3 Flow measurements for Station WS006 shall be collected during discharge to irrigation sites #3 and

#4. [Minn. R. 7001] 5.40.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring



limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of use of the spray irrigation sites. [Minn. R. 7001]


Stream


following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.42.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 17 of 70 Permit modified: 5.42.3 Samples for Station WS007 shall be collected at the effluent pumping station after the chlorine

contact tank and prior to the 3-acre pond cell. [Minn. R. 7001] 5.42.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring


Facility Specific Requirements 5.43.5 Flow from the mechanical plant to the polishing ponds shall be calculated by taking the total influent

to the WWTF and subtracting the biosolids removed. [Minn. R. 7001] 5.43.6 The parameters required to be monitored for in this station have been assigned a "Phase 1" in the

limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of the internal waste stream from the existing mechanical plant to the polishing ponds. [Minn. R. 7001]


Stream


following permit issuance. [Minn. R. 7001.0150, Subp. 2(B)], Phases: Phase 1 5.44.2 Sampling Location. [Minn. R. 7001.0150, Subp. 2(B)] 5.44.3 Flow measurements for Station WS008 shall be collected after the 25-acre pond cell and prior to the

chemical precipitation plant. [Minn. R. 7001.0150, Subp. 2(B)] 5.44.4 The Permittee shall submit monitoring results in accordance with the limits and monitoring



limits and monitoring table. Monitoring for these parameters are required from the effective date of this modification through the time of initiation of operation of the upgraded facility and discontinuation of the internal waste stream from the polishing ponds to the chemical precipitant plant. [Minn. R. 7001]

MN0020192 Detroit Lakes

WWTP

Groundwater Station General Requirements 5.46.1 Analysis Requirements. [Minn. R. 7001] 5.46.2 If monitoring is required for Dissolved Oxygen, pH, Specific Conductance, Temperature and Total

Residual Chlorine, the analyses shall be conducted within 15 minutes of sample collection. [Minn. R. 7001]

5.46.3 Monitoring Wells. [Minn. R. 7001] 5.46.4 The Permittee shall install, maintain and abandon groundwater monitoring wells according to the

Minnesota Water Well Construction Code, Minnesota Rules, ch. 4725. Damaged or improperly constructed monitoring wells shall be repaired or properly abandoned and replaced. Information on licensed water well contractors is available from the Minnesota Department of Health. [Minn. R. 4725]

5.46.5 Each monitoring well shall be clearly numbered on the outside of the well with either indelible paint or an inscribed number. [Minn. R. 7001]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 18 of 70 Permit modified: 5.46.6 The monitoring wells shall be sampled in accordance with "Minnesota Pollution Control Agency,

Water Quality Division: Sampling Procedures for Ground Water Monitoring Wells, July 1997, Reviewed and re-approved September 2006" or any updates to this document. A copy of this publication is available on the MPCA website at: http://www.pca.state.mn.us. [Minn. R. 7001]

5.46.7 Grab samples shall be collected at all ground water monitoring points (lysimeters or wells) after stabilization tests are conducted. [Minn. R. 7001]

5.46.8 Prior to well purging and sampling, depths to groundwater shall be measured to the nearest 0.01 foot below the top of the well casing, and groundwater elevations shall be reported to the nearest 0.01 foot above mean sea level. [Minn. R. 7001]

5.46.9 Temperature, specific conductance and pH shall be reported as the final field measurements from well stabilization. If the analytical results for pH, temperature, total chloride, or total nitrite plus nitrate (as N) are above applicable drinking water standards, further testing will be required. [Minn. R. 7001]

Surface Discharge Station General Requirements 5.47.10 Analysis Requirements. [Minn. R. 7001] 5.47.11 If monitoring is required for Dissolved Oxygen, pH, Specific Conductance, Temperature and Total


5.47.12 Representative Samples. [Minn. R. 7001] 5.47.13 Samples and measurements required by this permit shall be representative of the monitored

activity. [Minn. R. 7001] 5.47.14 Surface Discharge Prohibitions. [Minn. R. 7001] 5.47.15 Floating solids or visible foam shall not be discharged in other than trace amounts. [Minn. R. 7001] 5.47.16 Oil or other substances shall not be discharged in amounts that create a visible color film. [Minn. R.

7001] 5.47.17 The Permittee shall install and maintain outlet protection measures at the discharge stations to

prevent erosion. [Minn. R. 7001] 5.47.18 Winter Sampling Conditions. [Minn. R. 7001] 5.47.19 The Permittee shall sample flows at the designated monitoring stations including when this requires

removing ice to sample the water. If the station is completely frozen throughout a designated sampling month, the Permittee shall check the "No Discharge" box on the Discharge Monitoring Report (DMR) and note the ice conditions in Comments on the DMR. [Minn. R. 7001]

5.47.20 Phosphorus Limits and Monitoring Requirements. [Minn. R. 7001] 5.47.21 Phosphorus Calculation Definitions. [Minn. R. 7001] 5.47.22 "12-Month Moving Average" is a rolling average. To calculate, add all of the monthly average values

during the last 12 months and divide by 12. [Minn. R. 7001] 5.47.23 "12-Month Moving Total" is a rolling total. To calculate, for each month multiply the total volume of

effluent flow (MG) by the monthly average concentration and by a 3.785 conversion factor to get kg/month. Then add all of the monthly values (kg/mo) during the last twelve months, starting with the monthly total for the month of the current reporting period. [Minn. R. 7001]

5.47.24 Mercury Limits and Monitoring Requirements. [Minn. R. 7001] 5.47.25 Permittees are required to sample for TSS (grab sample) at the same time that Total/Dissolved

Mercury samples are taken. Total Mercury, Dissolved Mercury, and TSS (grab sample) samples shall be collected via grab samples. All results shall be recorded on DMRs. [Minn. R. 7001]

5.47.26 Total and Dissolved Mercury samples shall be analyzed using the most current versions of EPA Method 1631 with clean techniques method 1669. Should another mercury analytical method that has a reportable quantitation level of

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 19 of 70 Permit modified: 5.47.28 "Total Nitrogen" is to be reported as the summation of the Total Kjeldahl Nitrogen and Total Nitrite

plus Nitrate Nitrogen values. [Minn. R. 7001] Waste Stream Station General Requirements 5.48.29 Analysis Requirements. [Minn. R. 7001] 5.48.30 If monitoring is required for Dissolved Oxygen, pH, Specific Conductance, Temperature and Total


5.48.31 Representative Samples. [Minn. R. 7001] 5.48.32 Grab and composite samples shall be collected at a point representative of total influent flow to the

system. [Minn. R. 7001] 5.48.33 Mercury Limits and Monitoring Requirements. [Minn. R. 7001] 5.48.34 Total Mercury samples shall be grab samples and shall be analyzed using EPA Method 1631 with

clean techniques method 1669 and any revisions to those methods. Should another mercury analytical method that has a reportable quantitation level that allows for low-level sample characterization be approved by the EPA and certified by the Minnesota Department of Health, the Permittee is authorized to use that method. [Minn. R. 7001]

5.48.35 Nitrogen Limits and Monitoring Requirements. [Minn. R. 7001] 5.48.36 "Total Nitrogen" is to be reported as the summation of the Total Kjeldahl Nitrogen and Total Nitrite

plus Nitrate Nitrogen values. [Minn. R. 7001] Compliance Construction Schedule 5.49.37 Definitions. [Minn. R. 7001] 5.49.38 "Initiation of operation" means the date that MPCA determines all components of the wastewater

treatment system are complete and functioning and the project begins operating for the purposes for which it was planned, designed, and built. [State Definitions]

5.49.39 "Completion of construction" means all the construction is complete except for minor weather-related components and conforms to the approved plans and specifications and change orders. [State Definitions]

5.49.40 "Notice to proceed" means a written notice given by the Permittee to the contractor that affixes the contract effective date and the date that the contractor begins performing the work specified in the contract documents. [State Definitions]

5.49.41 Schedule. [Minn. R. 7001] 5.49.42 Total Phosphorus Water Quality Based Effluent Limit

Currently, the Permittee discharges its treated wastewater to St. Claire Lake in the winter. St. Claire Lake was placed on the Federal 303(d) list of impaired waters in 2006 for eutrophication due to excess phosphorus. Because the Permittee's discharge has reasonable potential to cause or contribute to the impairment of St. Claire Lake, a water quality based effluent limit (WQBEL) is required. The MPCA has required a 198 kilogram per year (kg/yr) limit for the Facility's discharge. The current Facility is not designed to meet this level of treatment at the design average wet weather flow. Significant capital improvements will be necessary to achieve compliance with the required limit. A compliance schedule was placed in the 2014 reissued permit to accommodate the time required to secure funding, evaluate discharge alternatives, design, and build for advanced nutrient removal technology. This permit modification incorporates the selected discharge alternative and the construction of the upgraded Facility. The Permittee has chosen to upgrade their existing treatment Facility and will include two rotary mechanical screens with six millimeter openings, a new vortex grit chamber, two rotary mechanical fine screens with two millimeter openings, two equalization tanks, an activated sludge system with no clarifier (the activated sludge system will have anaerobic, anoxic and oxic zones), a four-train membrane bio-reactor (MBR) system that specializes in the advanced removal of nutrients, and ultraviolet (UV) disinfection as backup disinfection process. The existing two anaerobic digesters will


be converted to aerobic digesters with sludge pre-thickening. The project also includes dewatering by centrifuge and cake storage of biosolids. The proposed Facility upgrade will result in an Average Wet Weather (AWW) design flow increase to 2.21 mgd. The upgraded Facility will utilize their currently permitted surface discharge location (SD002) as the location for the total Facility effluent. Upon initiation of operation, the Facility will abandon the currently permitted spray irrigation fields, rapid infiltration basins, and will decommission both of the existing polishing ponds. The Permittee must attain compliance with the 198 kg/yr total phosphorus limit as soon as possible, but no later than October 1, 2022. [Minn. R. 7001]

5.49.43 By October 31, 2017, the Permittee shall complete the following processes as needed to address the upgrade for the WWTF; obtain appropriate and necessary right-of-ways, acquire land as appropriate and necessary, and obtain any and all required local permits and approvals as necessary. By this same date, the Permittee shall submit a report describing the results of each of these processes to the MPCA. The Permittee shall submit a report: Due before 10/31/2017. [Minn. R. 7001]

5.49.44 The Permittee shall submit applicable funding application (reapplication) documents to the Minnesota Public Facility Authority by March 3, 2018 for fiscal year 2018 funding. The Permittee shall submit a notification of completion to the MPCA by this same date. The Permittee shall submit a notification: Due before 03/03/2018. [Minn. R. 7001]

5.49.45 The Permittee shall complete the bid advertisement, receive bids, and award a construction contract no later than May 1, 2018. Notify the MPCA in writing of the name and contact information of the company that will perform the construction work. The Permittee shall notify MPCA: Due before 05/01/2018. [Minn. R. 7001]

5.49.46 By June 30, 2018, the Permittee shall submit a report to the MPCA describing all influent total phosphorus reduction actions taken and describe any changes in the influent sampling results from permit issuance until the present time. Included in this report shall be an analysis of how these actions and this data was used in determining the appropriate design of the upgraded treatment facility. The Permittee shall submit a report: Due before 06/30/2018. [Minn. R. 7001]

5.49.47 The Permittee shall begin construction of the upgraded facility no later than December 1, 2018. Notify the MPCA in writing within 14 days that construction started. The Permittee shall begin construction: Due before 12/01/2018. [Minn. R. 7001]

5.49.48 The Permittee shall submit a construction progress report to the MPCA by December 1, 2019. The Permittee shall submit a progress report : Due before 12/01/2019. [Minn. R. 7001]



5.49.51 The Permittee shall submit a Pond Decommissioning Plan, for MPCA review by April 1, 2022. The pond decommissioning plan shall include a detailed description of the proposed work necessary to decommission the pond and include a proposed schedule for completion of each step. The plan shall include but not be limited to: a. A proposal to determine the volume, quality, and method of final disposal of all wastewater liquids; b. A description of the method of final disposal of all biosolids; i. A plan for final sampling and anlaysis of biosolids; ii. A plan for determining the final quantity of biosolids to be disposed. iii. If biosolids will be land applied, the plan shall include. 1. a schedule to employ a Type IV Operator to manage the land application activities; 2. a determination of how much land will be needed based on nitrogen application rates; 3. a description of how pathogen and vector attraction reduction requirements will be met; 4. land application site approval applications shall be submitted as part of the plans and specifications; c. A description of the final disposal of all facility structures including buildings, tanks, ponds, pipes,


equipment, etc. d. Description of the final use of the existing site and any retained structures; e. A schedule for completion of all clean out activities. f. A detailed description of the work required to be completed for decommissioning or relining a wastewater pond facility can be found on the MPCA web site at: http://www.pca.state.mn.us/index.php/view-document.html?gid=14958 i. Preliminary Assessment and Characterization 1. Estimate of the volume of biosolids on both a liquid and dry tons basis. 2. Sampling plan to determine the chemical characteristics. ii. Methods to be used to collect samples to estimate the quantity of biosolids on both a liquid and dry tons basis. iii. Biosolids characterization sampling plan. Biosolids sampling shall be conducted to establish the general quality of the material. A minimum of one sample per six acres of pond area shall be taken. For ponds less than six acres, at least two composite samples shall be taken. iv. Each composite sample shall be composed of a minimum of ten sub-samples. v. The sub-samples shall be taken from the biosolids layer only. vi. Composite samples shall be analyzed for total solids, volatile solids, Kjeldahl nitrogen, ammonia nitrogen, arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, zinc, and PCB's. Samples from secondary ponds, or ponds built after 1984 do not require PCB analysis. vii. A description of how the ponds will be dewatered; viii. A description of how the biosolids will be removed from the pond. The Permittee shall submit a plan: Due before 04/01/2022. [Minn. R. 7001]

5.49.52 The Permittee shall complete construction by May 1, 2022. Notify the MPCA in writing within 14 days of the completion of construction. The Permittee shall complete construction : Due before 05/01/2022. [Minn. R. 7001]

5.49.53 The Permittee shall initiate operation of the upgraded facility by July 1, 2022. Notify the MPCA in writing within 14 days of initiation of operation that the upgraded facility is on-line. The Permittee shall initiate operation : Due before 07/01/2022. [Minn. R. 7001]

5.49.54 The Permittee shall attain compliance with final limits by October 1, 2022. The Permittee shall attain compliance with final limits : Due before 10/01/2022. [Minn. R. 7001]

5.49.55 The Permittee shall abandon and seal all groundwater monitoring wells pursuant to MN Rule ch. 4725 within one (1) year after initiation of operation of the upgraded Facility and after the irrigation sites, RIB cells, and polishing pond have been abandoned. The Permittee shall abandon monitoring well and submit seal record to MPCA : Due 365 calendar days after 10/01/2022. [Minn. R. 7001]

5.49.56 The Permittee shall submit final technical documents to the MPCA within one year after the initiation of operation date. The Permittee shall submit final technical documents : Due by one year after the initiation of operation date. [Minn. R. 7001]

Compliance Schedule Requirements 5.50.57 Chloride Identification/Reduction Plan. [Minn. R. 7001] 5.50.58 Currently the Detroit Lakes Wastewater Treatment Facility has reasonable potential to exceed water

quality standards (WQS) for total chloride. A recent review of data indicates that effluent and influent total chloride concentrations are both consistently above the 230 milligrams per liter (mg/L) WQS. While the proposed upgraded Facility is expecting to have an immediate reduction in total chloride concentrations upon initiation of operation, the new Facility will not be capable of treating total chloride. Due to this, the proposed upgraded wastewater treatment facility will continue to have reasonable potential and will require an effluent limit protective of the 230 mg/L WQS. The effluent limit for the Facility will be 1619 kilograms per day (kg/day) and 230 mg/l as a calendar month average and 267 mg/L as a daily maximum. The Permittee shall meet the final total chloride limits for surface discharge station SD002 as soon as possible but no later than June 30, 2033. A compliance schedule has been included in the permit addressing the Permittee's unique water and


wastewater circumstances. Chloride monitoring to date has shown chloride concentrations in the plant influent have trended down since monitoring started in 2007; the compliance schedule requires the Permittee to monitor the trend prior to and after initiation of operation of the upgraded Facility. The Permittee is in the process of implementing significant improvements at the Facility. Recognizing that the improvements will have some effect on the chloride concentrations in the plant effluent (due to changes in chemical feed and treatment processes), full investigation of chloride treatment alternatives cannot be addressed until the effluent from the upgraded Facility is characterized with respect to chlorides. The compliance schedule outlines an implementation program requiring the Permittee to characterize the influent chloride sources and develop public education strategies prior to a thorough Chloride Monitoring Program based upon the effluent to the upgraded Facility. Additionally, the Permittee has stated it is not financially capable of making a significant capital improvement addressing chlorides as the existing debt service on the water plant carries into 2030 and the new wastewater plant debt service will extend into 2037. [Minn. R. 7001]

5.50.59 By August 15, 2018, the Permittee shall submit a summary (review) of influent monitoring, identifying concentrations and flows from significant users, the Facility influent, and raw wastewater characteristics. The Permittee shall submit review : Due before 08/15/2018. [Minn. R. 7001]

5.50.60 By August 15, 2019, the Permittee shall complete a desktop influent chloride mass balance and submit a summary report identifying sources of chlorides and potential source reduction activities. The mass balance shall be based on monitoring for one year. The Permittee shall submit report : Due before 08/15/2019. [Minn. R. 7001]

5.50.61 By August 15, 2020, the Permittee shall submit a public education strategy plan identifying education campaigns over the next three years that will help make the public aware of the chloride issue and identify opportunities for community members to help the Permittee reduce chlorides. The public education strategy plan shall contain a list of campaign efforts and timelines. The Permittee shall submit a plan : Due before 08/15/2020. [Minn. R. 7001]

5.50.62 By August 15, 2020, the Permittee shall incorporate chloride user agreements for any industry or other user based on influent monitoring. [Minn. R. 7001]

5.50.63 By August 15, 2021, the Permittee shall identify inflow and infiltration (I/I) projects that may help to reduce the seasonal loading of chlorides. [Minn. R. 7001]

5.50.64 By August 15, 2022, the Permittee shall provide the MPCA a summary report of collaboration between the City of Detroit Lakes Water and Wastewater Departments that will identify the future goal of chloride reduction and steps for planning for the future goal accordingly. The Permittee shall submit a report : Due before 08/15/2022. [Minn. R. 7001]

5.50.65 By December 31, 2022, the Permittee shall complete a Softener Audit and submit a summary report to the MPCA. The audit will coincide with the system-wide replacement of water meters scheduled for completion in 2022, where meter installers will note softener type. The Permittee shall provide softener management guidelines to homeowners. This will help the Permittee understand the number of softeners and those that are newer/auto-regenerate. The Permittee shall submit a report : Due before 12/31/2022. [Minn. R. 7001]

5.50.66 By August 15, 2023, the Permittee shall submit a Chloride Monitoring Report summarizing influent and effluent monitoring. Updated influent monitoring will quantify the impact of any source reductions resulting from the previous steps of this compliance schedule, such as industrial user reductions and public education. Effluent monitoring will provide the first data set with the new Facility online to quantify the impact the upgraded treatment Facility has on chloride concentrations. The results of this phase of monitoring will provide the basis of design for strategies addressing chloride concentrations. The Permittee shall update the chloride mass balance as necessary. The Permittee shall submit a report : Due before 08/15/2023. [Minn. R. 7001]

5.50.67 By August 15, 2024, the Permittee shall establish a Citizen's Advisory Committee comprised of SIUs, lake associations, and larger commercial users to lead efforts for the remainder of the compliance schedule. [Minn. R. 7001]

5.50.68 By August 15, 2025, the Permittee shall evaluate the potential need for a water softener replacement program including identifying approaches to enact water softener replacement requirements. The Permittee shall submit a summary report to the MPCA. The Permittee shall submit a report : Due before 08/15/2025. [Minn. R. 7001]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 23 of 70 Permit modified: 5.50.69 By August 15, 2026, the Permittee shall submit a recycled water assessment report to the MPCA.

The recycled water assessment will evaluate potential recycled water uses to aid in the reduction of the chloride load. The Permittee shall submit report : Due before 08/15/2026. [Minn. R. 7001]

5.50.70 By August 15, 2027, the Permittee shall submit to the MPCA a high-level cost estimate (review) for a water softening facility to understand the impact to users. The Permittee shall submit review : Due before 08/15/2027. [Minn. R. 7001]

5.50.71 By August 15, 2028, the Permittee shall submit to the MPCA a Chloride Reduction and Compliance Plan summarizing the reductions made to date, the findings of the water softener replacement program, the recycled water assessment, and the water softening facility. The Chloride Reduction and Compliance Plan shall also include a timeline that leads to final compliance with the water quality based effluent limits by June 30, 2033. The Permittee shall submit a plan : Due before 08/15/2028. [Minn. R. 7001]

5.50.72 Chloride Progress Reports The Permittee shall submit to the MPCA a progress report following the submission of the Chloride Reduction and Compliance Plan identifying progress with implementing the recommendations from the plan. The first progress report shall be submitted by December 31, 2028, and on an annual basis thereafter. The annual progress reports shall include, but are not limited to: a. A summary of all the activities that the Permittee completed during the 12 month period; and b. A schedule of activities the Permittee will complete within the next 12 month period. The Permittee shall submit a progress report : Due before 12/31/2028 annually thereafter. [Minn. R. 7001]

Mercury Minimization Plan 5.51.73 The Permittee is required to complete and submit a Mercury Pollutant Minimization Plan (MMP) to

the MPCA as detailed in this section. If the Permittee has previously submitted a MMP, it shall update its MMP and submit the updated MMP to the MPCA. The purpose of the MMP is to evaluate collection and treatment systems to determine possible sources of mercury as well as potential mercury reduction options. Guidelines for developing a MMP are detailed in this section. [Minn. R. 7001]

5.51.74 The specific mercury monitoring requirements are detailed in the limits and monitoring section of this permit. Information gained through the MMP process can be used to reduce mercury concentrations. As part of its mercury control strategy, the Permittee should consider selecting activities based on the potential of those activities to reduce mercury loadings to the wastewater treatment facility. [Minn. R. 7001]

5.51.75 The Permittee shall submit a Mercury Minimization Plan by 180 days after permit issuance. [Minn. R. 7001]

5.51.76 At a minimum, the MMP shall include the following: a. A summary of mercury influent and effluent concentrations and biosolids monitoring data using the most recent five years of monitoring data, if available. b. Identification of existing and potential sources of mercury concentrations and/or loading to the facility. As appropriate for your facility, you should consider residential, institutional, municipal, and commercial sources (such as dental clinics, hospitals, medical clinics, nursing homes, schools, laundries, and industries with potential for mercury contributions). You should also consider other influent mercury sources, such as stormwater inputs, ground water (inflow & infiltration) inputs, lift station components, and waste streams or sewer tributaries to the wastewater treatment facility. c. An evaluation of past and present WWTF operations to determine those operating procedures that maximize mercury removal. d. A summary of any mercury reduction activities implemented during the last five years.


e. A plan to implement mercury management and reduction measures during the next five years. [Minn. R. 7001]

Spray Irrigation 5.52.77 Authorization. [Minn. R. 7001] 5.52.78 This chapter authorizes the Permittee to apply treated wastewater, as described in the 'Facility

Description' section of this permit, to land application sites using a spray irrigation system. This activity is limited by the 'Limits and Monitoring' section of this permit, as well as the other terms and conditions of this permit. [Minn. R. 7001.0150, 3(E)]

5.52.79 Wastewater Land Application System Management. [Minn. R. 7001] 5.52.80 The wastewater flow to a land application site shall not have physical or chemical characteristics

that prevent the proper operation of the land disposal system. The wastewater shall be free of material that interferes with the operation of nozzles, orifices or flow measurement devices. [Minn. R. 7001.0150, 3(F)]

5.52.81 Wastewater shall be applied so as not to harm vegetation and so that prolonged saturated soil conditions do not develop due to the application. Wastewater shall not be applied during precipitation periods. [Minn. R. 7001.0150, 3(F)]

5.52.82 A cover crop shall be maintained on the sprayfield during the entire application season unless otherwise approved by the MPCA. [Minn. R. 7001.0150, 3(F)]

5.52.83 Wastewater shall not be applied after the cover crop has become dormant as a result of frost or below freezing temperatures. [Minn. R. 7001.0150, 3(F)]

5.52.84 The Permittee shall prevent the surface runoff of wastewater, and precipitation runoff mixed with wastewater, from the land application site(s). The Permittee shall provide runoff collection and re-application systems as appropriate to prevent the discharge of surface runoff. [Minn. R. 7001.0150, 3(F)]

5.52.85 If odor or aerosol drift resulting from operation of the wastewater disposal system creates a nuisance condition, the Permittee shall immediately take appropriate action to control or abate the odor or aerosol drift. The Permittee shall notify the MPCA of a nuisance condition within five (5) days of discovery. [Minn. R. 7001.0150, 3(F)]

5.52.86 Tile inlets shall be capped during spray irrigation events. [Minn. R. 7001.0150, 3(F)] 5.52.87 Best management practices shall be utilized for all crops. The Permittee shall utilize the facility's

Operation and Maintenance Manual, the Sprayfield Management Plan, and the most recent recommendations of the Minnesota Extension Service, University of Minnesota, for managing nitrogen for crop production on irrigated soils. Soil test results shall also be utilized for fertilizer recommendations. [Minn. R. 7001.0150, 3(F)]

5.52.88 If any changes are made to the facilities permitted spray irrigation site the Permittee is required to notify the MPCA and update the facilities sprayfield management plan. This plan shall be kept on-site and made available upon MPCA request. [Minn. R. 7001.0150, 3(F)]

5.52.89 Spray Irrigation Outside of Acceptable Land Application Periods. [Minn. R. 7001] 5.52.90 If conditions require spray irrigation outside of the effective period designated in the limits and

monitoring section of this permit or if an emergency condition exists, the Permittee shall submit to the MPCA the "Spray Irrigation/Rapid Infiltration Basin Discharge Not Authorized Within Permit" form found on the MPCA's website at: http://www.pca.state.mn.us/index.php/water/water-types-and-programs/wastewater/index.html. The form shall be submitted to the MPCA at least two weeks prior to needing to spray irrigate. [Minn. R. 7001.0150, 3(F)]

5.52.91 Reporting. [Minn. R. 7001] 5.52.92 The Permittee shall submit a land application of wastewater annual report : Due by January 21 of

each year following permit issuance. [Minn. R. 7001.0150, 3(F)] 5.52.93 The Land Application of Wastewater Annual Report shall include the following information:

a. A description of the treatment system, including any changes made during the year. b. A description of system operation during the past year, including the following: i. nutrient and hydraulic loading;


ii. irrigation scheduling and intensity; iii. crop harvesting; and iv. problems encountered and any remedial actions. c. A description of system maintenance during the past year, including the following: i. crop types and yields; and ii. irrigation equipment. d. A summarization of monitoring results obtained during the past year from the soil monitoring requirements. e. An analysis of the information submitted, and recommendations for changes, including the following: i. analysis of the year's operation; and ii. proposed changes for the coming year's operation. [Minn. R. 7001.0150, 3(F)]

Spray Irrigation: Soils 5.53.94 Sampling Location. [Minn. R. 7001] 5.53.95 Samples for Station LA319 shall be collected from irrigation sites #1 and #2.

Samples for Station LA320 shall be collected from irrigation sites #3 and #4. Monitoring as these land application sites is required from the effective date of this modification through the time of initiation of operation of the upgraded facility and abandonment of the spray irrigation sites. [Minn. R. 7001]

5.53.96 Soil Samples. [Minn. R. 7001] 5.53.97 Soil samples shall be taken in the spring before the first irrigation and before the first application of

commercial or other supplemental fertilizer for that year. [Minn. R. 7001.0150, 2(B)] 5.53.98 Soil samples shall be a composite of a mixture of 15 to 20 equally proportioned subsamples taken

from a 0- to 8-inch core. At least one composite sample shall be collected for each 40 acres on the permitted land application site. [Minn. R. 7001.0150, 2(B)]

5.53.99 Application Rates. [Minn. R. 7001] 5.53.100 Nitrogen and sodium land application rate limits apply to the sum of all sources of nitrogen or

sodium applied to a permitted application site. [Minn. R. 7001.0150, 3(F)] 5.53.101 If nitrogen or sodium are applied to a permitted land application site from other sources including

commercial fertilizer, manure, silage, sewage or wastewater treatment solids and sludges, then these other nitrogen or sodium sources shall be included in the sum of nitrogen or sodium applied to determine compliance with application rate limits at that site. [Minn. R. 7001.0150, 3(F)]

5.53.102 The nitrogen application rate shall be calculated as the sum of the total annual mass Kjeldahl nitrogen and nitrate-plus-nitrite nitrogen applied to the site, divided by the acreage of the site. [Minn. R. 7001.0150, 3(F)]

Pond System 5.54.103 Ponds - Observations. [Minn. R. 7001] 5.54.104 The Permittee shall inspect the pond system weekly, and shall take measurements of pond water

depth, estimate the coverage of aquatic plants, floating mats and ice cover on the surface of the ponds, and note odors, the condition of the dikes and the presence of muskrats. The Permittee shall maintain records of these weekly inspections for the last three (3) years, and submit the results on the Discharge Monitoring Report (DMR) supplemental form. [Minn. R. 7001.0150, 3(F)]

5.54.105 The Permittee shall maintain daily precipitation records. [Minn. R. 7001.0150, 3(F)] Mechanical System 5.55.106 Bypass Structures. [Minn. R. 7001] 5.55.107 All structures capable of bypassing the treatment system shall be manually controlled and kept

locked at all times. [Minn. R. 7001.0030] 5.55.108 Sanitary Sewer Extension Permit. [Minn. R. 7001]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 26 of 70 Permit modified: 5.55.109 The Permittee may be required to obtain a Sanitary Sewer Extension Permit from the MPCA for any

addition, extension or replacement to the sanitary sewer. If a sewer extension permit is required, construction may not begin until plans and specifications have been submitted and a written permit is granted except as allowed in Minn. Stat. 115.07, Subd. 3(b). [Minn. R. 7001.0020, D]

5.55.110 Operator Certification. [Minn. R. 7001] 5.55.111 The Permittee shall provide a Class A state certified operator who is in direct responsible charge of

the operation, maintenance and testing functions required to ensure compliance with the terms and conditions of this permit. [Minn. R. 9400]

5.55.112 The Permittee shall provide the appropriate number of operators with a Type IV certification to be responsible for the land application of biosolids or semisolids from commercial or industrial operations. [Minn. R. 7001]

5.55.113 If the Permittee chooses to meet operator certification requirements through a contractual agreement, the Permittee shall provide a copy of the contract to the MPCA, WQ Submittals Center. The contract shall include the certified operator's name, certificate number, company name if appropriate, the period covered by the contract and provisions for renewal; the duties and responsibilities of the certified operator; the duties and responsibilities of the permittee; and provisions for notifying the MPCA 30 days in advance of termination if the contract is terminated prior to the expiration date. [Minn. R. 9400]

5.55.114 The Permittee shall notify the MPCA within 30 days of a change in operator certification or contract status. [Minn. R. 9400]

Rapid Infiltration Basin (RIB) 5.56.115 The Permittee shall not operate the rapid infiltration basins in months outside of those indicated in

the Limits and Monitoring section of this permit. Where favorable weather and operational conditions exist, the Permittee may request permission from the MPCA to use the basins outside of the dates in this permit. [Minn. R. 7001.0150, 3(F)]

5.56.116 If conditions require rapid infiltration basin use outside of the effective period designated in the limits and monitoring section of this permit or if an emergency condition exists, the Permittee shall submit to the MPCA the "Spray Irrigation/Rapid Infiltration Basin Discharge Not Authorized Within Permit" form found on the MPCA's website at: http://www.pca.state.mn.us/index.php/water/water-types-and-programs/wastewater/index.html. The form shall be submitted to the MPCA at least two weeks prior to needing to use the rapid infiltration basin. [Minn. R. 7001.0150, 3(F)]

5.56.117 The Permittee shall follow the approved operation and maintenance manual for dosing and resting the rapid infiltration basins in order to maximize effluent treatment. Use of the rapid infiltration basins shall cycle in a dosing/resting operational mode. [Minn. R. 7001.0150, 3(F)]

5.56.118 The entire basin cross-sectional area shall be uniformly loaded. [Minn. R. 7001.0150, 3(F)] Pretreatment: Undelegated Requirements 5.57.119 Pretreatment - Definitions. [Minn. R. 7049] 5.57.120 An "Individual Control Mechanism" is a document, such as an agreement or permit, that imposes

limitations or requirements on an individual industrial user of the POTW. [Minn. R. 7049] 5.57.121 "Significant Industrial User" (SIU) means any industrial user that:

a. discharges 25,000 gallons per day or more of process wastewater; b. contributes a load of five (5) % or more of the capacity of the POTW; or c. is designated as significant by the Permittee or the MPCA on the basis that the SIU has a reasonable potential to adversely impact the POTW, or the quality of its effluent or residuals. [Minn. R. 7049]

5.57.122 Pretreatment - Permittee Responsibility to Control Users. [Minn. R. 7049] 5.57.123 It is the Permittee's responsibility to regulate the discharge from users of its wastewater treatment

facility. The Permittee shall prevent any pass through of pollutants or any inhibition or disruption of the Permittee's facility, its treatment processes, or its sludge processes or disposal that contribute to


the violation of the conditions of this permit or any federal or state law or regulation limiting the release of pollutants from the POTW. [Minn. R. 7049]

5.57.124 The Permittee shall prohibit the discharge of the following to its wastewater treatment facility: a. pollutants which create a fire or explosion hazard, including any discharge with a flash point less than 60 degrees C (140 degrees F); b. pollutants which would cause corrosive structural damage to the POTW, including any waste stream with a pH of less than 5.0; c. solid or viscous pollutants which would obstruct flow; d. heat that would inhibit biological activity, including any discharge that would cause the temperature of the waste stream at the POTW treatment plant headwork's to exceed 40 degrees C (104 degrees F); e. pollutants which produce toxic gases, vapors, or fumes that may endanger the health or safety of workers; or f. any pollutant, including oxygen demanding pollutants such as biochemical oxygen demand, released at a flow rate or pollutant concentration that will cause interference or pass through. [Minn. R. 7049]

5.57.125 The Permittee shall prohibit new discharges of non-contact cooling waters unless there is no cost effective alternative. Existing discharges of non-contact cooling water to the Permittee's wastewater treatment facility shall be eliminated, where elimination is cost-effective, or where an infiltration/inflow analysis and sewer system evaluation survey indicates the need for such removal. [Minn. R. 7049]

5.57.126 If the Permittee accepts trucked-in wastes, the Permittee shall evaluate the trucked in wastes prior to acceptance in the same manner as it monitors sewered wastes. The Permittee shall accept trucked-in wastes only at specifically designated points. [Minn. R. 7049]

5.57.127 Pollutant of concern means a pollutant that is or may be discharged by an industrial user that is, or reasonably should be of concern on the basis that it may cause the permittee to violate any permit limits on the release of pollutants. The following pollutants shall be evaluated to determine if they should be pollutants of concern: pollutants limited in this permit, pollutants for which monitoring is required in this permit, pollutants that are likely to cause inhibition of the Permittee's POTW, pollutants which may interfere with sludge disposal, and pollutants for which the Permittee's treatment facility has limited capacity. [Minn. R. 7049]

5.57.128 Control of Significant Industrial Users. [Minn. R. 7049] 5.57.129 The Permittee shall impose pretreatment requirements on SIUs which will ensure compliance with

all applicable effluent limitations and other requirements set forth in this permit or any federal or state law or regulation limiting the release of pollutants from the POTW. These requirements shall be applied to SIUs by means of an individual control mechanism. [Minn. R. 7049]

5.57.130 The Permittee shall not knowingly enter into an individual control mechanism with any user that would allow the user to contribute an amount or strength of wastewater that would cause violation of any limitation or requirement in the permit, or any applicable federal, state or local law or regulation. [Minn. R. 7049]

5.57.131 Monitoring of Significant Industrial Users. [Minn. R. 7049] 5.57.132 The Permittee shall obtain from SIUs specific information on the quality and quantity of the SIU's

discharges to the Permittee's POTW. Except where specifically requested by the Permittee and approved by the MPCA, this information shall be obtained by means of representative monitoring conducted by the Permittee or by the SIU under requirements imposed by the Permittee in the SIU's individual control mechanism. Monitoring performed to comply with this requirement shall include all pollutants for which the SIU is significant and shall be done at a frequency commensurate with the significance of the SIU. [Minn. R. 7049]

5.57.133 Reporting and Notification. [Minn. R. 7049] 5.57.134 The Permittee shall submit a pretreatment annual report : Due by 31 days after the end of each

calendar year following permit issuance if a SIU discharges to the POTW during a given calendar year. [Minn. R. 7049]

Permit issued: February 06, 2014 MN0020192 Permit expires: January 31, 2019 Page 28 of 70 Permit modified: 5.57.135 The Pretreatment Annual Report shall be submitted on forms provided by the agency or shall

provide equivalent information. The Permittee shall submit the pre-treatment report to the following address: MPCA Attn: WQ Submittals Center 520 Lafayette Road North St. Paul, Minnesota 55155-4194. [Minn. R. 7049]

5.57.136 The Permittee shall notify the MPCA in writing of any: a. SIU of the Permittee's POTW which has not been previously disclosed to the MPCA; b. anticipated or actual changes in the volume or quality of discharge by an industrial user that could result in the industrial user becoming an SIU as defined in this chapter; or c. anticipated or actual changes in the volume or quality of discharges by a SIU that would require changes to the SIU's required local limits. This notification shall be submitted within 30 days of identifying the IU as a SIU. Where changes are proposed, they shall be submitted prior to changes being made. [Minn. R. 7049]

5.57.137 Upon notifying the MPCA of a SIU or change in a SIU discharge as required above, the Permittee shall submit the following information on forms provided by the agency or in a comparable format: a. the identity of the SIU and a description of the SIU's operation and process; b. a characterization of the SIU's discharge; c. the required local limits that will be imposed on the SIU; d. a technical justification of the required local limits; and e. a plan for monitoring the SIU which is consistent with monitoring requirements in this chapter. [Minn. R. 7049]

5.57.138 In

Documents

Draft NPDES and SDS Permit to City of Detroit Lakes ......screens with six millimeter openings, a new vortex grit chamber, two rotary mechanical fine screens with two millimeter openings,