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MPCA's compliance and enforcement program tracks how well wastewater treatment facilities are complying with their permits and takes enforcement actions when necessary. The agency provides information, tools, and incentives to assist municipalities and businesses in complying with the law.

8551: Wastewater operators recognition
Five white stars and the word Excellence on a blue background

Operational excellence

The MPCA recognized 235 wastewater facilities for outstanding operations in 2024.

Guidance for flooding or wastewater release

Facility signage: Response steps for unauthorized wastewater release

When to report a discharge/release to the MN Duty officer (651-649-5451, 800-422-0798)

  • Minnesota Duty Officer
  • When your permit requires it. Even if MPCA compliance staff are aware of the discharge, call the MN Duty Officer to ensure compliance with your permit.
  • Whenever there is a discharge, accidental or otherwise, of any substance or material that may cause pollution of waters of the state. When in doubt, call.
  • When there is a petroleum discharge over five gallons, though any petroleum discharge that causes a nuisance condition to waters of the state should be reported to the Duty Officer.

Facility operations guidance and manual

Worksheets and spreadsheet for operators

The following worksheets and spreadsheets are designed to help operators do various required calculations, such as the amount of water pond operators need to discharge for winter or summer storage and calculations needed to calibrate lift station pumps. Some of the calculations are required in your NPDES permit. Remember to keep records for at least three years.

Frequently asked questions

Annual reporting

Pretreatment annual report

Priority Pollutant monitoring

Priority Pollutant monitoring is required as part of some National Pollutant Discharge Elimination System (NPDES)/ State Disposal System (SDS) permits. These reports have historically been submitted as PDF lab reports, the MPCA is now requiring that this data also be submitted in an electronic data deliverable (EDD) using EQuIS Lab_MN format. Use the following instructions to obtain the EDD in the LAB_MN format from your laboratory for submittal.

Common violations and ways to avoid them

ViolationExamples of violationPreventative measures
Incomplete, incorrect, or late DMR-related reporting or missed monitoring eventsSubmitted incomplete or incorrect report or DMR, failed to submit required sampling or monitoring results on the correct form, or failed to complete a monitoring event
  • Double-check to ensure reporting of all parameters
  • Explain any missing data on the DMR in comments section or as attachment
  • Use electronic calendar reminders for sampling; add sampling schedules to daily paper calendars and planners
  • Supervisors ensure samples are collected and all parameters are tested
  • Properly train staff
  • Make a plan for staff departures, vacations, and illnesses
Limit exceedanceAny monitoring result over the permit limit (see Limits and Monitoring section of permit)Properly maintain your equipment
Late or missing DMRDMRs not submitted or not submitted on time as required in permit
  • Use calendar reminders
  • Supervisors ensure DMR submittal
  • Properly train staff
  • Make a plan for staff departures, vacations, and illnesses
Records not maintainedRecords of equipment calibration, sampling, training,  inspection or required lab records are missing
  • Train records-maintenance staff on records requirements, such as how long they must be kept and making them available to MPCA
  • Make a plan for staff departures, vacations, and illnesses; ensure backup staff have records training
  • Ensure records are maintained when using a third-party contractor
Unauthorized releaseA wastewater overflow or spill is released to the environment (e.g., sanitary sewer overflow from plugged collection system, pump or electrical failures, or overwhelming rain or snow melt)
  • Provide facility with emergency backup power
  • Regularly inspect and service lift station pumps
  • Maintain collection systems
Inadequate equipment calibration or calibration frequencyFlow, pH, or dissolved oxygen meter is not calibrated to required specificationsProperly train staff on equipment calibration, procedures, and frequency
Proper sample preservation procedures not followedA sample was not tested for pH within 15 minutes of being collected or a sample temperature was not maintained at 4 - 6 degrees CelsiusProperly train staff on sample preservation procedures
Late reports or permit applicationNot submitting reports (e.g., bio-solids, spray irrigation, industrial byproduct) or applying for a permit reissuance in a timely manner
  • Supervisors ensure proper permitting procedures
  • Use calendar reminders
  • Properly train staff
  • Make a plan for staff departures, vacations, and illnesses
  • Contact MPCA permitting staff for assistance
Nuisance conditions

A discharge to surface water causes

  • floating solids
  • a scummy film along with strong, obnoxious odors
  • visible oil film
  • degradation of aquatic habitat
  • excessive suspended solids
  • material discoloration
  • other harmful effects
  • Check that all proper operations and maintenance procedures are being followed
  • Respond quickly to negative changes in the facility's system and its effluent
  • Store chemicals and other materials in areas that won't be affected by an uncontrolled discharge
  • Properly train staff
Failure to notify and avoid water pollution
  • Failure to immediately notify the MPCA of the discharge/release
  • Failure to rapidly respond and recover discharged/released material
  • Failure to stop or minimize pollution of waters of the state
  • Notify the MPCA of any discharge that may pollute waters of the state immediately upon becoming aware of it. The preferred notification method is to call the Minnesota Duty Officer (651-649-5451, 800-422-0798).
  • Quickly begin response activities to stop or minimize and contain discharge
  • Recover discharged material, when possible

Concerns at non-regulated facilities

Resources