Guide for Batch Discharge Authorization to the City’s Sewer System

Batch discharge authorizations are issued to businesses or projects that need to discharge to the sanitary sewer or, in rare cases, to the stormwater system. Discharges are limited in volume, duration, and frequency. Learn more about the batch discharge authorization procedure on this page.
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Batch Discharge Authorizations are for discrete, one-time discharges from a known waste stream with a known volume. Example discharges include power washing water, chlorinated water from a commercial or public pool draining, chlorinated water from water line disinfection, or miscellaneous non-domestic wastewater.

For information about other discharge types, visit the Guide to Industrial Wastewater Discharges to the City’s Sewer System.

Discharge Requirements

In most cases, Batch Discharge Authorization is granted for discharges to the sanitary and combined sewer. However, in rare cases, Batch Discharge Authorization may be granted for discharges to the stormwater system.

Sanitary and Combined Sewer Discharge Requirements:

  • The discharge must not take place during a rain event in accordance with City of Portland's National Pollutant Discharge Elimination System Discharge Permit. A rain event is when measurable rainfall occurs in the area of the discharge location. A rain event is over when there has been no rain in the area for 8 consecutive hours. Snow and ice melt are considered wet weather.
  • Best management practices (i.e., filtering, settling, etc.) must be utilized, and systems must be maintained to reduce solids entering the City's sanitary sewer system. Any material other than domestic waste larger than 0.25" in any dimension is prohibited under 17.34.030(B)(7).
  • Discharges shall comply with the prohibitions and limitations established in Portland City Code (PCC) 17.34.030 and Sanitary Discharge and Pretreatment Program Administrative Rules ENB-4.03(3).
    • Installation and maintenance of treatment devices may be required.
  • The batch discharge flow rate is to be equal to or less than 50 gallons per minute (gpm) and less than 25,000 gallons per day (gpd). Batch discharge flow rates greater than 50 gpm require additional authorization by the City Bureau of Environmental Services Maintenance Engineering Section. It may take up to a week for Engineering to respond to the request. You may be required to:
    • Limit the discharge rate,
    • Change the location of discharge,
    • Require discharger's personnel to be available to monitor the discharge and to be in contact with City personnel monitoring the flow.
  • Within 30 days of final discharge, you must submit a completed Batch Discharge Report to The report is used to document the total volume of discharges and will be used for billing purposes.

Stormwater System Discharge Requirements:

  • Non-stormwater discharges to the City storm system are limited to those allowed by the City of Portland's National Pollutant Discharge Elimination System Discharge Permit. All other non-stormwater discharges must be discharged to the sanitary sewer system, with approval from the City.
  • Discharges shall comply with the prohibitions and limitations established in Portland City Code (PCC) 17.39 and City Storm Sewer and Drainage System Administrative Rules ENB-4.13.
  • Discharges must not cause or contribute to a violation of in-stream water quality standards.
  • Discharge rates must be approved by the City. It can take up to a week to verify the allowable flow rate for the discharge. Based on the system capacity analysis, you may be required to:
    • Limit the discharge rate,
    • Change the discharge location,
    • Decrease the discharge rate during wet or extreme wet weather as defined by the City.
  • Control measures must be implemented, as required by the City, to control sediment and any other pollutants of concern as identified by the City in the discharge.
  • Monitoring of the discharge, including visual observations, may be required as determined by the City.
  • The volume discharged must be measured, and within 30 days of final discharge, the discharger must submit a completed Discharge Flow Report to the City. The report is used to document the total volume of discharges and will be used for billing purposes.

Apply for Batch Discharge Authorization

For instructions on how to apply for Batch Discharge Authorization, visit Apply for Batch Discharge Authorization to the City's Sewer or Stormwater System.

Batch discharges are not allowed without written authorization, are subject to administrative fees, and may be subject to current sewer rates.

Fees and Charges

Batch Discharge Authorizations are $195 each. If applicable, the batch discharge volume to the sanitary sewer will be charged the current sewer rate of $13.00 per 100 cubic feet.

Current fees and charges are valid through June 30, 2025.

Frequently Asked Questions and Answers

How do I find my sewer asset number?
Go to and enter the site's address; in the menu that appears, scroll to "Utilities" and click "Sewer Assets." Then, find a discharge location and pick the asset that is the most feasible discharge location for your project. Green lines are stormwater, purple lines are combined sewers, and red are sanitary sewer pipes. See the legend for a full key. The asset ID is the 6-digit alphanumeric code.

Can I receive an exception to discharge during wet weather?
All exemptions require Environmental Services modeling to determine if the discharge piping has feasible capacity during wet weather or annual peak storm events. If modeling results determine that it is feasible, we may be able to authorize an exception on a case-by-case basis. It is rare when an exception is approved so be prepared to only be allowed to discharge during dry weather. Dry weather is defined as a period in which there has been no measurable rainfall in the previous 8 hours and is not currently raining. For historical rainfall measurements, please view the City's HYDRA Rainfall Network and choose the rain gauge closest to your site. Additionally, check hourly weather forecasts to prevent discharge during wet weather that may occur after a discharge event has started.

How can I find site contamination records?
You can search by address Leaking Underground Storage Tank (LUST) database and the Environmental Site Information database.

Do I need a permit to use the maintenance hole in the middle of the street?
Yes, you may need to apply for a Temporary Street Use Permit.

Can I discharge to the stormwater system?
You may request discharge to storm on the Batch Discharge Application. If a request to the storm system is indicated, the application will be forwarded and processed by the Environmental Services' Stormwater Section. If approved, a permit or authorization will be issued directly. If your application is denied, you will be notified, and you will need to reapply and request discharge to the sanitary or combined sewer system.

Can I get a reduced sewer rate?
No, if the discharge is to the storm system, you will be charged the current fiscal year charge per 1 CCF of water volume discharged.

The City's Role

The Clean Water Act requires cities to set rules and regulations to protect the City's sewer and stormwater systems and watersheds. Environmental Services works with businesses and industries to meet these requirements.

Rules and Regulations

  • Portland City Code 17.39 prohibits nearly all discharges to the stormwater system, including any wash water, wastewater, chlorinated water, and discharges that are discolored, turbid, oily, or have a sheen. Learn more about the very limited times when discharge to the stormwater system may be authorized.
  • Portland City Code 17.32 prohibits directing water from any source to run onto any City sidewalk, street, easement, or right-of-way without obtaining authorization or approval.
  • Portland City Code 17.34 and Administrative Rules ENB-4.03 require batch discharge authorization before discharging to the sanitary sewer system.