Industrial Pretreatment

The Des Moines Metropolitan Wastewater Reclamation Authority (WRA) is the local Control Authority responsible for enforcing regulations in the Federal Clean Water Act and local ordinances by ensuring industrial and commercial dischargers remain compliant with all applicable environmental laws as it pertains to wastewater discharged to the publicly owned treatment works (POTW).  There are over 2,500 commercial and industrial facilities that fall under the WRA’s jurisdiction, and over 60 industrial facilities operate under industrial wastewater discharge permits. Each facility is subject to specific regulations regarding wastewater discharge to the POTW depending on the nature of their business and potential for pollutant discharges to the sanitary sewer. For information regarding industrial pretreatment requirements, please refer to Chapter 118, Article III of the Municipal Code.

New & Current Industrial Users

All new industrial users (IU) or existing industrial users looking to expand or modify operations need to fill out an Industrial User Survey and submit it to the WRA for review prior to construction and not less than 180 days prior to commencing discharge. The WRA may require specific wastewater pretreatment measures, sampling equipment, discharge sampling points, and/or other measures depending on the nature of your business.

Wastewater Discharge Permits

Prior to the WRA issuing a new or renewed permit to an IU, the IU must submit a completed Industrial Wastewater Discharge Permit Application along with the appropriate annual permit fee and one-time permit application fee to the Regulatory Compliance Department at the Des Moines Wastewater Reclamation Facility (WRF).

The annual permit fee for a Class A and Class B Wastewater Discharge Permit is $1,000 and $400, respectively. For initial permittees, a one-time permit application fee of $200 for a Class A permit or $100 for a Class B permit will also be assessed. Information pertaining to fees associated with industrial wastewater discharge permits and related activities is listed in Section 118-352 of the City of Des Moines Municipal Code.

Slug Discharges to POTW

In the event of a slug discharge (as defined in your respective permit), the IU must immediately notify the WRF Treatment Manager and/or Regulatory Compliance Department at 515-323-8010 or 515-323-8133. If calling outside of normal working hours (7 am to 4 pm), please call WRF Operations at 515-323-8040. In a follow-up to such an event, the IU shall fill out a Slug Discharge Form and promptly submit it to the Regulatory Compliance Department.

Authorization to Discharge (non-permitted facilities)

Discharge of any potentially harmful contaminants into the sewer system which may cause damage to the POTW or environment is not allowed without prior notification to and approval from the WRA Director. Examples of such include (but are not limited to):

  • Contaminated groundwater
  • Laboratory chemicals
  • Pesticides
  • Petroleum products
  • Stormwater in containment areas
  • Various industrial wastes
  • Various medical wastes
  • Wastewater from construction activities/sites
  • Other associated chemicals

If you are unsure if the waste is harmful, damaging, or hazardous, please call 515-323-8133 or email Paul Ebert. Prior to discharging any potentially harmful contaminants into the sewer system, please fill out a Discharge Authorization Form and submit it via email or fax to 515-323-8063 and await approval.

Discharge Prohibitions

At no time should hazardous waste or materials be disposed of into the sanitary or storm sewer system. For proper disposal of hazardous waste, please call the Metro Waste Authority Regional Collection Center in Bondurant, Iowa at 515-967-5512.

Even certain non-hazardous wastes may be harmful to the sewer infrastructure, create a dangerous environment in the collection system, or pose a health hazard to Public Works employees and contractors. A complete list of these prohibited discharges can be found in Section 118-342 of the Municipal Code. A summary:

  • The pH of all materials discharged to the POTW shall be between 5.0 to 12.0
  • Pollutants shall not create a fire or explosion hazard
  • Pollutants shall not solidify or become viscous between 32 to 150 degrees Fahrenheit
  • Pollutants shall not cause interference or pass through at the treatment plant
  • Wastewater shall be less than 150 degrees Fahrenheit
  • Pollutants shall not result in the presence of toxic gases, vapors, or fumes
  • Wastewater shall not contain more than 3,000 milligrams per liter of suspended solids or dissolved solids (such as salts, slurries, etc.)
  • Wastewater shall not have excessive coloration (dyes, tanning solutions, etc.)
  • All trucked or hauled wastes shall be brought to the Des Moines Wastewater Reclamation Facility for pre-approved disposal-discharge into private drains or public access points (manholes) is not allowed.

Hazardous Waste Reporting Requirements for Industrial Users

Under RCRA’s Domestic Sewage Exclusion, any mixture of domestic sewage and other wastes that passes through a sewer system to a POTW is not considered a hazardous waste for purposes of RCRA.  For this reason, reporting of these discharges are regulated under and required by the Clean Water Act.  Industrial Users who discharge process water to the Des Moines Metropolitan WRA POTW, whether by piped-connection or hauled waste, are required under 40 CFR 403.12(p)&(j) to report discharge of hazardous waste as follows:

  • 40 CFR 403.12(p) requires a one-time report for each substance discharged to a POTW that, if otherwise disposed of, would be considered a RCRA hazardous waste; a report shall be submitted to the Des Moines WRA, State of Iowa hazardous waste authority, and EPA Regional Waste Management Director
  • 40 CFR 403.12(j) requires a report in advance to these same entities listed above of any substantial change in volume or character of any Industrial User discharge

Who Must Notify?  All Industrial Users who discharge characteristic or listed wastes under 40 CFR 261 in which the total waste discharged is greater than or equal to 15 kg per calendar month of non-acute hazardous waste, or those who discharge any amount of acute hazardous waste. Notification shall be made within 180 days of the discharge of the hazardous waste. For more information, please visit EPA’s website.