Executive Summary:
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) amended its Sewage and Waste Control Ordinance (SWCO), effective February 5, 2026, and revised its User Charge Ordinance (UCO), effective January 1, 2026. These updates affect non-residential facilities throughout Cook County, particularly Industrial Users and Non-Discharging Categorical Industrial Users (NDCIUs). Key changes include the formal classification and annual certification of NDCIUs, updated reporting and user-charge requirements, and revisions intended to streamline administrative processes. The ordinances also reinforce existing compliance obligations related to hazardous material reporting, slug discharge prevention, and toxic organic compound management. Depending on a facility’s operations, applicable requirements may include submitting to MWRDGC a Flammables, Volatiles, Explosives, and Corrosives (FVEC) Form, maintaining a Slug Control Plan, or developing a Toxic Organic Management Plan (TOMP).
User Charge Ordinance
The User Charge Ordinance (UCO) administers a system through the User Charge Program for charging all non-residential users for their use of the MWRDGC’s sewage collection and treatment system.
Who is subject?
The ordinance applies broadly to all non-residential sources, with a facility’s specific fee status determined through the Facility Classification Questionnaire (FCQ). Rather than functioning as a tax, the UCO is structured as a fee. Organizations that are otherwise tax-exempt may still be subject; however, local Government Users are exempt from fees altogether. Small Nonresidential Commercial-Industrial Users (users that discharge waste not exceeding a flow of 25,000 gallons per day, a BOD loading of 25 pounds per day, and a suspended solids loading of 35 pounds per day) are only required to file the FCQ and are not subject to further fee obligations. NDCIUs will now be formally classified and must annually certify that they have not discharged regulated process wastewater to the MWRDGC’s sewer system.
What is included in submittal?
For facilities that are subject to fees, the User Charge Annual Certified Statement (RD-925 form) must be submitted annually on February 20th for the previous calendar year to calculate the charge owed for the year’s usage.
Flammables, Volatiles, Explosives, and Corrosives Form
A Flammables, Volatiles, Explosives, and Corrosives (FVEC) form is utilized to annually report on-site storage of hazardous materials to MWRDGC.
Who is subject?
The form requires facilities to disclose any flammable, volatile, explosive, or corrosive materials kept on-site in quantities greater than 50 gallons.
What is included in submittal?
The form requires supporting details for each material, including the specific material name, the storage method used (such as a tank, drum, or tote), and the maximum quantity kept on site at any given time.
Slug Control Plan
A Slug Control Plan is a facility’s plan for preventing and responding to a “Slug Discharge”. A “Slug Discharge” is defined as any non-routine, episodic discharge (typically a spill, but also atypical batch discharges) that has the potential to pass through a publicly owned treatment works (POTW) or violate discharge limits.
Who is subject?
Under SWCO Article V, Section 4, any industrial user that uses or stores flammable, volatile, explosive, or corrosive materials, or that otherwise has the potential for a slug discharge, is required to maintain a Slug Control Plan. There is no minimum container size that exempts a chemical from being addressed in the Slug Control Plan.
What is included in the plan?
The Slug Control Plan must contain the elements as defined in the General Pretreatment Regulations, 40 CFR 403.8(f)(2)(vi). Detailed requirements can be found in the MWRDGC document “Elements of a Slug Control Program”. Elements of a Slug Control Plan include:
- General source information
- Plant Layout/Flow Diagrams
- Material Inventory
- Spill and Leak Prevention
- Emergency Response Equipment and Procedures
- Spill and Slug Reporting Procedures
- Employee Training Program
- Slug Control Plan Certification
Slug Control Plan functions similarly to a Spill Prevention, Control, and Countermeasure (SPCC) Plan in that MWRDGC requires the plan to be certified by an Illinois-licensed Professional Engineer (PE). However, instead of covering only oils, a Slug Control Plan covers all chemicals stored or used on-site. Facilities that submit site plans and containment details without sufficient specificity should expect to receive a deficiency notice requesting more information. Under MWRDGC’s SWCO, Slug Control Plans are re-evaluated by MWRDGC every two (2) years.
Toxic Organic Management Plan
A Toxic Organic Management Plan (TOMP) is a facility-specific plan required only for industrial users that fall under certain federal categorical pretreatment standards known to use toxic organic compounds in their processes.
Who is subject?
A TOMP is only required for specific categories of industrial sources:
- 40 CFR 413 – Electroplating Point Source Category
- 40 CFR 433 – Metal Finishing Point Source Category
- 40 CFR 464 – Metal Molding and Casting Point Source Category
- 40 CFR 465 – Coil Coating Point Source Category
- 40 CFR 467 – Aluminum Forming Point Source Category
- 40 CFR 468 – Copper Forming Point Source Category
- 40 CFR 469 – Electrical and Electronic Components Point Source Category
For regulated industrial users in the Electroplating, Metal Finishing, and Electrical and Electronic
Components categories, a TOMP can be utilized as an alternative to routine Total Toxic Organics (TTO) monitoring.
What is included in the plan?
A TOMP must include a list of the toxic organic compounds used or generated on-site, the method of disposal for those compounds, and the procedures in place to prevent spills or leaks from entering the facility’s wastewater discharge. Per US EPA’s Guidance Manual for Implementing Total Toxic Organics (TTO) Pretreatment Standards (1985), a TOMP should include the following items at a minimum. Facilities looking for more detailed guidance on preparing a TOMP may refer to Chapter 4 of the Guidance Manual.
- A complete inventory of all toxic organic chemicals in use or identified through sampling and analysis of the wastewater from regulated process operations (organic constituents of trade-name products should be obtained from the appropriate suppliers as necessary);
- Descriptions of the methods of disposal other than dumping used for the inventoried compounds, such as reclamation, contract hauling, or incineration;
- The procedures for ensuring that the regulated toxic organic pollutants do not spill or routinely leak into process wastewaters, floor drains, non-contact cooling water, groundwater, surface waters, or any other location which allows discharge of the compounds; and
- Determinations, or best estimates, of the identities and approximate quantities of toxic organic pollutants used as well as discharged from the regulated manufacturing processes. Compounds present in waste streams that are discharged to sanitary sewers may be a result of regulated processes or disposal, spills, leaks, rinse water carryover, air pollution control, and other sources.
Conclusion
The 2026 SWCO and UCO amendments provide an important opportunity for Cook County facilities to confirm that their MWRDGC classifications, authorizations, and compliance plans remain complete and current. A proactive compliance review can help identify outdated information, missing documentation, and potential deficiencies before they result in an MWRDGC notice. Specifically, Trinity recommends the following actions for Cook County facilities.
- Review the requirements of the SWCO and UCO to verify compliance.
- Conduct a facility walk-through to ensure your facility’s Discharge Authorization Request (DAR) application is still accurate and your facility’s Discharge Authorization (DA) is up to date.
- To ensure your facility is properly classified, facilities should verify that a Facility Classification Questionnaire (FCQ) has been submitted.
- Track deadlines for annual certifications, forms, and reports:
- MWRDGC NDCIU Certification Statement – Due annually on February 15th
- User Charge Annual Certified Statement (RD-925 form) – Due annually on February 20th
- FVEC Form – Due annually
- Nearly all non-residential sources in Cook County require a Slug Control Plan – if your facility does not have one, expect notice from MWRDGC requiring submittal.
For questions, assistance evaluating applicability, updating an authorization, or preparing the required compliance documentation, please contact Audrey Freeman in the Chicago Office.
Sources:
