S5.C.9 Illicit Connection and Illicit Discharge Detection and Elimination (IDDE)

Summary of Program Component

ES operates a robust Illicit Connection and Discharge Detection and Elimination (IDDE) program through field screening, stormwater monitoring, source control inspections, spills and complaint response, and construction inspections.  This program also addresses prohibited discharges and associated source control BMPs for non-stormwater discharges as outlined in the Permit.

Chapter 12.08D of the TMC provides enforcement authority to prevent illicit connections and illicit discharges to City stormwater system and sanitary sewers.  See Section S5.C.1 of this document for specific code citations. 

IDDE Field Screening Program

The City IDDE Field Screening Program consists of several components:

• Video inspection, of the storm sewer pipes;

• Smoke-testing and/or dye testing of the sanitary and stormwater systems; and

• Base flow sampling.

The city uses video inspection of the stormwater conveyance system.  This program is used to assess pipe condition and to identify illegal connections to the stormwater system.  Suspect connections identified as a part of this program are further investigated by smoke and/or dye testing and removed as appropriate. 

The City also has an ongoing Sanitary Inflow and Infiltration Program.  Under this program, field crews investigate sanitary connections by smoke testing the sanitary sewer.  If properties appear not to be connected to the sanitary system, the stormwater system is then smoke tested to determine if there is an illicit connection from the sanitary side sewer to the stormwater system.  If smoke testing cannot confirm a connection to the sanitary or storm systems, field crews then conduct dye testing to verify connections.  All misdirected connections are required to be remedied.

Both the video inspection and the smoke-testing field screening data are collected and stored on the City’s GIS system.  

The City also conducts base flow sampling at selected outfalls to aid in identifying illicit connections and discharges in the MS4.

The permit requires 12 percent on average of the MS4 to be screened each calendar year.  

The City’s existing IDDE program follows standard procedures based on the guidance document: Illicit Connection and Illicit Discharge Field Screening and Source Tracing Guidance Manual prepared by Herrera Environmental Consultants, (IC-ID Manual).  The City began following the guidelines and procedures of the updated IC-ID manual upon its release on May 7, 2020.

Maintain Publicly Listed Water Quality Complaint Hotline

In 2018, the City began using its own TacomaFIRST 311 as our water quality complaint line for spills and illicit discharges.  TacomaFIRST 311 is used as a platform for anyone within the City to call.  Residents can call 311 within the City or (253) 591-5000 from anywhere else.  TacomaFIRST 311 is included in directories throughout the City, on watershed signs along major arterials, and on 311 and stormwater promotional materials.  TacomaFirst 311 can be accessed via telephone call, electronically on the City’s website at www.cityoftacoma.org/surfacewater, www.cityoftacoma.org/tacomafirst311, and is available as an application for mobile devices. The City began the transition from TacomaFirst 311 to SEECLICKFIX in 2022.  While this transition is underway, TacomaFirst 311 will be the primary platform available to residents. 

Training Program for City wide Staff to Identify and Report Illicit Discharges and Connections

All City staff are provided Illicit Discharge Awareness (IDA) training on how to identify and report illicit discharges.  This training is now part of the City’s onboarding process for all new hires.  In 2021, the City updated its IDA training with a new online LinkedIn Learning video module.  This new training was distributed to all staff in August 2021.  All City staff are required to take the IDA training module on a biannual cycle.

Additional reminders such as key chain tags listing an internal-use only phone number for City staff to report illicit discharges have also been distributed.  The new LinkedIn Learning training is documented in SAP, the City’s Information Management System database, and the City will identify needs for follow-up training.

The Permit requires the City to implement an ongoing program designed to address illicit discharges, including spills and illicit connections, into the Permittees MS4.  The program shall include procedures for characterizing, tracing and eliminating illicit discharges.

The ES Field Support Services Group and Environmental Compliance Inspection Programs work together to promote investigation and termination of illicit connections per the timelines listed above.  The ES/Environmental Compliance Section spills and complaints database is used to track the complete process of screening, investigation, referral to responsible agencies (if other than the City), and enforcement.  ES Field Support Services coordinates responses to terminate illicit connections.  Several City departments such as Neighborhood and Community Services, Code Compliance Office; ES/Science and Engineering Division; Street Operations; ES/Operations and Maintenance Division; Tacoma Water; and other agencies such as TPCHD and Ecology may be involved in both the investigation and termination of illicit connections (See Departmental Compliance and Coordination Plans).

In cases when an illicit connection may cause a severe threat to the environment or human health or when businesses are permitted under Ecology NPDES permits, the City may refer the case to Ecology to follow-up.  If a business does not respond after ES/Environmental Compliance Section staff makes a good faith and documented effort of progressive enforcement to terminate a violation, the City may partner with Ecology for enforcement.

Potential illicit discharges are discovered and investigated by ES Environmental Compliance.  ES staff investigate, document, and take corrective actions to resolve illicit discharges found through reported complaints, firsthand field observations, business inspections and stormwater monitoring information.  Tacoma Public Utilities, Environmental Compliance has an active spill response program to respond to and clean up larger spills at facilities owned and operated by Tacoma Public Utilities.  TPU reports all spills to ES Environmental Compliance who then log the report into the database for tracking.  When appropriate ES Environmental Compliance will provide onsite assistance for all spills.  ES Environmental Compliance notifies Ecology and other required agencies of all spills as required by the Permit.

ES/Environmental Compliance staffs a 24-hour on-call Source Control Representative to respond to emergency spills and complaints.  The direct call line for City staff has been included in City training for staff if they come into contact with an illicit discharge.  Environmental Compliance responds to spill complaints to ensure appropriate actions are taken to mitigate damage, document events, and complete any necessary reporting.  The Source Control Representative also responds to water pollution reports from the public water pollution hotline (TacomaFIRST 311).

The City has existing procedures for responding to spills and improper disposal to the storm system.  Some departments also participate in regional emergency response programs.

In the course of regular duties, various City staff may encounter illicit discharges or spills that are from unknown sources.  City staff may also accidentally cause spills.  All Permit required spills reporting is managed by ES Environmental Compliance.  City staff have been trained to contact ES Environmental compliance using various communication tools.  ES Environmental Compliance will investigate, responded to and report spills and illicit discharges to Ecology and other required agencies as required by the Permit.

When a major spill occurs, Ecology or other agencies may assist or manage the spill response.  Tacoma will provide assistance to these agencies as requested.   

The ES/Environmental Compliance staff uses a database (ES/Environmental Compliance spills and complaints database) to track IDDE, spill complaints, and source control inspection activities.  The database has been updated to meet the requirements stated in Appendix 14.

The referral information and final enforcement outcome for each potential illicit discharge or connection is tracked in the ES/Environmental Compliance Section spills and complaints database.