Purpose
Illicit discharges inlcude nearly anything that isn't stormwater such as illegal dumping in storm drains, animal wastes, fertilizers, industrial and commercial waste, sewage, leaves, etc. Towns and instituions need to identify and remove non-stormwater discharges to their MS4.
Relevant Terms
Priority areas: means areas in the Urbanized Area and in catchments with more than 11% DCIA or catchments that discharge to an impaired waterbody. If any one of these conditions exists, it's part of the priority area.
Illicit discharge: means any unpermitted discharge to waters of the state that does not consist entirely of stormwater or uncontaminated groundwater except those discharges identified in Section 3(a)(2) of the MS4 general permit when such non-stormwater discharges are not significant contributors of pollution to a dischage from an identified MS4.
Sanitary Sewer Overflow (SSO): means a discharge of untreated sanitary wastewater from a municipal sanitary sewer.
Resources
IDDE Ordinance
Outline of the IDDE legal authority requirements.
Example IDDE ordinance available on the Legal Authorities page.
Written IDDE Program Template
Example IDDE Program template [905 KB] (developed by Fuss and O'Neill).
IDDE Workshop Materials
9/27/17 IDDE workshop presentations (below Task list)
Example Manhole Inspection form [60 KB] (developed by Fuss and O'Neill)
Task list
Where the deadline for new MS4 permittees differs from the deadline for exisiting permittees, the second deadline in parenthesis applies to new permittees.
| Activity | Deadline | Permit Page |
|---|---|---|
| Maintain inventory of known SSOs (5 year look back) | Oct 30 2017 | App B p2 |
| Citizen reporting program in place | Jul 1 2017 | 22 |
| Record illicit discharge abatement activities | Jul 1 2017 | 23 |
| Develop written IDDE program | Jul 1 2018 (Jul 1 2019) | 22 & AppB p4 |
| Establish IDDE legal authority | Jul 1 2019 | 23 & AppB p5 |
| Map all MS4 outfalls | Jul 1 2019 (Jul 1 2020) | 23 & AppB p2 |
| Complete dry weather outfall sampling (for high & low priorty outfalls) | Jul 1 2020 (Jul 1 2022) | AppB p8 |
| Detailed MS4 mapping | Jul 1 2020 (Jul 1 2022) | AppB p3 |
IDDE Workshop Materials
The NEMO program and Fuss and O'Neill presented a workshop on IDDE on 9/27/17 at Newington Town Hall. Most of the presentations were recorded. The presentation slides and recordings (where available) can be found below.
IDDE Mapping Requirements
September 27th, 2017
Presented by: David Dickson, UConn CLEAR
Presentation on the IDDE mapping requirements for the MS4 Permit.
Catchment Assessment and Ranking
September 27th, 2017
Presented by: Bill Guenther, Fuss & O'Neill
Presentation on Catchment Assessment and Ranking Procedures of the MS4 Permit.
Impaired Waters Monitoring
September 27th, 2017
Presented by: Erik Mas, Fuss & O'Neill
Presentation on Impaired Waters Monitoring under the 2017 CT MS4 Permit.
Case Study: UConn Screening and Monitoring Program
September 27th, 2017
Presented by: Mike Dietz, UConn CLEAR
Case Study presentation on UConn's IDDE screening and sampling procedure.
IDDE Dry Weather Screening
September 27th, 2017
Presented by: Bill Guenther, Fuss & O'Neill
Presentation on dry weather screening under the 2017 CT MS4 permit.