The Office of Stormwater Management promotes stormwater management along RIDOT roadways to provide safe driving and protect the health of nearby waterbodies. The OSM ensures that RIDOT projects and operations meet state and federal stormwater regulations. Specific tasks & programs include stormwater design review, Stormwater Control Plan development for the Impaired Water Program, drainage system inspection and sampling for the Illicit Discharge Detection and Elimination (IDDE) Program, drainage system asset management, and Public Education and Outreach.
RIDOT operates under a RIPDES Phase II MS4 PERMIT that regulates RIDOT stormwater discharge across all RIDOT roadways and facilities across the State. The RIDOT MS4 is an expansive system, with more than 25,000 catch basins and 3,800 outfalls that extend over 3,300 lane miles, approximately one-third of which are divided highways, the rest are rural and urban surface roads; about one-half of the system is within the MS4 Permit Area. RIDOT is authorized under a National Pollutant Discharge Elimination System (NPDES) general permit to discharge stormwater to waters of the United States through its MS4 permit.
RIDOT is pledging more than $100 million over a 10-year period to ensure compliance with the Clean Water Act and a number of remedial measures under a consent decree with the Environmental Protection Agency. This initiative will reduce pollution from stormwater flowing into Narragansett Bay and hundreds of lakes, ponds and rivers throughout Rhode Island
Download Consent DecreeAfter an audit of the RIDOT MS4 program, RIDOT was found non-compliant with several permit requirements and entered into a Consent Decree with the EPA in 2015 to develop a state-funded program to ensure future compliance. As part of this Consent Decree, RIDOT developed the Impaired Waters Program, the IDDE program, and invested in the Asset Management of drainage.
The Rhode Island Department of Transportation holds a General Permit for Stormwater Discharge from Small Municipal Separate Storm Sewer Systems (MS4) and from Industrial Activity at Eligible Facilities Operated by Regulated Small MS4s under the Rhode Island Pollutant Discharge Elimination System (RIPDES) Program. RIDOT is required to prepare an Annual Report for MS4 activities. Please follow the link below for the most recent MS4 Annual Report:
Download MS4 Annual ReportThe Rhode Island Department of Transportation entered into a Consent Decree with the EPA in 2015 to develop a state-funded program to ensure future compliance after RIDOT was found non-compliant with several permit requirements. RIDOT is required to prepare an Annual Report for Consent Decree activities. Please follow the link below for the most recent Consent Decree Annual Report:
Download Consent Decree Annual Compliance ReportThe Rhode Island Department of Transportation is required by the Consent Decree to maintain an Illicit Discharge Detection Elimination (IDDE) program to detect, investigate, and eliminate illicit discharges or flows. RIDOT is required to prepare a Bi-Annual Report for IDDE activities. The January-June report is provided below, while the July-December report is incorporated into the Consent Decree Annual Report above. Please follow the link below for the most recent IDDE Annual Report:
Download IDDE Compliance Update ReporteTool was developed to optimize stormwater permit submission for all Rhode Island Department of Transportation (RIDOT) projects and to provide cross-reference data to Rhode Island Department of Environmental Management (RIDEM) and Coastal Resource Management Council (CRMC)
The RIDOT/EPA Consent Decree requires RIDOT to submit data based upon a different stormwater credit accounting system reliant on curves instead of simulated storm events. This Consent Decree reported data must be “mined” from hydrologic and hydraulic reports and various spreadsheets. eTool was designed to simplify the process, where project specific information can be entered and/or uploaded for stormwater management design and generate customized reports for submittal to RIDOT, EPA and RIDEM.
eTool website: https://stormwaterapp.dot.ri.gov/app/
eTool Support email: DOT.eTool@dot.ri.gov
Linear Manual was developed to outline a standardized process and tools to scope and design RIDOT projects. The content of the Linear Manual provides consistent guidance for complying with stormwater treatment requirements for State RIDEM & CRMC permitting and for the Consent Decree between RIDOT, the United State Department of Justice (DOJ) and the Environmental Protection Agency (EPA).
As part of RIDOT’s overall effort to comply with the requirements of the RIPDES MS4 General Permit and the Consent Decree, RIDOT has created a program to assess its stormwater discharges located within watersheds of listed impaired waters with stormwater related impairments (as defined by Rhode Island Section 303(d) List of impaired Waters), set reduction targets, implement structural controls, also known as stormwater treatment units (STUs), as well as implement enhanced non-structural controls to reduce its contribution to know water quality impairments. For each waterbody segment impaired for stormwater related pollutants which receive RIDOT runoff, RIDOT has started developing Stormwater Control Plans (SCP). The SCPs quantify RIDOT roadway’s stormwater related pollutant contributions and identify potential stormwater treatment controls and measures that can reduce those contributions.
To determine if a SCP has been developed within a project area, refer to the RIDOT Stormwater Program Web Map.
Illicit Discharge Detection Elimination (IDDE) Program: We are committed to ensuring that RIDOT’s stormwater system is free of contaminants, such as hazardous waste, sewage, or oil and grease. When illicit discharges (i.e., discharges not composed entirely of stormwater) are identified, RIDOT will work with the responsible party and RIDEM to remove it. If you observe a potential illicit discharge, please email: dot.idde@dot.ri.gov.
We must develop, implement and enforce a program to detect and eliminate illicit discharges or flows. The management program must include a storm sewer system map showing the location of all outfalls (the point where a waste stream discharges into a body of water) and the names of all waters that receive these discharges. The map also will show the location of catch basins, manholes and pipes within the system, physical interconnections with other regulated MS4s and private property connections. Our program plan must contain procedures to identify and target priority areas and locate and remove illicit discharges.
Illicit Discharge Detection Elimination (IDDE) Program: RIDOT continues to identify, map and describe all stormwater outfalls. During the outfall identification and location process, all outfalls are survey for dry-weather discharges to potentially identify illicit connections to our state system. We sample them for temperature, pH, conductivity, and bacterial contamination, as required by the general permit. Our investigation sometimes requires us to trace flows up the inlet pipe(s) to identify where it’s coming from using smoke or dye testing or video as needed. If an illicit connection is found, RIDOT will work with the responsible party and RIDEM to remove it.
The general permit requires that to the extend allowable under state law, RIDOT must prohibit and enforce unauthorized non-stormwater discharges into the state system. While RIDOT does not have the authority to establish such ordinances, the Department relies on RIDEM for enforcement.
RIDOT has implemented an ongoing public education program with a goal to provide information about the impacts of stormwater discharges to waterbodies while highlighting steps and/or activates that can reduce the pollutants in stormwater runoff to those waterbodies.
