127.29 Stormwater

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Provisions of the Federal Clean Water Act and related state rules and regulations require a municipal separate storm sewer system (MS4) permit when the facility serves a population of 1,000 or more within an urbanized area or are located outside an urbanized area serving a jurisdiction with a population of at least 10,000 and a population density of 1,000 people per square mile or more. Furthermore, a municipal separate storm sewer means a conveyance or system of conveyances including roads and highways with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, paved or unpaved channels, or storm drains designated and utilized for routing of storm water. MoDOT has an MS4 general permit, obtained from the Missouri Department of Natural Resources (MDNR). It requires MoDOT develop and adhere to a Storm Water Management Plan (SWMP) comprised of six minimum control measures (MCMs) listed below.

1) Public Education and Outreach
2) Public Participation and Involvement
3) Illicit Discharge Detection and Elimination
4) Construction Site Runoff Control
5) Post Construction Runoff Control
6) Pollution Prevention/Good Housekeeping

MoDOT is regulated under a National Pollutant Discharge Elimination System (NPDES) general statewide storm water permit that requires MoDOT to develop and implement a comprehensive program to prevent pollution of surface waters resulting from storm water runoff.

EPG 129.27 Storm Water is intended to serve as a general guidance to assist MoDOT staff and consultants in understanding when and where to consider post-construction (i.e., permanent) best management practices (BMPs) for water quality in new construction and redevelopment projects. EPG 127.29 also serves as a guide to planners and designers, both internal and external, in the selection, design, and maintenance of post-construction BMPs in order to comply with water quality regulatory requirements. It is intended to achieve the following goals:

  • Comply with storm water permit
  • Provide an overview of important factors to be considered
  • Offer guidance in the consideration of physical, operational, and cost (capital and maintenance) characteristics of post-construction BMPs for water quality.

127.29.1 Public Education and Outreach

Permit requirement: The permittee shall implement a public education program to distribute educational materials to the community or conduct equivalent outreach activities about the impacts of storm water discharges on water bodies and steps the public can take to reduce pollutants in storm water runoff. As part of the SWMP, the public education and outreach program shall include the following information, at a minimum:

  • The target pollutant sources the permittee's public education program is designed to address;
  • Identification of target audiences for the permittee's education program who are likely to have significant storm water impacts (including commercial, industrial and institutional entities);
  • A plan to inform individuals and households about steps they can take to reduce storm water pollution;
  • A plan to inform individuals and groups on how to become involved in the SWMP (with activities such as local stream and lake restoration activities);
  • The permittee's outreach strategy, including the mechanisms (e.g., printed brochures, newspapers, media, workshops, etc.) to reach target audiences, and the projected number of how many people expected to be reached over the permit term; and
  • A plan to evaluate the success of this minimum control measure.

127.29.2 Public Participation and Involvement

Permit requirement: The permittee shall implement a public involvement/participation program that complies with State and local public notice requirements, and involve the public in the development and oversight of the SWMP, policies and procedures. As part of the SWMP document, the public involvement/participatian program shall include the following information, at a minimum:

  • How the permittee has involved the public in the development and submittal of the application and SWMP document;
  • The target audiences for the permittee's public involvement program, including a description of the types of ethnic and economic groups engaged. The permittee is encouraged to actively involve all potentially affected stakeholder groups, including commercial and industrial businesses, trade associations, environmental groups, homeowners associations, and educational organizations, among others; and
  • The types of public involvement activities included in the permittee's program. Where appropriate, the permittee must consider the following types of public involvement activities:
  • Citizen representatives on a storm water management panel;
  • Public hearings;
  • Working with citizen volunteers willing to educate others about the program; and
  • Volunteer monitoring or stream/lake clean-up activities.
  • The permittee's plan to actively involve the public in the development and implementation of their program; and
  • The method for evaluating success of this minimum control measure.

127.29.3 Illicit Discharge Detection and Elimination

An illicit discharge is defined by MDNR (10 CSR 20-6.200) as a discharge of pollutants to a Municipal Separate Storm Sewer System (MS4) that is not comprised entirely of stormwater and is not authorized under the NPDES permit. MoDOT has a statewide MS4 permit and holds a general state operating permit.

Additionally, an illegal connection is a pipe or other conveyance that has illegally been connected to MoDOT’s MS4. See additional information at EPG 127.25.8.3.2 System Attachments by Others.

Sources of illicit discharges are spills from roadway accidents, sanitary wastewater, effluent from septic tanks, improper oil disposal, laundry wastewaters, improper disposal of auto and household toxics, etc. See EPG 127.25.8.3.1 Industrial and Domestic Waste Waters on Right of Way and EPG 127.25.8.3.2 System Attachments by Others.

MoDOT is authorized to discharge the following non-stormwater sources provided that the permitting authority has not determined these sources to be substantial contributors of pollutants to the permittee’s MS4 that require a separate permit:

  • Landscape irrigation
  • Rising ground waters
  • Uncontaminated ground water infiltration
  • Uncontaminated pumped ground water
  • Discharges from potable water sources
  • Foundation drains
  • Air conditioning condensation
  • Springs
  • Water from crawl space pumps
  • Footing drains
  • Lawn watering
  • Flows from riparian habitats and wetlands
  • Street wash water
  • Bridge wash water
  • Discharges or flows from emergency firefighting activities
  • Individual residential car washing
  • Dechlorinated residential swimming pool discharges

127.29.4 Construction Site Runoff Control

This measure covers guidance presented in EPG 806 Pollution, Erosion and Sediment Control.

127.29.5 Post Construction Runoff Control

127.29.6 Pollution Prevention/Good Housekeeping

Permit requirement: The permittee shall develop and implement an operation and maintenance program that includes a training component and has the ultimate goal of preventing or reducing pollutant runoff from municipal operations. As part of the SWMP, the pollution prevention/good housekeeping program shall include the following information, at a minimum:

  • A list of all operations that are impacted by this operation and maintenance program;
  • Maintenance BMPs, maintenance schedules, and long-term inspection procedures for controls to reduce floatables and other pollutants to the permittee's regulated small MS4;
  • Controls for reducing or eliminating the discharge of pollutants from streets, roads, highways, municipal parking lots, maintenance and storage yards, waste transfer stations, fleet or maintenance shops with outdoor storage areas, and salt/sand storage locations and snow disposal areas the permittee operates;
  • Procedures for the proper disposal of waste removed from the permittee's MS4 and area of jurisdiction, including dredged material, accumulated sediments, floatables, and other debris;
  • Procedures to ensure that new flood management projects are assessed for impacts on water quality and existing projects are assessed for incorporation of additional water quality protection devices or practices;
  • An employee training program to prevent and reduce storm water pollution from activities such as park and open space maintenance, fleet and building maintenance, new construction and land disturbances, and storm water system maintenance. The permittee shall describe any existing, available materials the permittee plans to use such as those available from EPA, State or other organizations. The permittee shall describe how this training program will be coordinated with the outreach programs developed for the public information minimum measure and the illicit discharge minimum measure.

See 10 CSR 20-6.200.