Water Protection Program fact sheet
Division of Environmental Quality Director: Kyra Moore

Under state regulations effective October 1992, a Missouri State Operating Permit is required from the Missouri Department of Natural Resources for stormwater runoff. The law addresses pollution in rainwater runoff discharged from certain industrial facilities, construction sites and municipal storm sewers.

This technical bulletin presents an overview of the stormwater issue. The actual regulations in 10 CSR 20-6 Permits, should be consulted when making decisions on specific situations.

Missouri regulation 10 CSR 20-6.010 sets forth the requirements and process of application for construction and operating permits, the terms and conditions for the permits, clarifies the requirement of the permit program, improves its administration and brings the program into compliance with the latest federal regulations 44 CFR 32.854 (1979).

Since 1948 there have been a number of new amendments to the original Federal Water Pollution Control Act. In 1972 amendments were made to the Federal Water Pollution Control Act of 1948, which then became known as the Clean Water Act. The focus of the act is to restore and maintain the physical, chemical and biological properties of the nation’s waters.  

The 1972 amendments added the structure for regulating discharges of pollutants and required that a permit be obtained prior to any discharge of water that containing a pollutant. After the Clean Water Act was ratified in 1972 the U.S. Environmental Protection Agency performed a study called Nationwide Urban Runoff Program. From this study it was determined sediment was the nation’s number one water pollutant. What was most surprising was the sediment polluting the waters was primarily from residential, commercial and industrial construction activities.  

In 1987 the federal Clean Water Act was amended to include the regulation of certain stormwater classes which lead to the establishment of the National Pollutant Discharge Elimination System (NPDES) permitting program. The NPDES program requires the implementation of controls designed to prevent harmful pollutants from being washed down by stormwater runoff into local water bodies.  

EPA delegated authority for the NPDES permitting program to the department in 1974. Although the federal government oversees and reviews the Missouri State Operating Permit program, it is the state which issues and enforces the permits. Under this authority, Missouri has published its own stormwater regulations (10 CSR-20.6.200).

Missouri Stormwater Permits
In Missouri, the stormwater permitting requirements are being handled in two ways: general and site-specific permits. When applicable, a general permit is written to cover industries identified in the law as needing permits. These permits cover a group of similar discharges under one permit. Facilities with business practices that cannot be covered under a general permit are required to obtain a site-specific permit.

General Permits
General permits cover a group of similar discharges under one permit. These permits simplify the process for dischargers to obtain authorization to discharge, provide permit requirements for any discharger that applies for coverage, and reduces the administration workload for NPDES permitting authorities. General permits for stormwater management require owners or operators of certain facilities or those with land disturbance projects to manage their practices in ways that are beneficial to the environment and to Missouri streams. These permits generally specify that stormwater discharges shall not cause water quality violations. 

By written request to the department, a general permit may be drafted for a specific industrial type not currently covered under a general permit. Such a request is typically initiated by an organization on behalf of a group of industries. Organizations interested in submitting a petition to request the development of a general permit should contact the department regarding the necessary information needed in making the determination. 

With exception of the Missouri State Operating Permit for Land Disturbance, an individual shall supbmit the appropriate application forms directly to the department. The application and issuance of land disturbance permitting is completed through an electronic process. The Missouri Department of Natural Resources' regional offices can provide technical assistance on environmental issues and general permitting requirements. A map of the regional offices along with contact information is available online

Site Specific Permits
Many facilities have business practices that cannot be covered under a general permit and so are required to obtain a site-specific permit. A site-specific permit may be for a business that stores toxic materials or large amounts of potential contaminants on site that are exposed to rainfall or that need close monitoring. These permits require additional attention from the permit writer in determining how existing practices effects the environment and what requirements will be needed to ensure the environment and Missouri streams are not adversely impacted. 

There are exemptions written in the stormwater regulations. For example, certain agricultural discharges, sites that disturb less than one acre and not part of a larger common plan, certain linear, strip or ribbon construction or maintenance operations and landfills that have been closed under conditions approved by the department. Stormwater discharges to combined sewer systems are exempt. The stormwater regulation 10 CSR 20-6.200 (1)(B) should be referred to  for specific exemptions.  

Three Categories of Stormwater Permitting
The law requires that stormwater permits be issued in three broad categories:

  • Land Disturbance Permits for land disturbance activities of 1 acre or greater, or less than 1 acre when part of a larger common plan of development or sale, 
  • Municipal Separate Storm Sewer System (MS4) permits for municipalities that come in under Phase I or Phase II regulations or  other criteria that could designate a municipality into the program, and
  • Industrial Stormwater Permits for industries with certain Standard Industrial Classification (SIC) codes that are required to obtain permits for their process water and stormwater discharges. All regulated facilities and/or projects are required to obtain the required permit, a general permit or a site-specific permit, prior to beginning the regulated activity. 

Land Disturbance Permit
The primary pollutants of concern from construction activities are silt and sediment, but other pollutants such as oils and grease, vehicle fluids, and debris are present as well. The removal of vegetation exposes bare soil which is much more vulnerable to erosion, resulting in sediment moving into receiving waters. Construction activities increase pollutant loads and runoff. Sedimentation can destroy aquatic habitat and high volumes of runoff can cause stream bank erosion. The volume and rate of runoff are typically increased, providing a larger capacity to transport pollutants to rivers and lakes. 

State law requires land disturbance activities of one acre or greater, and those less than one acre if part of a common plan of development or sale to be covered under a permit prior to the onset of construction activities. There are two general permits for land disturbance, the MOR100 permit, which covers land disturbance activities on land owned by a city, county, state or federal agency, and the MORA permit which covers all other land disturbance activities in the state. The application and issuance of the MORA general permit is an electronic process. To apply for the MOR100 general permit, complete Form E - Application for General Permit and Form G - Application for Stormwater Permit available in the department's online document search. Submit the completed applications along with the appropriate fee to the department.  

The primary requirement of the land disturbance permit is development and implementation of a Stormwater Pollution Prevention Plan. The purpose of the plan is to ensure the design, implementation, management and maintenance of best management practices in order to reduce the amount of sediment and other pollutants in stormwater discharges. The plan should be kept on-site and does not need to be sent to the Missouri Department of Natural Resources unless specifically requested. The plan must be amended when changes in facility design, construction, operation or maintenance occur. The permittee shall select, install, use, operate, and maintain appropriate best management practices for the permitted site. In addition to the Stormwater Pollution Prevention Plan, the MOR100 permit requires quarterly reporting of land disturbance projects.

Municipal Separate Storm and Sewer System (MS4) Permits
An MS4 is a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) designed or used for collecting or conveying stormwater, which is not a combined sewer and is not part of a publicly owned treatment works. MS4s are owned or operated by a state, city, town, borough, county, parish, district, association, or other public body including special districts under state law, such as a sewer district, flood control or drainage district, or similar entity. Regulated MS4s are required to apply for permit coverage from the department under Phase I (medium to large MS4s) or Phase II (small MS4s) regulations. 

In Missouri, three cities (Kansas City, Springfield, and Independence) each over 100,000 in population came under Phase I regulations in the late 1990s: Phase I communities must implement a documented stormwater management program plan and provide jurisdiction-wide stormwater quality assessments and industrial runoff management program as stated in 10 CSR 20-6.200 (4). The MS4 must complete annual report forms and submit them to the department.     

MS4s that fall under the Phase II regulations are communities with populations of 1,000 or more and located within official urbanized areas as defined by the U.S. Census Bureau. Communities located outside of Missouri’s nine urbanized areas are also regulated; primarily those communities with populations of 10,000 or more. Communities regulated as a Phase II MS4 are required to develop and maintain a written five-year stormwater managment program plan in conjunction with the permit. A list of regulated MS4s is available online.

Communities servicing stormwater runoff entirely through combined sewer systems are regulated under sanitary sewer system regulations and exempt from MS4 regulation.

Industrial Activity Permits
Missouri’s industrial activities may need to obtain a general stormwater permit or a site-specific permit for discharges to waters of the State or to a MS4. If the activity does not discharge to either, no permit is needed. If it does discharge to one or both and if the industrial activity is listed among the regulated categories and meet certain requirements as outlined in 10 CSR 20-6.200 (2), a permit is required.

An industrial activity may be excluded from a stormwater permit for if the activity does not expose materials to stormwater as stated in 10 CSR 200 (1)16. Qualified permit holders as well as new applicants that qualify must submit a completed EPA form Stormwater Discharges from Industrial Activities Conditional “No Exposure" Exclusion to the Missouri Department of Natural Resources.

Industrial Classifications
To determine if an industry is covered under the law, stormwater regulations use the Standard Industrial Classification (SIC) code system. The U.S. Office of Management and Budget devised this classification code to cover all economic activities.

The first group (Group 1) of identified SIC codes are required to obtain a permit to discharge stormwater, unless certified as having no exposure of materials to stormwater.

 Group 1 - Industry SIC Code

  • Metal Mining 10xx
  • Coal Mining 12xx
  • Oil and Gas Extraction 13xx
  • Mining and Quarrying of Nonmetallic Minerals 14xx
  • Food and Kindred Products 20xx
  • Tobacco Products 21xx
  • Textile Mill Products 22xx
  • Apparel and Other Finished Products 23xx
  • Lumber and Wood Products 24xx
  • Furniture and Fixtures 25xx
  • Paper and Allied Products 26xx
  • Printing, Publishing and Allied Industries 27xx
  • Chemical and Allied Products 28xx
  • Petroleum Refining and Related Industries 29xx
  • Rubber and Miscellaneous Plastic Products 30xx
  • Leather and Leather Products 31xx
  • Stone, Clay, Glass and Concrete Products 32xx
  • Primary Metal Industries 33xx
  • Fabricated Metal Products 34xx
  • Industrial and Commercial Machinery and Computer Equipment 35xx
  • Electronic and other Electrical Equipment and Components 36xx
  • Transportation Equipment 37xx
  • Measuring, Analyzing and Controlling Instruments 38xx
  • Miscellaneous Manufacturing Industries 39xx
  • Public Warehousing and Storage 4221-4225

The following industrial types are subject to the same requirements as Group 1:

  • Hazardous waste treatment, storage or disposal facilities; however, hazardous waste generator sites that accumulate wastes on-site for less than 90 days are exempt.
  • Landfills, land application sites and open dumps.
  • Recycling facilities including metal scrap yards, battery reclaiming, salvage yards and automobile junk yards; however, recycling collection centers are exempt from the regulations.
  • Steam electric power generation facilities including coal handling sites.
  • Domestic sewage and wastewater treatment facilities with a design flow of 1 million gallons per day or more, and disposal areas.

The second group (Group 2) of identified SIC codes are required to obtain a stormwater permit only for those portions of the facility that are involved in vehicle maintenance (including vehicle rehabilitation, mechanical repairs, painting, fueling and lubrication) equipment cleaning operations, and airport deicing. 

Group 2 - Industry SIC Code

  • Railroad Transportation 40xx
  • Local and Suburban Transit and Interurban 41xx
  • Highway Passenger Transportation
  • Motor Freight Transportation and Warehousing 42xx
  • United States Postal Service 43xx
  • Water Transportation 44xx
  • Transportation by Air 45xx
  • Petroleum Bulk Station Terminal 5171

If a general permit has been written for an industry, the applicant should complete Missouri Form E - Application for General Permit and submit it with the appropriate fee. If the industry is of such a nature that a site-specific permit is required, then the applicant should submit the appropriate fee depending on calculated flow at the site’s outfalls, and complete Missouri Form A - Application for Construction or Operating Permit along with either Missouri Form C - Application for Discharge Permit or EPA's Application Form 2F Stormwater Discharges Associated with Industrial Activity.

For more information, please contact the appropriate Missouri Department of Natural Resources’ regional office. You may also contact the Water Protection Program at 800-361-4827.

Nothing in this document may be used to implement any enforcement action or levy any penalty unless promulgated by rule under chapter 536 or authorized by statute.

For more information