NPDES Introduction

Contact Information for NPDES Permits

This page can be accessed as www.mi.gov/deqnpdes.

Water quality protection has been a long-standing concern in Michigan. An effort to protect Michigan's water resources began early in the twentieth century, with the enactment of the Michigan Water Resources Commission Act (Act 245) in 1929. 

The NPDES permit process was initiated by The Federal Water Pollution Control Act amendments of 1972. The purpose of the program is to control the discharge of pollutants into surface waters by imposing effluent limitations to protect the environment. Authority to administer this program was delegated to Michigan by the Environmental Protection Agency (EPA) in October of 1973. Thus, Michigan was one of the first states to be authorized to carry out this program.  Currently, authority for NPDES permit issuance rests with the Michigan Department of Environmental Quality.

Perhaps the most notable goal of the Act was the elimination of discharge of pollutants into navigable waters by 1985.  This goal was not realized, but remains a principle for establishing permit requirements.  The Act had an interim goal to achieve "water quality which provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water" by July 1, 1983.  This is more commonly known as the "fishable, swimmable" goal.

The enactment of the 1972 amendments marked a distinct change in the philosophy of water pollution in the United States.  The amendments maintained the water quality-based controls, but also included technology-based control strategies.   The treatment technology-based discharge standards are promulgated by the U.S. Environmental Protection Agency (EPA) and are based on the category of the facility.   Dischargers are placed in categories based on industrial processes or on the type of wastewaters generated.  As treatment technology improves, these federal standards are expected to become more restrictive in order to progress toward the goal of zero discharge.  As permits expire they must be reissued with limits reflecting the most recent treatment technology standards.  

The Act also contains four important principles:

  1. The discharge of pollutants to navigable waters is not a right.
  2. A discharge permit is required to use public resources for waste disposal and limits the amount of pollutants that may be discharged.
  3. Wastewater must be treated with the best treatment technology economically achievable - regardless of the condition of the receiving water.
  4. Effluent limits must be based on treatment technology performance, but more stringent limits may be imposed if the technology-based limits do not prevent violations of water quality standards in the receiving water.

The first round of NPDES permits issued between 1972 and 1976 provided for control of a number of traditionally regulated pollutants, but focused on 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), pH, oil and grease, and some metals, by requiring the use of the Best Practicable Control Technology currently available (BPT).  The Act established a July 1, 1977, deadline for all facilities to be in compliance with BPT.  Additionally, the Act established the compliance deadline for installing Best Available Technology Economically Achievable (BAT) as July 1, 1983.  Most of the major permits issued to industrial facilities in the first round of NPDES permitting contained effluent limitations based on Best Professional Judgment (BPJ) because regulations prescribing nationally uniform, technology-based effluent limitations were generally unavailable. 

The 1977 amendments to the legislation, known as the Clean Water Act (CWA) of 1977, shifted emphasis from controlling conventional pollutants to controlling toxic discharges.  This era of toxic pollution control is referred to as the second round of permitting.  The concept of BAT controls was clarified and expanded to include toxic pollutants.  Hence, the compliance deadline for BAT was extended to July 1, 1984.  The conventional pollutants (BOD5, TSS, pH, fecal coliform and oil and grease) controlled by BPT in the first round of permitting were now subject to a new level of control, termed Best Conventional Pollutant Control Technology (BCT).  The compliance deadline for meeting BCT was also July 1, 1984.

In addition to treatment technology-based standards, the Clean Water Act also required that minimum receiving water quality standards be achieved.   Water quality standards are promulgated by the states.  The Michigan standards are designed to not only protect for aquatic life ("fishable") and recreation ("swimmable"), but also for all other uses of the receiving waters, including agriculture, public and industrial water supply, and navigation.

On  February 4, 1987, Congress amended the CWA with the Water Quality Act (WQA) of 1987.  The amendments outlined a strategy to accomplish the goal of meeting water quality standards set by the States.  The WQA required all States to identify waters that were not expected to meet water quality standards after technology-based controls on point sources have been imposed.  The State must then prepare an individual control strategy to reduce toxics from point and nonpoint sources in order to meet the water quality standards.  Among other measures, these plans were expected to address control of pollutants beyond technology-based levels.

The WQA once again extended the time to meet BAT and BCT effluent limitations.  The new compliance deadline was no later than March 31, 1989.   The WQA also established new schedules for industrial and municipal storm water discharges to be regulated by NPDES permits.  Industrial storm water discharges must meet the equivalent of BCT/BAT effluent quality.  Discharges from municipal separate storm sewer systems (MS4) require controls to reduce the discharge of pollutants to the maximum extent practicable (MEP).  Additionally, the WQA requires EPA to identify toxics in sewage sludge and establish numerical limits to control these pollutants.   The WQA also established a statutory anti-backsliding requirement that will not allow an existing permit to be modified or reissued with less stringent effluent limitations, standards, or conditions than those already imposed.  There are a few situations under which exceptions can be made, including when the permittee was unable to achieve the previous permit limits and when production is increased.

The issuance of an NPDES permit or certificate of coverage does not authorize violation of any federal, state or local laws or regulations, nor does it obviate the necessity of obtaining such permits, including any other DEQ permits, or approvals from other units of government as may be required by law.