Clean Water Act

Clean Water Act

The Clean Water Act (CWA) regulates discharges to surface waters, with the overall goals of restoring and protecting the nation's surface waters. The provisions of the Act may be implemented by either the EPA or state agencies.

There are five primary CWA requirements to consider when planning a project:

  • "Point source" direct discharge limitations (NPDES limitation)
  • Storm water discharge standards
  • "Pretreatment" standards for sewer discharges
  • Spill prevention and response
  • Wetlands modification or dredge-and-fill activities

Point source discharge limits: The NPDES permit program; Law: CWA Section 402; Regulation: 40 CFR 122

To control point source discharges, the CWA established the National Pollutant Discharge Elimination System (NPDES) permit program. Under NPDES, point sources include effluent pipes, ditches and other human-built drain systems. A NPDES permit regulates the types and amounts of pollutants that can be directly released into waterways.

NPDES permits are issued by either the EPA or an authorized state agency. Under NPDES, a project owner must register their facility with the EPA/state, obtain a permit, install treatment systems to meet the permit limits, and conduct regular monitoring and reporting of wastewater discharges. Permit limits can be technology-based, water-quality-based, or both.

Elements of NPDES compliance can include:

  • NPDES permit application
  • Installation of various levels of control technology (such as Best Practical Technology or Best Available Technology)
  • Monthly discharge monitoring report (DMR)
  • Oral 24-hour report of non-compliance which may endanger health or the environment
  • Immediate notification of planned physical alterations or additions to facility
  • Immediate notification of any anticipated non-compliance

Stormwater discharge: Law: CWA Section 402(p); Regulation: 40 CFR 122.26 and 122.28

To address the risk of contaminated runoff from a site, facilities must obtain an NPDES permit for their stormwater drains and other runoff sources. This type of NPDES permit works much like permits obtained for other wastewater discharges. However, there are special standards for stormwater discharges.

Pretreatment standard: Law: CWA Section 307; Regs: 40 CFR 403 (General regulations and categorical standards)

If wastewater is sent to a sewer authority or Publicly Owned Treatment Works (POTW), it is exempt from NPDES wastewater permits and is instead covered by "pretreatment" regulations. There are two types of pretreatment requirements: 1) categorical standards developed by the EPA that apply to each industry, and 2) local standards developed by each POTW.

Under the pretreatment program, registration with the EPA or POTW is required and certain treatment, monitoring and reporting requirements, including the preparation of a semi-annual Sampling and Analysis Report, must be met. Among other requirements, it is not permissible to send wastewaters to a POTW which would disrupt its system or which would pass through the treatment system untreated.

Spill Prevention Control and Countermeasure Plan (SPCC): Law: CWA Sections 301 & 311, as amended by the Oil Pollution Act 1990; Regs: 40 CFR 112

The Clean Water Act has various provisions to prevent and manage spills of hazardous substances which could affect waterways. Most of these provisions have been included in the requirements of federal emergency response laws such as CERCLA and EPCRA.

One specific requirement that applies to any facility with stored oil that has the potential to be released into waterways is the Spill Prevention, Control and Countermeasure (SPCC) plan. It lays out the steps that must be followed to prevent and control an oil spill. If it is determined that "substantial harm" may result from a spill, a more specific Facility Response Plan must be prepared.

Wetlands modification and/or dredge and fill: Law: CWA Section 404; Regs: 40 CFR 230-233, 40 CFR 323-330

The Clean Water Act regulates the modification of wetland areas and the dredging and filling of waterways. Before either of these activities can be conducted at a site, a permit or authorization must be obtained from the Army Corps of Engineers. In some cases, project owners may be required to compensate or mitigate for impacts to wetland areas. Some states also have specific requirements governing activities that impact wetlands.

For more information, see: