The Connecticut Total Maximum Daily Load (TMDL)

- Action plans to restore or protect water quality grouped photos of river, fishing, child
Download a TMDL (listed by segment ID)
The Bantam Lake Statewide Lake Nutrient TMDL Core Document and the Bantam Lake TMDL have been approved by the Environmental Protection Agency! CTDEEP's Response to Comments are now available. For more information visit the Bantam Lake Watershed Project Webpage.

What is a Total Maximum Daily Load (TMDL)?

A TMDL is an Action Plan used to address pollution, kind of like a budget.  Any waterbody that is overspending its daily budget for a substance is considered to be polluted or impaired.  Any waterbody that is spending less than its daily budget for a substance has good water quality which should be protected.  TMDLs provide the framework for restoring impaired waters by establishing the maximum amount of a pollutant that a waterbody can receive without adverse impact to fish, wildlife, recreation, or other uses.  A TMDL can also be used to set a budget to protect waters with good quality.

The TMDL Process

TMDL Process
The Connecticut Water Quality Standards
The Connecticut Water Quality Standards (WQS) form the foundation of Connecticut’s water management programs, designated uses and related classifications of Connecticut’s water resources.
Monitor Water Quality
The CT DEEP Water Monitoring Program conducts ambient monitoring of the State’s waters on a rotating basis, called the Ambient Water Quality Monitoring Program Strategy.
Evaluate CT's Waters
Every two years each State is required to report those waterbodies that are overspending their daily budget (impaired) for a substance listed in the Integrated Water Quality Report (IWQR). The IWQR lists all of the waterbodies or stream segments which are impaired, and identifies the cause and use which is impacted.

Develop Action Plans to Restore or Protect Water Quality

  • Action plans describe the water quality conditions, identify goals and steps to restore or protect water quality.
  • An action plan can be a TMDL or an alternative plan selected through IWQR and the Integrated Water Resource Management (IWRM) program which is a new approach to address the existing goals of protecting and restoring Connecticut's waters. This process allows Connecticut to identify areas for action plan development based on state-specific concerns and provides sufficient time to develop plans using flexible approaches under existing TMDL authority and doesn't create new regulations. Final TMDLs and Action plans form the basis for implementation activities. Proposed TMDLs go through a public review process.     
 Work with Partners
  • Many watershed groups and local organizations already strive to make CT waterbodies clean and healthy.  CT DEEP would like to work together to accomplish our clean water goals.  We need your participation! Contact Connecticut’s Watershed Management Program! The Watershed, Lakes, and Nonpoint Source Program Staff are here to work with you on water-related projects and issues statewide. Please feel free to contact them about the ways in which they may be able to assist you. Partners can be towns, industries, government agencies and advocacy groups.
  • Volunteer! CT DEEP currently coordinates two programs for volunteers interested in monitoring streams and rivers in their towns or watersheds.
      Implement Actions
Once a plan is established and approved, it is implemented to its appropriate setting including:
  • Permits - Before an industry can discharge a substance to a CT waterbody it must be permitted to do so by CT DEEP.
  • Remediation Plans -The Remediation Regulation Standards are used to determine the framework to clean up contaminated sites in CT. 
  • Watershed Plans – Development and implementation of these plans to focus on addressing a specific nonpoint source impairment. identified on DEEP's Integrated Water Quality Report to Congress, with the ultimate goal of reducing or removing the impairment, so the waterbody can meet Water Quality Standards, and be removed from the list. 

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For more information, contact us at (860) 424-3020.

Content last updated March 16, 2022