Total Maximum Daily Load (TMDL) Program
Overview
The federal Clean Water Act includes rules and programs to help states prevent and reduce water pollution.
States must identify polluted waters and plan to restore their health. Part of this plan is developing
Total Maximum Daily Loads (TMDLs) for polluted waters.
What is a TMDL?
A TMDL is the maximum amount of pollutant a water body can handle while still meeting
water quality standards.
What is included in a TMDL?
Developing a TMDL is like writing a prescription for a water body. It determines how much pollutant is there,
where it’s coming from, and how to reduce it to meet water quality standards. TMDLs set targets to meet
water quality standards that support different uses like drinking water, recreation, or agriculture.
When is a TMDL needed?
TMDLs are required for water bodies not meeting water quality standards. These are typically referred to as
“impaired waters” or “303(d) listed waters” and are identified on the state’s Section 303(d) list in the biennial
Integrated Report.
How are water bodies prioritized for TMDL development?
Water bodies are selected for TMDL development following an impaired waters prioritization strategy:
North Dakota Total Maximum Daily Load Prioritization Strategy for Vision 2 of the Clean Water Act Section 303(d) Program
Who develops TMDLs in North Dakota?
The North Dakota Department of Environmental Quality, Division of Water Quality, Watershed Management Program is
responsible for developing TMDLs for impaired water bodies in North Dakota. TMDLs must be approved by the
US Environmental Protection Agency.
What happens after a TMDL is approved?
TMDLs are implemented through local watershed projects and through water quality permits.
Local watershed projects rely on voluntary efforts from landowners and community members to reduce pollution from nonpoint sources
(runoff) identified in the TMDL. The
North Dakota Nonpoint Source Pollution Management Program (NPS Program) awards grant funding for projects addressing
nonpoint source pollution such as Best Management Practice (BMP) implementation or information and education projects.
Water quality permits are managed by the
North Dakota Pollutant Discharge Elimination System (NDPDES) program. The NDPDES program updates permit conditions to
reduce pollution from point sources identified in the TMDL (for example, discharge pipes).
How is the public involved?
Successful TMDL development and implementation ultimately depends on public participation. North Dakotan’s can directly
participate in local watershed projects and can provide comment on TMDLs and planning documents.
In January 2024 the NDDEQ released an Impaired Waters Public Survey requesting input on public water quality priorities
to guide TMDL planning. The NDDEQ plans to redistribute this survey every two years.
Public questions or concerns can contact the NDDEQ Division of Water Quality at 701-328-5210 or DEQ-TMDL@nd.gov.
What is an Advanced Restoration Plan?
Advanced Restoration Plans (ARPs), previously termed ‘Alternative’ Restoration Plans, are developed for water bodies where
sources of pollution are known and actions to address pollution are in place or planned (items a TMDL would otherwise identify
and determine). An ARP does not replace a TMDL but can help achieve water quality standards, at which point a TMDL would no longer be needed.
