Surface Water Quality Standards

What are surface water quality standards (WQS)? How are they used? 

The goal of the federal Clean Water Act (CWA) is to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. Nebraska’s WQS describe the desired conditions of specific waterbodies and provide the foundation for a wide range of CWA programs implemented by the Department, including:

• Surface water quality monitoring and assessment programs
• National Pollutant Discharge Elimination System (NPDES) permit program
• Section 401 Water Quality Certification program
• Total Maximum Daily Load (TMDL) program

WQS also inform the CWA Section 319 nonpoint source water quality grant program by establishing the basis for identifying impaired waters, which impacts eligibility for 319 project funding. Additionally, WQS provide water quality targets for restoration and protection actions under the 319 program. 

Where are Nebraska’s WQS located? 

Nebraska’s WQS are found in Nebraska Administrative Code Title 117 - Nebraska Surface Water Quality Standards. Title 117 was most recently revised and approved in 2019.

What are the components of WQS? 

Water quality standards include three core components: 

• Designated uses 
• Water quality criteria 
• Antidegradation

Designated Uses

Designated uses are uses of surface waters for which water quality is protected. In Title 117, designated uses may also be referred to as “beneficial uses.” Title 117 recognizes the following beneficial uses: 

• Primary Contact Recreation 
• Aquatic Life 
  • Warmwater (Class A and B)
  • Coldwater (Class A and B) 
• Water Supply 
  • Public Drinking Water 
  • Agricultural
  • Industrial
• Aesthetics

Waterbodies whose uses are listed in Title 117 are termed “designated waters.” Designated stream segments are listed in Chapter 5 and designated lakes and impounded waters are listed in Chapter 6. Waterbodies are assigned multiple beneficial uses to reflect the different uses that Nebraska’s surface waters support. 

Not all waterbodies are designated in Title 117. However, certain water quality criteria still apply to these waterbodies. 

Water Quality Criteria

Water quality criteria may be either numeric or narrative and are developed to protect each beneficial use. Criteria describe the quality of water needed to be able to use the water for each specific purpose.

Numeric criteria are numbers that represent limits or ranges for specific pollutants. These criteria may be expressed as concentrations for parameters like ammonia or dissolved oxygen, or as physical properties for parameters like temperature. 

Narrative criteria are statements that describe the desired water quality condition. For example, the narrative aesthetics criteria describes that waterbodies should be “free from” human-induced pollution that causes conditions such as objectionable films and colors. 

The criteria to support each beneficial use can be found in Title 117, Chapter 4. 

Antidegradation

Antidegradation requirements provide a framework for maintaining and protecting water quality that has already been achieved. The purpose of antidegradation requirements is to protect waters from activities or discharges that will negatively impact water quality or impair designated uses of surface waters. 

Nebraska’s antidegradation requirements provide for the protection of existing uses and provide additional protections for identified waterbodies of high quality or special value. The Department’s antidegradation policy can be found in Title 117, Chapter 3