Water Quality Standards Variances

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WQS Variance Overview

A water quality standards (WQS) variance is a tool that states, territories and authorized Tribes may use to improve water quality over time.  These time-limited WQS strike a balance between providing states, territories, authorized Tribes and dischargers the time and flexibility to make incremental water quality improvements reflecting the best that can be achieved in a given time period, with accountability measures to assure the public that progress will occur.  A WQS variance can be used when it is uncertain how much progress can be achieved, but it is known that some progress is possible, and states, territories and authorized tribes don’t want to give up on working toward water quality improvement.

In 2015, the EPA published a final rule updating the federal WQS regulation to improve implementation of the Clean Water Act (80 FR 51019) in six key areas. Specifically, the EPA established the WQS variance requirements at 40 CFR 131.14 to provide a better-defined pathway for states, territories and authorized Tribes to adopt WQS variances to improve water quality, and to increase transparency and enhance opportunities for meaningful public engagement at the state, territorial, Tribal and local levels.

WQS Variances Overview Presentation

This WQS Variance Overview presentation explains the basics of WQS variances and how they can help to make water quality improvements.

WQS Variance Infographics

The EPA has developed a series of infographics to explain the basics of WQS variances, communicate their value, and describe opportunities for meaningful public engagement throughout the WQS variance process.

WQS Variances: A Clear Path to Improve Water Quality

This infographic is written in plain language to help states, territories and authorized Tribes effectively communicate to public stakeholders what a WQS variance is, how a WQS variance can be used to gain incremental improvements in water quality, and how interested stakeholders can get involved.

Strengthening Water Quality through WQS Variances

This infographic describes the value of using WQS variances to improve (i.e., “strengthen”) water quality over time. 

Your Input is Important to a Successful WQS Variance

These infographics describe how public stakeholder input can provide a state or authorized Tribe with critical information for making sound decisions early and throughout the WQS variance process. These infographics are geared toward stakeholders who are already familiar with WQS – such as members of environmental organizations and active community-based groups – to encourage meaningful collaboration and public engagement in the WQS variance process.

Coordination with the Public is Key to a Successful WQS Variance

These infographics describe how coordination with public stakeholders can provide a state or authorized Tribe with critical information for making sound decisions early and throughout the WQS variance process. These infographics are geared toward state or Tribal WQS staff to explain the value of public engagement and where opportunities for meaningful collaboration with the public can result in a successful WQS variance process.

WQS Variance Building Tool

The online tool is designed to help states, territories and authorized Tribes determine whether a WQS variance is appropriate for a particular situation and, if so, how to navigate the requirements of 40 CFR 131.14.

The EPA has also developed several resources to accompany the WQS Variance Building Tool including a collection of frequently asked questions that will help highlight what information the state, territory, or authorized Tribe should be thinking about before they begin using this tool, and a checklist for determining if a state or authorized Tribe has met the regulatory requirements for a WQS variance applicable to specific dischargers.

Ammonia WQS Variance Tools for Small Communities with Lagoon Wastewater Treatment Systems

Small communities with lagoon wastewater treatment systems typically serve fewer than 3,000 people and frequently lack the necessary financial and technical resources to comply with the CWA. Many of these communities utilize lagoon wastewater systems as the only way to treat their community wastewater. Based on an analysis completed in 2022, the EPA found that over 4,500 of these facilities are discharging lagoon wastewater systems that do not rely on more advanced supplemental technology; this is about one-quarter of the nation’s Publicly Owned Treatment Works (POTWs) regulated by the CWA’s National Pollutant Discharge Elimination System (NPDES) program.

In response to needs identified by state co-regulators and lagoon-utilizing communities, the EPA developed two suites of tools as priority actions under the EPA’s 2022-2026 Lagoon Wastewater Treatment Action Plan. The resources include:

  1. The First Stop Toolbox for Lagoons provides a user-friendly diagnostic tool that identifies technical, financial, and regulatory support resources. Small communities that are experiencing lagoon system compliance challenges or that are interested in improving facility operations can use this tool to identify solutions and best practices.
  2. The Small Lagoon Communities Economic Streamlining Tool (SLCES Tool) and the Individual Lagoon Tool (ILT) are both regulatory support tools to help states, authorized Tribes, and communities determine whether a WQS variance is appropriate for a small community experiencing lagoon system compliance challenges related to ammonia. The tools are accompanied by an implementation document, Applying the EPA’s Economic Analysis Tools to a WQS Variance for Ammonia for Small Lagoon Communities.

Water Quality Standards: Regulations and Resources

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Last updated on September 27, 2024