Show All The Tiered Aquatic Life Use (TALU) Framework
Minnesota is working to revise its Water Quality Standards (Mn Rule Chapter 7050) to incorporate a tiered aquatic life use framework for rivers and streams in the state. The Tiered Aquatic Life Use (TALU) framework represents a significant revision to the Water Quality Standards of the state’s aquatic life use classification. The TALU framework builds upon existing water quality standards with a goal of improving how water resources are monitored and managed. Additionally, these changes advance the ability to identify “stressors” and develop effective mechanisms to improve and maintain the condition of waters in the state of Minnesota.
Updates
- External stakeholder meetings were held in January and February 2009. Additional meetings will be held before TALU advances to the rulemaking process.
- Technical development of the TALU framework is underway with a goal of completing the majority of this work in 2010. Specifically, stream classification has been nearly completed and development of the Index of Biotic Integrity (IBI) associated with each of these classes is underway. Biological Condition Gradient development is planned to be fully underway in April 2009.
What is a Tiered Aquatic Life Use Framework?
The Clean Water Act (CWA) requires states to assign beneficial uses to waterbodies and to develop water quality standards to protect those uses. Most surface waters in Minnesota are protected for aquatic life and recreation, which means they must be “fishable and swimmable”. There are two primary sub-classes of streams protected for aquatic life including a coldwater stream class (2A) and a warmwater stream class (2B).
Traditionally, aquatic life has been protected through the application of water chemistry based standards. For example, the Minnesota’s standard for dissolved oxygen in all non-coldwater streams is 5 parts per million (ppm). These chemically-based standards have been, and will remain, an important aspect of our protection measures. However, the addition of biological monitoring and biological standards will compliment and enhance our chemical standards by: 1) Providing a direct way to monitor and ultimately to protect aquatic life. 2) Providing a mechanism to identify water quality problems that chemical measurements might miss. 3) Improving our ability to accurately identify the wide diversity of stressors that impact Minnesota’s water resources.
An overview is also available in the 
TALU Fact Sheet.
Water Quality Standards
Minnesota’s water quality standards are an important tool used to protect and improve water quality. A description of the current framework for Minnesota’s water quality standards can be found on the Water Quality Standards Web page. Minnesota’s use classification system currently applies a “one size fits all” approach which does not account for natural variation in water resources. For example, North Shore streams differ naturally from streams in southwestern Minnesota largely because of broad regional differences in soils, topography, climate, and natural vegetation. To account for these natural differences, streams are classified into groups that have similar physical, chemical, and biological characteristics. By acknowledging that these natural differences exist and setting appropriate goals through stream classification it will reduce the probability of making an error in assessment or management which can result in wasted resources.
Another limitation is the use of only chemical and physical water quality standards to protect aquatic life. The use of only chemical and physical standards decouples biological monitoring data from the goal of protecting aquatic life. Measuring one, two or even a handful of chemical and physical parameters as a surrogate for protection of aquatic life will still miss others and can as a result be under and in some cases over protective of aquatic resources (Figure 2). The TALU framework relies on a combination of biological, physical, and chemical monitoring to identify potential water quality issues which is usually followed up with additional sampling to identify stressors in the watershed. The TALU framework accounts for natural variation through appropriate water body classification and relies on an adequate bioassessment program to measure aquatic life directly. Physical and chemical measures are used in their appropriate role as an indicator of potential stress. The bioassessment monitoring framework inherit in TALU is coupled with numeric biological standards which provide a direct measure of the beneficial use that is being protected. The TALU framework also produces a systematic process with a monitoring and assessment program that collects the right kinds of data which can be used at the same scale that management is being applied. As a result, monitoring and assessment work in parallel with water quality standards to develop effective standards that result in the protection of designated uses.
TALU Framework
The TALU framework is built upon a scientific model called the biological condition gradient (BCG). This model describes how biological communities change with increasing levels of stress. The BCG is based on the concept that waterbodies receiving higher levels of stress have biological communities with lower condition compared to waterbodies receiving lower levels of stress (see Figure 1 below). The BCG provides a common framework to interpret changes in biological condition regardless of geography or water resource type. It permits a more accurate determination and classification of Minnesota’s aquatic resources which improves the ability to make well-informed decisions on aquatic life designations. Another advantage of the BCG is that it provides a means to communicate existing and potential uses to the public.
To read more on the BCG see the Use of Biological Information to Better Define Designated Aquatic Life Uses in State and Tribal WQS: Tiered Aquatic Life Uses (EPA-822-R-05-001)
Figure 1. The Biological Condition Gradient
Major Goals/Outcomes of the TALU framework
The adoption of the TALU framework achieves several goals:
- Biological Standards: Incorporated into water quality standards they provide a more direct method to measure and protect biological integrity. In other words, TALU incorporates ecologically relevant endpoints into decision making.
- Natural Variability: Accounted for by appropriately classifying water bodies to improve the accuracy of water quality assessments and reduce assessment errors.
- Reference Condition: The TALU framework sets expectations based on the potential of a specific waterbody type to achieve a biological goal. This is accomplished through selection of least impacted representative reference sites within each waterbody class.
- High Quality Water Resources: TALU provides a mechanism to identify and protect high quality water resources.
- Modified or Limited Water Resources: TALU provides a mechanism to classify and assess modified or limited water resources. These include channelized streams and ditches.
Achieving these goals through the TALU framework will bring Minnesota closer to the protection and maintenance of the biological, chemical, and physical integrity of water resources in the state.
Details of TALU Goals
Biological Standards. Water quality standards in Minnesota are currently based on chemical and physical criteria such as dissolved oxygen and pH. These criteria do not directly measure the health or condition of biological communities which include fishes, insects, mussels, aquatic plants and algae. Although chemical and physical measures can tell us a lot about water quality, these criteria are essentially surrogates for a direct measure of the biological community. This can be problematic due to the large number and diversity of the stressors that impact biological communities which include chemicals, reduced oxygen, sedimentation, increased temperature, and habitat degradation (see figure 2 below). As a result, the monitoring of chemical and physical parameters for all potential stressors can become too cumbersome to be practical. Rather than measuring the wide variety of stressors, biological communities can be monitored as they are a direct measure of the response of the biota to a wide range of physical and chemical stressors. In other words, their condition is a reflection of all the impacts of multiple stressors over time.
Figure 2. The Five Major Factors that Determine the Integrity of Aquatic Resources
In other words, a major goal of the CWA and Minnesota’s water quality standards is to protect the fish, invertebrates, and plants in Minnesota’s waters. Therefore, it is sensible that we use a direct measurement of these communities to monitor their condition. Furthermore, if water resources are not suitable to support healthy aquatic communities, they may not be suitable for a variety of human activities such as fishing, swimming.
Natural Variability. One of the strengths of the TALU approach is its ability to take into account the natural variation in water resources seen across Minnesota. Minnesota’s diverse water resources mean that inflexible standards or “one size fits all” standards lead to errors in assessment and management. In other words, we need to have different expectations for different water resources. For example, streams along the North Shore are very different from streams in southern Minnesota and we would expect that the biological communities in those streams under natural conditions to be different. The TALU framework takes into account these natural differences and requires that comparisons be made between streams with similar expectations.
Reference Condition. The biological monitoring program in Minnesota relies on a “reference condition” approach to set expectations for water bodies. This approach identifies water bodies that are the least stressed and uses them to establish the “reference condition.” Once this reference condition has been established, then water bodies with unknown condition can be compared to this baseline. If the condition of the water body is lower than that of the reference condition, it would be considered impacted or stressed. The use of a reference condition relies on the development of accurate expectations for least stressed sites. However, development of these expectations is dependent on an effective waterbody classification framework that distinguishes between natural waterbody classes and changes caused by stressors.
High Quality Water Resources. Another problem with the current water quality program is that high quality resources are often under protected. At present there is a framework to protect the degradation of high quality waters called nondegradation, but there are still elements of Minnesota’s nondegredation provisions in rule that can allow considerable degradation of these waters without violating the CWA. TALU establishes a higher tier of use to protect these high quality waters. Once a water body has been established as meeting the requirements of a high quality water resource, the resource needs to be protected to maintain that status. The concept of protecting the “existing” use of a waterbody is one of the most important tenets of the CWA.
Figure 3. State of CWA program before and after implementation of TALU
Modified or Limited Water Resources. There are water resources in this State that will not in the near future meet the CWA interim goals due to legacy impacts. These legacy impacts are those impacts that preceded the CWA. This includes streams under drainage maintenance or other irreversible hydromodification that preclude attainment of goals. For example, channelized streams and ditches would be included under this category. TALU provides a mechanism to monitor and set realistic expectations for waters that are unlikely to meet goals due to legacy impacts. The expectations are fully protective the existing uses of each waterbody and recognize their historical and current site specific context. This element of TALU allows for the establishment of realistic expectations for waterbodies that have multiple and well established uses.
Some other goals/benefits of TALU adoption include:
- Monitoring of incremental improvements in water quality. This allows entities working to improve water quality to document and show progress toward a goal.
- TALU helps guide development and modification of water quality standards to produce improved standards.
- TALU merges the design and practice of monitoring and assessment with the development and implementation of water quality standards.
Stakeholder Meetings
As part of the TALU implementation and adoption process, a number of meetings will be held with internal MPCA and external stakeholders. The goal of these meetings will be to inform stakeholders and to provide a forum for discussion and input that will improve the TALU framework. These discussions will improve our ability to smoothly incorporate TALU into existing MPCA programs. Below is information on past and upcoming meetings.
External Stakeholder Informational Meetings
Five meetings were held at local MPCA offices in January 2009 to give stakeholders an introduction to TALU and provide a forum for input into the implementation of TALU. Anyone interested in TALU as well as stakeholders that are involved with or affected by water quality standards and/or TALU were invited to attend one of these meetings.
Stakeholder Meeting Locations and Dates:
- St Paul: MPCA St. Paul Board Room, 525 Lafayette Road North , January, 12, 2009, 1:00-3:30 pm
- Webcast of meeting (available live during the meeting and as an archive file after the meeting)
- Duluth: MPCA Duluth Conference Room, 525 Lake Ave. S., Duluth , January, 13, 2009, 1:00-3:30 pm
- Detroit Lakes: MPCA Detroit Lakes Conference Room, 714 Lake Ave., Suite 220, January, 14, 2009, 1:00-3:30 pm
- Marshall: MPCA Marshall Conference Room, 1420 E. College Dr , January, 15, 2009, 1:00-3:30 pm
- Rochester: MPCA Rochester Conference Room, 18 Wood Lake Drive SE., January, 16, 2009, 1:00-3:30 pm
Stakeholder Meeting Presentations
- January 12-16, 2009 (See also the Webcast of the January 12, 2009 meeting)
Stakeholder Letter (invitation to informational meetings)
External Stakeholder Workgroup Meetings
Five workgroup meetings were held in February 2009 at the MPCA St. Paul office with specific groups of stakeholders that will likely be affected by the adoption of the TALU framework. The goal was to provide a forum for discussion of issues specific to these groups that are associated with the implementation of the TALU framework. These stakeholder groups included:
- Agriculture
- Industry
- State Biologist
- Stormwater
- Waste Water Treatment Facilities
Stakeholder Letter (invitation to workgroup meetings)
Stakeholder Workgroup Meeting Presentations
Internal Stakeholder Meetings
An MPCA staff information meeting was held at the MPCA in June 2008 (see link to Webcast below). In addition, work group meetings were held with specific water quality program staff within the MPCA. These internal stakeholder meetings were held to inform MPCA staff of changes that may result from the implementation of the TALU framework and to obtain feedback. This feedback was obtained to identify issues and to consider solutions in order to facilitate the adoption of TALU into MPCA program activities.
Rulemaking
The rulemaking process is expected to begin in late 2010 or 2011.
Related Links
MPCA
- Webcast of June 2008 MPCA internal workshop
- Biological Monitoring
- Impaired Waters
- Water Quality Standards
State Web Sites
Federal Web Sites
- U.S. EPA TALU workshop modules
- An overview of the development of TALU in Ohio
- Use of Biological Information to Better Define Designated Aquatic Life Uses in State and Tribal WQS: Tiered Aquatic Life Uses (EPA-822-R-05-001)
- Biological Condition Gradient
MPCA Contacts
Will Bouchard
651-757-2333
This e-mail address is being protected from spambots. You need JavaScript enabled to view it.
