rpA United States
trM Environmental Protection
Office of Water
February 2021
The Biological Assessment Program Review: Assessing Level
of Technical Rigor to Support Water Quality Management
Key Questions to be Answered
	What are strengths of the technical program?
	What are the limitations of technical program?
	How to determine priorities and allocate
resources to further develop the technical
capabilities of an existing program?
	How can biological assessments be used to more
accurately define designated aquatic life uses and
develop numeric biological criteria?
	How can bioassessments be used to more fully
support water quality management programs?
Introduction and Background
Biological assessments have been a component of
state, territorial and tribal (hereafter referred to as
"state") water quality monitoring and assessment
programs for nearly four decades. Today, states
employ biological assessments as a primary
measure of Clean Water Act (CWA) goal attainment
for aquatic life.
States have used biological assessments and criteria
to more accurately define their designated aquatic
life uses, develop biological criteria, inform stressor
identification, and improve both the identification and
characterization of impaired waters (US EPA 2011,
2013 and 2016). At the same time state water quality
agencies face challenges to ensure that the best
available science serves as the backbone of their
monitoring and assessment programs.
The degree of confidence with which biological
assessment information can be used to support an
array of water quality management programs and
functions depends to a considerable degree on the
level of technical rigor. The state program review
process provides an opportunity for states and tribes
to evaluate the technical rigor of their biological
assessment program and determine how they could
better support all their CWA programs (U.S. EPA
The state program review process can help states
identify the technical strengths and limitation of their
biological assessment program and use it to develop
a plan for improvement and maintenance. As such,
the process provides detailed guidelines and
milestones by which state agencies can evaluate
and track progress in the development and
implementation of their biological assessment
What Does a Biological Assessment
Program Review Entail?
The biological assessment program review includes
an evaluation of the critical technical elements, or
components, of a biological monitoring and
assessment program and provides a forum for
agency cross-program discussions. The intent is to
provide an opportunity for state program managers
and staff to discuss how biological assessments can
better support their management programs. These
discussions can reveal opportunities for program
improvement and coordination that will foster a better
understanding about how biological assessments
can be used. An improved understanding will help
answer the "so what" question for why an agency
would allocate staff and resources for making
technical improvements.

Bioassessments can be used to:
Define goals(e.g. designated aquatic
life uses) & establish biocriteria
Assess biological condition
Inform causal diagnosis
Identify high quality waters,
prioritize restoration
Measure effectiveness of management
Maintain & Upgrade as Needed
Develop Technical Program
Define ALU &
Establish Biocriteria
Revise Actions if Needed
Monitor and Assess
Problem ID and
Prioritize Actions
Implement CWA
Assess WQS
Figure 1. Water quality management program support is enhanced with rigorous biological assessment programs.
The goal of the review is to document the technical strengths of the biological assessment program and
determine the needs for developing a more robust program. The highest level of technical development can be
thought of as a well-equipped toolbox consisting of methods, monitoring designs, and analytical techniques that
provide support for an array of water quality management information needs. An end goal of the evaluation is a
blueprint for technical program development to enhance the use of biological assessments in water quality
management programs (Figure 1). Such a plan will identify incremental steps for technical and program
development based on the strengths and gaps identified by the review.
The guiding principles of the program review are intended to help state monitoring and assessment programs
achieve levels of standardized, rigor, reliability and reproducibility that are reasonably attainable under current
technology and reasonable funding. This will, in turn, produce a more accurate, comprehensive, and cost-
effective monitoring and assessment program capable of meeting the broad goal of supporting all relevant water
quality management programs. The program review process adheres to the following principles:
Accuracy- biological assessments should produce sufficiently accurate delineations of condition so that
assessment errors are minimized;
Comparability - bioassessment programs that utilize different technical approaches should produce
comparable assessments in terms of biological condition ratings, detection of impairments, and diagnostic
Comprehensiveness - biological assessments should be integrated with chemical, physical, and other
stressor or exposure indicators, each used in their respective indicator roles, to demonstrate the
relationship between human disturbances and biological response; and,
Cost-effectiveness - cost-effective used here means that the benefits of having a rigorous and reliable
biological assessment program to support making better management decisions outweighs the intrinsic costs
of program development and implementation.

Technical Elements Used in a Program Review
The level of technical rigor is revealed by evaluating 13 critical technical elements that provide the foundation of
biological assessment design, data collection and compilation, and analysis and interpretation (Table 1). Design
includes temporal and spatial considerations, accounting for natural variability, and determining reference
condition. Data collection and compilation includes field and laboratory protocols, technical proficiency and
qualifications, and data management. Analysis and interpretation include data analysis, causal assessment,
and review procedures.
The overall level of program rigor is based on individually scoring the 13 critical technical elements based on
narrative descriptions of four levels of rigor for each element. Each of the 13 critical technical elements receive
a score based the current state of technical development. The element scores are then summed for an overall
program score with higher scores reflecting higher levels of technical development. Four levels are possible
with Level 4 being the highest and descending to Level 1 as the lowest. These levels of rigor reflect both the
technical development and capacity of a biological assessment program to provide increased support for
water quality management programs on a routine basis. The evaluation is also used to identify and
characterize any gaps in technical development that currently impede this goal and suggesting steps for
making improvements.

Technical Element
Biological Assessment
Index Period
A consistent time frame for sampling the assemblage to characterize and account
for temporal variability.
Spatial Sampling Design
Representative and adequate spatial array of sampling sites to support valid
inferences of information about the extent and severity of pollution and status both
locally and aggregated to larger areas (e.g., watersheds, river and stream reaches,
geographic region) and for supporting water quality standards (WQS) and multiple
CWA management programs.
Natural Variability
Characterizing and accounting forthe inherent make-up in biological assemblages in
response to broad scale natural factors (geology, climactic, geographical).
Reference Site Selection
Abiotic factors are primarily used to select sites that are least impacted, or ideally,
minimally affected by anthropogenic stressors.
Reference Condition
Characterization of benchmark conditions among reference sitesto establish
defensible and attainable thresholds such as numerical biocriteria and for
chemical/physical stressors.
Data Collection
Taxa and Taxonomic
Type and number of biological assemblages that are fully assessed and taxonomic
resolution (e.g., family, genus, or species).
Sample Collection
Protocols used to collect representative data in a water body including procedures used
to collect and preserve the samples (e.g., equipment, effort).
Sample Processing
Methods used to identify, and count organisms collected from a water body, including
the specific protocols used to identify organisms, subsampling, the training of
personnel, and the methods used to perform quality assurance/quality control (QA/QC)
checks ofthe data.
Data Management
Systems used by a program to store, access, and analyze collected data.
Analysis and
Ecological Attributes
Measurable attributes of a biological assemblage that are representative of
biological integrity and which provide the basis for developing biological criteria.
Discriminatory Capacity
Capability of the biological indices, metrics, and models to distinguish in increments of
biological condition along the Biological Condition Gradient (BCG).
Stressor Association
Relationship between measures of stressors, sources, and biological assemblage
responses sufficient to support causal diagnosis and to develop quantitative stress-
response relationships and thresholds.
Professional Review
Level to which agency data, methods, and procedures are reviewed by others both
within and outside the agency.
Table 1. Descriptions of the critical technical elements organized by three principal foundational categories

As the level of technical development advances, biological assessment information can be used to support
an increased number of water quality management programs on a routine basis. Over the past twenty years,
as state programs have developed more robust programs, the capability to more broadly support water
quality management programs has increased (Table 2). For example, Level 2 programs can typically support
statewide 305(b) reporting and 303(d) listing using single attainment thresholds. Whereas, in addition to
supporting 305(b)/303(d), Level 3 and 4 programs are able to more accurately characterize and set
thresholds along a biological condition gradient (e.g. excellent, good, fair, poor) rather than a single "one size
fits all" threshold. Level 4 programs routinely pair the collection of biological data for two or more
assemblages with chemical and physical parameters to better identify priority stressors and inform causal
analysis. These technical strengths produce a program that can identify high quality waters, set attainable
targets for degraded waters, prioritize restoration and protection, and track the effectiveness of the
management programs.
Table 2. An increase in the technical rigor of a state's biological monitoring program has corresponded with
increased use of the data and information to more broadly support water quality management programs.
CWA Proa ram
Specific Support Functions
Level of Riaor
Reporting & Listing
Status - delineating impairments

Trends - statewide scope, long term


Refined Uses (TALUs)

Water Quality
Standards (WQS)
Use Attainability Analyses (UAA)


Refined Water Quality Effects Thresholds




Site-specific Criteria


TMDL Development & Effectiveness

Advanced TMDLs (non-pollutants)

Causal Analysis & Diagnosis


Choosing BMPs


Measuring BMP Effectiveness


Habitat Assessment & Restoration


Identify High Quality Waters

Integrated Planning & Prioritization



CSO/SSO, Stormwater Assessment

Severity & Extent of Impairments

WET Limits & TIE/TRE


Facility Compliance Evaluation


401 Certification (404 Dredge & Fill)


 routine	) occasional	Q informal/incidental	none

Which Waterbody Types Can Be Evaluated?
All the program reviews conducted to date have focused primarily on rivers and streams. However, some of
program reviews included wetlands, lakes, and estuarine waterbody types. Some adjustments to the critical
technical elements matrix were necessary to accommodate the different aquatic waterbody types but the
process and checklist were fully transferable.
Who Are the Primary Participants?
A review should include:
	State agency program managers and staff;
	EPA regional staff; and,
	An independent facilitator with experience in the design and implementation of state biological assessment
and biological criteria programs.
The program review consists of an on-site visit at the state agency lasting 2-3 days. The state, their EPA
partners, and the independent facilitator jointly evaluate how biological assessment information is currently
used to support water quality management programs and consider the potential for future applications made
possible by a strengthened technical program. State agency representation can also involve all relevant
water quality management programs, but the monitoring and assessment and water quality standards (WQS)
programs should be included at a minimum. Follow-up reviews have been periodically conducted and used to
track progress and provide technical assistance. All reviews are done at the discretion of a state.
How Are the Review Results Provided to The State?
Following the review, the independent facilitator prepares a detailed technical memorandum that describes the
program's technical strengths, identifies the technical gaps that were revealed by the evaluation and provides
specific recommendations to the state for making improvement to its bioassessment program. This information
can be used by the state to efficiently target resources to incrementally strength the bioassessment program
and, in turn, better support water quality management programs.
Interested in More Information?
The details of the program review process are described in more detail in the document Biological Assessment
Program Review: Assessing Level of Technical Rigor to Support Water Quality Management (U.S. EPA 2013).
Please contact your EPA Regional Biological Monitoring or Biological Criteria Coordinator or Susan Jackson,
Health and Ecological Criteria Division, Office of Water (Mail Code 4304T), Environmental Protection Agency,
1200 Pennsylvania Avenue NW., Washington, DC 20460 or by email atjackson.susank@epa.gov.
U.S. EPA. 2011. A Primer on Using Biological Assessments to Support Water Quality Management. EPA 810-R-
11-01. Office of Science and Technology, Washington, DC 20460.
U.S. EPA. 2013. Biological Assessment Program Review: Assessing Level of Technical Rigor to Support Water
Quality Management. EPA 820-R-13-001. Office of Science and Technology, Washington, DC 20460.
U.S. EPA. 2016. A Practitioner's Guide to the Biological Condition Gradient: A Framework to Describe
Incremental Change in Aquatic Ecosystems. EPA 842-R-16-001. Office of Science and Technology,
Washington, DC 20460.