Member Pipeline - Regulatory - Alert (RA 02-18)
To: Members & Affiliates, Water Quality Committee
From: National Office
Date: September 13, 2002
Subject: EPA Publishes First Edition of the Consolidated Assessment and Listing Methodology (CALM) Guidance Document
Reference: RA 02-18
Action Please By:
October 7, 2002
Printer friendly versionThe U.S. Environmental Protection Agency (EPA) in August 2002 published the first edition of its long-anticipated Consolidated Assessment and Listing Methodology (CALM). The document can be downloaded at http://www.epa.gov/owow/monitoring/calm.html. Originally expected to be released in 2001, the CALM document was delayed due to Agency concerns regarding major aspects of the document, and even now has been issued with three chapters either still under development or saved as placeholders for a later version of the guidance. The purpose of CALM is to provide states with a framework for improving the methods used to determine the status of attainment of all waters within their jurisdiction and to identify those waters that are impaired. The document also is intended to assist states in developing their integrated reports of state waters and their required assessment and listing methodologies in accordance with EPA’s 2002 Integrated Water Quality Monitoring and Assessment Report Guidance (see http://www.amsa-cleanwater.org/private/regalerts/ra01-21.cfm). The states are required to submit their next list of impaired waters by October 1.
During the initial phases of CALM, AMSA met with lead EPA staff and participated in each of several development meetings in the fall of 2000 to convey the issues and concerns of the publicly owned treatment works (POTW) community. The National Office submitted comments to the Agency on an earlier draft outline of CALM in December 2000, a copy of which can be accessed via the AMSA web site at http://www.amsa-cleanwater.org/private/legreg/outreach/CALM12-14-00.pdf. In March 2002, AMSA, in concert with the Federal Water Quality Coalition and the American Farm Bureau, released its own set of recommendations on the listing and assessment process. The document can be downloaded at http://www.amsa-cleanwater.org/advocacy/wqmar/ on the AMSA web site.
Member Feedback Encouraged
The Agency is welcoming comments from all interested parties,
although no deadline for submittal was specified. Specific comments are
encouraged on how the document may be improved and on case studies and examples
where methods are working or need to be modified. It is EPA’s intent to revise
CALM as needed in the future. We encourage you to review this guidance and
submit comments or specific case studies by Thursday, October 10 to
AMSA c/o Will Pettit at
wpettit@amsa-cleanwater.org or 202/833-3280. AMSA will continue to track
the progress of CALM, and submit comments based on member feedback.
Summary of CALM
EPA formatted the CALM guidance as a series of questions needed
to document each state’s listing methodology. It is split into three parts. Part
A deals with water quality standards (WQS) attainment decisions and
identification of impaired waters, and is organized according to the types of
data that may be used to support these decisions. Part B involves designing a
comprehensive monitoring program to assess the extent to which waters are
attaining WQS and to identify impaired waters. Part C, still under development,
will detail approaches for reporting on WQS attainment for the full inventory of
waters in the 303(d) list.
The following is a summary of significant aspects of the current CALM chapters.
Part A:
Chapters 3-9 include information on WQS attainment decisions. Chapter
3 provides an overview of the process used to assess WQS attainment and identify
impaired waters, including the type of data used to demonstrate attainment
status with different categories of designated use (i.e., aquatic life,
recreation, public water supply, and fish and shellfish consumption). This
chapter includes a specific recommendation that, regardless of the type of WQS
being assessed, the state should articulate the types of data or indicators used
to determine attainment status and the thresholds used to distinguish attainment
from nonattainment. Chapter 3 also includes a chart (see p. 3-9) which explains
how the Independent Applicability Process is used to reconcile
conflicting results among different data sets.
Each of the subsequent chapters addresses the use of different types of data in making attainment determinations.
- Chapter 4 – Chemical Data: The chapter provides a broad overview of how chemical data is used to establish state WQS and to determine attainment status. A comprehensive list of state web sites is included (see p. 4-4) to facilitate access to each state’s WQS. Among the recommendations on the use of chemical data is that “the state should ensure that their sampling design program be implemented in such a way that each sample represents the variable conditions extant in the target water(s) at the locality.” States should also better define minimum data quality requirements, including information on appropriate sample size and monitoring design, sample collection and handling protocols, analytical methods and detection limits, quality control (QC) procedures, and data management. The chapter also includes recommended procedures for assessing data quality (p. 4-12), interpreting chemical data to assess WQS attainment (p. 4-16), and balancing attainment determinations with typical decision errors.
- Chapter 5 – Biological Data: For evaluating the types of biological data used, EPA utilizes a rating system which ranges from Level 1 (high degree of uncertainty) to Level 4 (relatively high level of certainty in assessment, and the highest rigor and quality). EPA indicates that “a highly developed biological assessment program, coupled with biologically based aquatic life uses and numeric biocriteria to protect those uses, constitutes the most effective combination for assessing and managing aquatic life resources, and should be the goal of all states.” The Agency recommends that states use biological assessments to refine, or tier, their aquatic life uses by articulating appropriate ecological expectations for state waters (e.g., reference conditions) and specifying goals for individual waterbodies (e.g., tiered, designated aquatic life uses).
The guidance summarizes the most common approaches for integrating biological data into state WQS programs (p. 5-4), and describes how bioassessment data can be used in each type of state program. The document also includes recommendations on the level of rigor necessary for use of Level 1-4 data in key components of a biological assessment (e.g., reference conditions, temporal coverage, indicator assemblage, and precision of assessments) (p. 5-8). In addition, this section describes the overarching strategy for analysis of biological data (p. 5-25), the multimetric approach to analyzing data (p. 5-28), the combination of metrics and multiple discriminant analysis (p. 5-30), and a modeling approach using observed/expected taxa (p. 5-31).
- Chapter 6 – Toxicity Data: The guidance encourages states to use the data quality objectives (DQO) process to define minimum-quality data requirements for using toxicity data. States are also encouraged to document required procedures that ensure the quality of the data collected, including information on sample collection and handling protocols, use of standardized methods, QC procedures, and data management. EPA recommends the use of a tiered approach to determine whether toxicity data are acceptable (p. 6-6). In addition, the guidance includes a hierarchy of toxicological approaches for evaluation of aquatic life use attainment (p. 6-8).
- Chapter 7 – Bacteria Data: This chapter provides a summary of the different state bacteria indicators for standard designated uses such as primary and secondary contact recreation, shellfish harvesting, and public drinking water sources (p. 7-4). Here again, EPA recommends that states use a tiered approach for WQS attainment determinations, including steps for ensuring data quality (p. 7-6) and for screening suspect data. Once the state possesses data that meets its data quality objectives, the Agency suggests the development of implementation policies to explain how bacteria data is used, including the following factors: 1) desired confidence levels in the data used to support the decision, 2) appropriate size of confidence intervals to control the precision of the data set, and 3) minimum sample size to control for the potential to conclude that a waterbody is attaining a standard when insufficient data have been collected to credibly detect nonattainment. For protecting recreational beaches, EPA suggests that predictive models be used only when the state has collected rainfall data over time and has calibrated and verified the rainfall model. If the model then accurately demonstrates non-attainment under certain conditions and rainfall events, it can be used accurately for making attainment decisions. If the state only uses the model for precautionary closures, the data and model may not be appropriate for making attainment decisions.
- Chapter 8 – Habitat Data: EPA acknowledges that although habitat quality is recognized as a limiting factor for fisheries and aquatic biota, there is no consensus on what specific components of physical habitat structure should be assessed for attainment. The guidance identifies and describes procedures to assess seven general physical habitat attributes important in influencing stream ecology, including stream size/channel dimensions, channel gradient, channel substrate size and type, habitat complexity and cover, riparian vegetation cover and structure, anthropogenic alterations, and channel-riparian interactions (p. 8-3). In terms of data quality assessment and documentation, the guidance recommends that standard operating procedures (SOPs) that describe in detail the criteria for assessing physical habitat, and a QA/QC plan that identifies accountability throughout the assessment process, be developed to minimize bias, reduce error, and maintain data integrity. This chapter includes a table categorizing habitat assessment approaches based on the level of rigor involved in the protocol (p. 8-7).
In addition, EPA specifies that any credible and feasible approach for use of habitat indicators should include a clear statement of the use of habitat indicators within the context of the CWA and relevant state laws and if not documented in the WQS, should be documented in the assessment and listing methodology (p. 8-11). States should also ensure that use of habitat indicators is at an appropriate scale and stratification to be meaningful in comparison to reference conditions (see p. 8-13 for recommendations on establishing reference conditions), and that there is an emphasis on quantitative measures.
Part B:
This section of the document comprises two chapters, both of which detail
integrated monitoring design for comprehensive assessment and identification of
impaired waters. Chapter 10 provides information on selecting metrics or
indicators of WQS attainment, including point, nonpoint, geological, and
hydrological sources. Chapter 11 describes monitoring network design and
implementation scenarios, addressing such issues as how the state defines its
waters, what monitoring designs are used to support the state’s decision making
needs, and how implementation of the monitoring program achieves stated
objectives.
- Chapter 10 – Selecting Metrics/Indicators of WQS Attainment: As a starting point, the guidance recommends that the state have in place a mechanism for interpreting data on water quality indicators within the context of its WQS. EPA clarifies that one of the key aspects of the state’s listing and assessment methodology is the identification of core or first-tier indicators, including physical, chemical, or biological measures. The guidance includes a suggested set of initial indicators for state consideration which was developed by the Intergovernmental Task Force on Monitoring Water Quality (p. 10-3).
- Chapter 11 – Monitoring Network Design/Implementation Scenarios: When the state defines the waters to be included in the monitoring program, EPA suggests two key steps: defining the target population and developing the sampling frame (p. 11-2). As part of the state’s assessment methodology development, EPA recommends a brief description of the monitoring designs used to generate water quality results be included. This description should detail all aspects of monitoring activities, including defining the target population, selecting sample locations, selecting indicators to measure, defining how samples are collected and analyzed, and analyzing and presenting data and results. The guidance identifies three basic design options which can be used to determine the extent of attainment or nonattainment of state waters, including census (measurements are taken for every element in the population), judgmental (measurements are taken at waterbody locations selected on the basis of experience of experts, and results are extrapolated on the basis of expert judgment), and statistical survey (measurements are taken of a randomly selected sample of the target population, and statistical inferences about the distribution of values for the entire population are drawn from the sampled units).
EPA also suggests that implementation plans be established in addition to the monitoring design network. The guidance identifies several options for tailoring implementation plans to waterbody types, individual basins, and applicable designated uses (p. 11-1), and suggests a five- or six-year monitoring schedule for the first two types.
Part C:
Chapter 12, not yet published, will include information on integrated data
management and documentation.
For more information on CALM, please contact Will Pettit at 202/833-3280 or wpettit@amsa-cleanwater.org.