Consolidated Assessment and Listing Methodology (CALM)
The Federal Clean Water Act Section 305(b) water quality reports and Section 303(d) impaired waters lists are highly visible ways for states to communicate to the public about the health of the nation's waters. Section 305(b) requires states to assess and periodically report on the quality of all the waters of their state. Section 303(d) further requires the states to identify from this assessment a list of Impaired Waters where specific designated uses are not fully supported, and where restoration and protection efforts beyond conventional technology-based controls are necessary to address water quality issues.
For these waters, the states must consider the development of a Total Maximum Daily Load (TMDL) approach to reduce the input of the specific pollutants that restrict water uses.
The U.S. Environmental Protection Agency encourages integration of monitoring, assessment and listing efforts and the consolidation of methodologies for Section 305(b) and 303(d) activities. In response the New York State Department of Environmental Conservation's Division of Water has developed this Consolidated Assessment and Listing Methodology, which outlines in considerable detail the process the Department follows in monitoring and assessing the quality of New York State waters. The Methodology also improves the statewide consistency of assessment and listing decisions.
The Methodology consists of three (3) separate parts.
- The Monitoring Strategy (pdf, 822 kb) provides an overview of the NYS DEC water quality monitoring program.
- The Assessment Methodology (pdf, 520 kb), revised during the 2008 reporting/listing cycle, details the evaluation of monitoring data and information to determine levels of water quality and use support. (The most recent changes to the Methodology are shown in blue text.)
- The Listing Methodology (pdf, 363 kb), revised during the 2008 reporting/listing cycle, outlines the identification and prioritization of waters that do not meet water quality standards or support designated uses. (The most recent changes to the Methodology are shown in blue text.)