DEC takes a data driven approach to water resource management. High quality data and a deliberate approach to monitoring, assessment, research, and reporting provide scientific foundation to inform effective management strategies. DEC clearly defines methodologies for data collection and assessment of attainment of best uses. DEC’s waterbody assessments, research publications, and waterbody reports, are publicly available through resources and links provided below.
Data Analysis/Assessment using Core and Supplemental Water Quality Indicators
DEC uses its Consolidated Assessment and Listing Methodology (CALM) to assess the attainment of water quality standards based on analysis of various types of data (chemical, physical, and biological) from various sources, for all New York State waterbody segments.
DEC’s CALM is used to assess the quality of the state’s waters relative to the attainment of DEC water quality standards and to report assessment results to the USEPA. Results from this analysis are used to update water quality reports such as the Integrated Report that’s required by Clean Water Act Section 305(b) and 303(d). For more information, please visit: Clean Water Act Section 303(d) List of Impaired Waters.
The CALM details the Core and Supplemental water quality indicators and monitoring frequencies required for ponded and flowing waters in NYS. It also establishes a process to determine whether waterbodies can support their Best Use(s). DEC applies these protocols to develop waterbody assessments that are used for permitting, compliance, and enforcement activities, developing TMDLs and other clean water plans, and funding water quality improvement projects. The CWA requires states to report the results of these assessments to USEPA every two years. This water quality reporting under Section 305(b) and 303(d) of the CWA is referred to by USEPA as Integrated Reporting (IR). With its IR submission, a state must also provide a CALM that documents the decision-making process for assessing and reporting on the quality of water in the Integrated Report. USEPA provides states with guidance for developing a CALM (Guidance for 2006 Assessment, Listing and Reporting Requirements, 2005). NYS’s methodology includes:
- a description of the processes and procedures used to assess the quality of surface waters;
- an explanation of how all existing and readily available monitoring data and information was assembled and used to determine the attainment status in each assessment unit consistent with the applicable WQS; and decision rationales to not use any existing and readily available data and information (40 CFR Section 130.7).
