Surface Water Quality Assessments 305(b) and 303(d)
The Surface Water Quality Assessment Program produces two surface water quality documents every two years, the "305(b) Report" and the "303(d) List". As the two documents use the same data, the 305(b) Report and 303(d) List were combined into one Integrated Report starting in 2002. The Integrated Report describes the quality of New Hampshire’s surface waters and an analysis of the extent to which all such waters provide for the protection and propagation of a balanced population of shellfish, fish, and wildlife, and allow recreational activities in and on the water.
The Federal Water Pollution Control Act [PL92-500, commonly called the Clean Water Act (CWA)], as last reauthorized by the Water Quality Act of 1987, requires each state to submit two surface water quality documents to the US Environmental Protection Agency (EPA) every two years. Section 305(b) of the CWA requires submittal of a report (commonly called the "305(b) Report"), that describes the quality of its surface waters and an analysis of the extent to which all such waters provide for the protection and propagation of a balanced population of shellfish, fish, and wildlife, and allow recreational activities in and on the water.
The second document is typically called the "303(d) List," which is so named because it is a requirement of Section 303(d) of the CWA. The 303(d) List includes surface waters that are:
- Impaired or threatened by a pollutant or pollutant(s).
- Not expected to meet water quality standards within a reasonable time even after application of best available technology standards for point sources or best management practices for nonpoint sources.
- Require development and implementation of a comprehensive water quality study (a Total Maximum Daily Load (TMDL) study) which is designed to meet water quality standards.
Prior to 2002, New Hampshire, along with many other states, submitted separate 305(b) Reports and 303(d) Lists. To some, this was confusing as it was unclear how waters listed in the two documents were related. In an effort to eliminate this confusion and to simplify reporting for the public as well as regulatory agencies, the 305(b) Report and 303(d) List were combined into one Integrated Report with five categories:
- Attaining all designated uses and no use is threatened.
- Attaining some of the designated uses; no use is threatened; and insufficient or no data and information is available to determine if the remaining uses are attained or threatened (i.e., more data is needed to assess some of the uses).
- Insufficient or no data and information are available to determine if any designated use is attained, impaired, or threatened (i.e., more monitoring is needed to assess any use).
- Impaired or threatened for one or more designated uses but does not require development of a TMDL because;
- a TMDL has been completed, or
- other pollution control requirements are reasonably expected to result in attainment of the water quality standard in the near future, or
- the impairment is not caused by a pollutant.
- Impaired or threatened for one or more designated uses by a pollutant(s), and requires a TMDL (this is the 303(d) List).
The Consolidated Assessment and Listing Methodology (or CALM) describes, in detail, the process used to make surface water quality attainment decisions for 305(b) reporting and 303(d) listing purposes. The term "listing" refers to the process of placing (or listing) a water on the Section 303(d) List of impaired waters. The CALM also includes descriptions and definitions of the many terms used in the presentation of assessment results; consequently all are encouraged to review the CALM prior to reviewing the assessments as it will help one to better understand and interpret assessment results.
It is important to understand that assessment methodologies are dynamic and change as new information and assessment techniques become available. Such changes can also impact monitoring strategies designed to determine if waterbodies are attaining water quality standards. Periodic updates of the methodology will hopefully result in even more accurate and reliable assessments and, therefore, better management of water resources in the future.