Comment Sought On Draft Water Quality Assessment And Impaired Waters List
RALEIGH – The N.C. Division of Water Quality is seeking comment on its draft updated assessment of waterbodies in North Carolina, including a list of impaired waters and strategies for water quality improvement.
The 2004 Water Quality Assessment and Impaired Waters List is available on the DWQ’s Web site at: http://h2o.enr.state.nc.us/tmdl/ or by writing: Robin Markham, Division of Water Quality Planning, NC DENR, 1617 Mail Service Center, Raleigh, NC 27699-1617, or ro***********@nc****.net, or calling (919) 733-5083, ext. 558. Copies are also available at the division’s regional offices and central office in downtown Raleigh.
The document, which is updated every two years, is a comprehensive accounting of how well surface waters, groundwaters, and wetlands support their designated uses, such as swimming, aquatic life support and water supply. The report also lists which waters do not support their designated uses and the likely causes of the impairment.
In North Carolina, the number one rated cause for streams to be rated as impaired is poor biological integrity; more than 1600 miles of streams are impaired by this standard. Poor biological integrity means that the stream does not have an appropriate number and/or variety of benthic macroinvertebrates, aquatic bugs that are large enough to be seen with the naked eye.
These animals, primarily aquatic insect larvae, are sensitive to subtle changes in water quality and can be indicators of a wide range of environmental stresses. These stresses fall into two broad classes: 1) chemical or physical pollutants, such as toxic chemicals or oxygen-consuming wastes; and 2) habitat degradation such as loss of riffles and pools due to sedimentation or scour due to increased force of waters from stormwater flow or wetlands loss.
“We have enhanced our ability to identify the sources and relative effects of such stresses and completed more than 20 studies of specific streams over the last two years,” said Michelle Woolfolk, environmental supervisor in DWQ’s planning branch and one of the authors of the report. “Our ability to assess layers of plausible, potential causes, and evaluate multiple lines of evidence to determine to what degree a possible stressor is actually a contributor to impairment is constantly improving.”
Other notable areas of the 2004 report include:
· The number one rated source of impairment is urban runoff and storm sewers. Stormwater runoff carries natural and human-made pollutants into waterbodies from a variety of sources and may include sediment, nutrients, bacteria, oil and grease, trace metals, toxic and synthetic chemicals. The quantity and force of stormwater can also cause changes in aquatic habitat such as scouring, stream bank erosion and excessive instream sedimentation.
· To reduce multiple counts of the same stream segment, those that have multiple source types of impairment are listed once under a priority category rather than presented in several categories. All known sources of impairment are included in the single listing. For example, if a stream segment is impaired because of its lack of biological integrity, excessive nutrients and a chemical pollutant; under the 2004 design, the stream and all its impairment sources will be listed under one priority category rather than being listed in three as in previous years.
· Use support ratings for the Broad, Neuse, and Yadkin-Pee Dee river basins have been updated since the 2002 report. Use support for each of these basins is contained in the basinwide management plans approved by the Environmental Management Commission before November 2003. Generally, use support ratings for each of the state’s 17 river basins are evaluated every five years on a rotating basis as the basinwide management plans are revised.
· Work has begun on an aggressive program to define and characterize Piedmont and Mountain area groundwater hydrology in cooperation with the U.S. Geological Survey. Knowledge of the quality and availability of the shallow aquifer system, its vulnerability to contamination, and its relationship to the recharge of surface water resources is necessary in order to provide appropriate levels of protection for present and future use. Four research stations were completed in 2003 and reports from these sites will be available this year.
The report also summarizes sample collection and reporting methodology, state classifications and standards, monitoring, assessment, and other state programs that contribute to the report’s findings.
Comments on the draft report and impaired waters list should be submitted in writing no later than May 31 to Robin Markham at the above address. The Division of Water Quality will submit the final list to the U.S. Environmental Protection Agency by June 30.
Comment Sought On Draft Water Quality Assessment And Impaired Waters List
RALEIGH – The N.C. Division of Water Quality is seeking comment on its draft updated assessment of waterbodies in North Carolina, including a list of impaired waters and strategies for water quality improvement.
The 2004 Water Quality Assessment and Impaired Waters List is available on the DWQ’s Web site at: http://h2o.enr.state.nc.us/tmdl/ or by writing: Robin Markham, Division of Water Quality Planning, NC DENR, 1617 Mail Service Center, Raleigh, NC 27699-1617, or ro***********@nc****.net, or calling (919) 733-5083, ext. 558. Copies are also available at the division’s regional offices and central office in downtown Raleigh.
The document, which is updated every two years, is a comprehensive accounting of how well surface waters, groundwaters, and wetlands support their designated uses, such as swimming, aquatic life support and water supply. The report also lists which waters do not support their designated uses and the likely causes of the impairment.
In North Carolina, the number one rated cause for streams to be rated as impaired is poor biological integrity; more than 1600 miles of streams are impaired by this standard. Poor biological integrity means that the stream does not have an appropriate number and/or variety of benthic macroinvertebrates, aquatic bugs that are large enough to be seen with the naked eye.
These animals, primarily aquatic insect larvae, are sensitive to subtle changes in water quality and can be indicators of a wide range of environmental stresses. These stresses fall into two broad classes: 1) chemical or physical pollutants, such as toxic chemicals or oxygen-consuming wastes; and 2) habitat degradation such as loss of riffles and pools due to sedimentation or scour due to increased force of waters from stormwater flow or wetlands loss.
“We have enhanced our ability to identify the sources and relative effects of such stresses and completed more than 20 studies of specific streams over the last two years,” said Michelle Woolfolk, environmental supervisor in DWQ’s planning branch and one of the authors of the report. “Our ability to assess layers of plausible, potential causes, and evaluate multiple lines of evidence to determine to what degree a possible stressor is actually a contributor to impairment is constantly improving.”
Other notable areas of the 2004 report include:
· The number one rated source of impairment is urban runoff and storm sewers. Stormwater runoff carries natural and human-made pollutants into waterbodies from a variety of sources and may include sediment, nutrients, bacteria, oil and grease, trace metals, toxic and synthetic chemicals. The quantity and force of stormwater can also cause changes in aquatic habitat such as scouring, stream bank erosion and excessive instream sedimentation.
· To reduce multiple counts of the same stream segment, those that have multiple source types of impairment are listed once under a priority category rather than presented in several categories. All known sources of impairment are included in the single listing. For example, if a stream segment is impaired because of its lack of biological integrity, excessive nutrients and a chemical pollutant; under the 2004 design, the stream and all its impairment sources will be listed under one priority category rather than being listed in three as in previous years.
· Use support ratings for the Broad, Neuse, and Yadkin-Pee Dee river basins have been updated since the 2002 report. Use support for each of these basins is contained in the basinwide management plans approved by the Environmental Management Commission before November 2003. Generally, use support ratings for each of the state’s 17 river basins are evaluated every five years on a rotating basis as the basinwide management plans are revised.
· Work has begun on an aggressive program to define and characterize Piedmont and Mountain area groundwater hydrology in cooperation with the U.S. Geological Survey. Knowledge of the quality and availability of the shallow aquifer system, its vulnerability to contamination, and its relationship to the recharge of surface water resources is necessary in order to provide appropriate levels of protection for present and future use. Four research stations were completed in 2003 and reports from these sites will be available this year.
The report also summarizes sample collection and reporting methodology, state classifications and standards, monitoring, assessment, and other state programs that contribute to the report’s findings.
Comments on the draft report and impaired waters list should be submitted in writing no later than May 31 to Robin Markham at the above address. The Division of Water Quality will submit the final list to the U.S. Environmental Protection Agency by June 30.