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CADDIS Volume 1

CADDIS Volume 1. Stressor Identification: Table. Water Management Programs and Stressor Identification

Table. The Role of Stressor Identification in Various Water Management Programs

Program Type/Name Purpose Role of Stressor Identification

305(b) Characterizing the Quality of the Nation's Waters

Under section 305(b) of the Clean Water Act (CWA), states and tribes are required to assess the general status of their waterbodies and identify, in general terms, known or suspected causes of water quality impairments, including biological impairments. Stressor identification procedures assist states and tribes in accurately identifying the causes of biological impairment. This is a nonregulatory, information reporting effort. A high degree of certainty in identifying the causes of impairment is not always needed for 305(b) reports.

303(d) Listings and TMDLs

Identifying Waterbodies and Wetlands that Exceed Water Quality Standards

Under section 303(d) of the CWA, states and tribes are required to prepare and submit to EPA lists of specific waterbodies that currently violate, or have the potential to violate, water quality standards, including designated uses and numeric or narrative criteria such as biocriteria. Wetlands assessment programs are also being developed and wetlands may be listed on 303(d) lists. Accurate, reliable stressor identification procedures are necessary for EPA and the states and tribes to accurately identify the cause(s) of water quality standards violations. A high degree of accuracy and reliability in the SI process is necessary and sources will need to be identified.

State/Local Watershed Management Programs

Managing water resources on a watershed basis involves examining the quality of a waterbody relative to all the stressors within its watershed. Stressors, once identified, are prioritized and controlled through a combination of voluntary and mandatory programs, possibly employing the CWA 402, 319, 404, 401, and other programs. Stressor identification procedures will help to identify the different types of stressors within a watershed that may be contributing to biological impairment. A high degree of certainty in identifying the causes of impairment is needed.

319 Nonpoint Source Control Program

The 319 program is a voluntary, advisory program under which the states develop plans for controlling the impacts of nonpoint source runoff using guidance and information about different types of nonpoint source pollution. Stressor identification procedures will help to identify the different types of nonpoint sources within a watershed that may be contributing to biological impairment. A high degree of certainty in identifying the causes of impairment is not always needed.

NPDES Permit Program

Under section 402 of the CWA, it is illegal to discharge pollutants to waters of the United States from any "point source" (a discrete conveyance) unless authorized by a National Pollutant Discharge Elimination System (NPDES) permit issued by either the states or EPA. NPDES permits are required whenever a discharge is found to be causing a violation of water quality, including biological impairment. Accurate stressor identification can be very critical in NPDES permitting cases, both for fairness and success in stressor control. The SI process can help to determine whether the discharge is the cause of biological impairment. This is especially important when site-specific modifications of state standards or national criteria are used. A high degree of accuracy and reliability in the SI process is necessary and sources will need to be identified. The SI process is not designed to allocate the amount of responsibility for an impact when multiple sources for a stressor are present.

316(b) Cooling Water Intake Program

Under section 316(b) of the CWA, any NPDES permitted discharger that also intakes cooling water must not cause an adverse environmental impact on the waterbody. To determine whether a cooling water intake structure is causing adverse environmental impacts on the waterbody, the overall health of the waterbody should be known. Where biological impairments are found, stressor identification procedures should be used to identify the different stressors causing the waterbody to be impaired, including the intake structure. A high degree of certainty is needed.

401 Water Quality Certifications

Under section 401 of the CWA, different types of federal permitting activities (such as wetlands dredge and fill permitting) require a certification that there will be no adverse impact on water quality as a result of the activity. This certification process is the 401 Water Quality Certification. Stressor identification procedures will help to identify the different types of stress an activity might place on water quality that can then be addressed through conditions in the 401 Certification.

Wetlands Permitting

Under section 404 of the CWA, the discharge of dredge and fill materials into a wetland is illegal unless authorized by a 404 Permit. The 404 Permit must receive a 401 Water Quality Certification. Stressor identification procedures may help to identify unanticipated stress from a dredge and fill activity on water quality or the biological community after the activity is underway. Stressor identification procedures will also help in pre-permitting evaluations of the potential impacts of 404 permitting by assessing different potential stressors on the wetland in advance.

Compliance and Enforcement

Whenever an enforcement action is taken by a regulatory authority, the type of pollution, the source, and other stressors that play a role in causing the violation need to be clearly identified and related to the violating source. Stressor identification procedures must be able to clearly identify the different types of pollution causing the violation with a high degree of confidence. Legal defensibility is required. Identifying the source with a high degree of confidence is also needed, though the current SI process does not provide that guidance.

Risk Assessments

Results of bioassessment studies can be used in watershed ecological risk assessments to predict risk from specific stressors and anticipate the success of management actions. Accurate stressor identification is an integral part of this process and can help ensure that management actions are properly targeted and efficient in producing the desired results.

Wetlands Assessments

States are beginning to develop wetlands assessment procedures. In the future, wetlands protection is expected to be increasingly incorporated into state water quality standards. Stressor identification procedures, as well as future tools specific to wetland investigations, are very much needed by wetlands managers. The biological assessment methods will allow resource managers to evaluate the condition of wetlands and may provide some indication of the type of stressor damaging a wetland. Once bioassessment methods are completed and incorporated into monitoring programs, wetlands may be listed on 305(b) lists as impaired due to biological impairment. The SI process should help identify stressors causing biological impairment so resource managers can better remedy the problems.

Preservation Programs

The National Estuary Program (NEP) was established in 1987 by amendments to the Clean Water Act to identify, restore, and protect nationally significant estuaries of the United States. The program focuses on improving water quality in estuaries, and on maintaining the integrity of the whole system, its chemical, physical, and biological properties as well as its economic, recreational, and aesthetic values. Stressor identification procedures should be useful to the NEP, and other preservation programs, by helping stakeholders identify causes of impairments. This information would feed into the development of a management plan.

Restoration Programs

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, was enacted in 1980 (and amended in 1986) for hazardous waste cleanup. As in enforcement and compliance programs, stressor identification procedures must be able to clearly identify the different types of pollution causing the impairment with a high degree of confidence. Legal defensibility is required. Identifying the source with a high degree of confidence is also needed, though the current SI process does not provide that guidance.

Pollution Control Effectiveness

A key component of any pollution control program or watershed management effort is the ability to ascertain (or predict) the likely effectiveness of pollution control measures or management strategies. Stressor identification procedures will help to identify the different types of pollution a control measure needs to reduce and the different types of stressors a management strategy needs to address.

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