Credible Data Law

Iowa’s Credible Data Law requires that listing decisions be based on scientifically valid chemical, physical, or biological data collected under a scientifically accepted sampling and analysis plan, including quality control and quality assurance procedures. The Department believes that this law has been implemented in conjunction with the federal listing requirements such that all readily available and existing water quality related data and information have been used for list development.

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455B.193 Qualifications for collection of credible data.

For purposes of this part, all of the following shall apply:

1. Data is not credible data unless the data originates from studies and samples collected by the department, a professional designee of the department, or a qualified volunteer. For purposes of this subsection, "professional designee" includes governmental agencies other than the department, and a person hired by, or under contract for compensation with, the department to collect or study data.
2. All information submitted by a qualified volunteer shall be reviewed and approved or disapproved by the department. The qualified volunteer shall submit a site specific plan with data which includes information used to obtain the data, the sampling and analysis plan, and quality control and quality assurance procedures used in the monitoring process. The qualified volunteer must provide proof to the department that the water monitoring plan was followed. The department shall review all data collected by a qualified volunteer, verify the accuracy of the data collected by a qualified volunteer, and determine that all components of the water monitoring plan were followed.
3. The department shall retain all information submitted by a qualified volunteer submitting the information for a period of not less than ten years from the date of receipt by the department. All information submitted shall be a public record.
4. The department shall adopt rules establishing requirements for a person to become a qualified volunteer.

The department of natural resources shall develop a methodology for water quality assessments as used in the section 303(d) lists and assess the validity of the data.

Section History: Recent form

2000 Acts, ch 1068, §10; 2000 Acts, ch 1232, §73

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455B.194 Credible data required.

1. The department shall use credible data when doing any of the following:
   1. Developing and reviewing any water quality standard.
   2. Developing any statewide water quality inventory or other water assessment report.
   3. Determining whether any water of the state is to be placed on or removed from any section 303(d) list.
   4. Determining whether any water of the state is supporting its designated use or other classification.
   5. Determining any degradation of a water of the state under 40 C.F.R. § 131.12.
   6. Establishing a total maximum daily load for any water of the state.
2. Notwithstanding subsection 1, credible data shall not be required for any section 305(b) report and credible data shall not be required for the establishment of a designated use or other classification of a water of the state.
3. This section shall not be construed to require credible data as defined in section 455B.171, subsection 4, in order for the department to bring an enforcement action for an illegal discharge.

2000 Acts, ch 1068, §11

Footnotes

2000 Acts, ch 1068, requirements apply to section 303(d) lists created after the year 2000 list;

2000 Acts, ch 1068, §14

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455B.195 Use or analysis of credible data.

1. For any use or analysis of credible data described in section 455B.194, subsection 1, all of the following shall apply:
   1. The use of credible data shall be consistent with the requirements of the federal Water Pollution Control Act, 33 U.S.C. § 1251 et seq.
   2. The data quality for removal of water of the state from any list of impaired waters including any section 303(d) list shall be the same as the data quality for adding a water to that list.
   3. A water of the state shall not be placed on any section 303(d) list if the impairment is caused solely by violations of national pollutant discharge elimination system program permits or stormwater permits issued pursuant to section 455B.103A and the enforcement of the pollution control measures is required.
   4. A water of the state shall not be placed on any section 303(d) list if the data shows an impairment, but existing technology-based effluent limits or other required pollution control measures are adequate to achieve applicable water quality standards.
   5. If a pollutant causing an impairment is unknown, the water of the state may be placed on a section 303(d) list. However, the department shall continue to monitor the water of the state to determine the cause of impairment before a total maximum daily load is established for the water of the state and a water of the state listed with an unknown status shall retain a low priority for a total maximum daily load development until the cause of the impairment is determined unless the department, after taking into consideration the use of the water of the state and the severity of the pollutant, identifies compelling reasons as to why the water of the state should not have a low priority.
   6. When evaluating the waters of the state, the department shall develop and maintain three separate listings including a section 303(d) list, a section 305(b) report, and a listing for which further investigative monitoring is necessary. The section 305(b) report shall be a summary of all potential impairments for which credible data is not required. If credible data is not required for a section 305(b) report, the placement of a water of the state on any section 305(b) report alone is not sufficient evidence for the water of the state's placement on any section 303(d) list. When developing a section 303(d) list, the department is not required to use all data, but the department shall assemble and evaluate all existing and readily available water quality-related data and information. The department shall provide documentation to the regional administrator of the federal environmental protection agency to support the state's determination to list or not to list its waters.
   7. The department shall take into consideration any naturally occurring condition when placing or removing any water of the state on any section 303(d) list, and establishing or allocating responsibility for a total maximum daily load.
   8. Numerical standards shall have a preference over narrative standards. A narrative standard shall not constitute the basis for determining an impairment unless the department identifies specific factors as to why a numeric standard is not sufficient to assure adequate water quality.
   9. If the department has obtained credible data for a water of the state, the department may also use historical data for that particular water of the state for the purpose of determining whether any trends exist for that water of the state.
2. This section shall not be construed to require or authorize the department to perform any act listed in section 455B.194, subsection 1, not otherwise required or authorized by applicable law.

Section History: Recent form

2000 Acts, ch 1068, §12

Footnotes

2000 Acts, ch 1068, requirements apply to section 303(d) lists created after the year 2000 list;

2000 Acts, ch 1068, §14