§ 130.23 - How do you develop and document your methodology for considering and evaluating all existing and readily available data and information to develop your list?

(a) Your methodology needs to explain how you will consider and evaluate all existing and readily available water quality-related data and information to determine which waterbodies you will include on Parts 1, 2, 3, and 4 of your list, and to determine how you will prioritize your schedule for establishing TMDLs for waterbodies on Part 1 of your list. You must develop a draft methodology and notify the public of the availability of the draft methodology for review and comment. You should notify directly those who submit a written request for notification. You must provide the public an opportunity to submit comments on the draft methodology for no less than 60 days. You must provide a summary of all comments received and your responses to significant comments when you provide a copy of the final methodology to EPA, as required by § 130.24 of this subpart. You must make your final methodology available to the public when you provide a copy to EPA.

(b) The methodology should explain how you will consider and evaluate the following types of data and information when you make listing decisions and develop your prioritized schedule for TMDL establishment:

(1) Physical data and information;

(2) Chemical data and information;

(3) Biological data and information;

(4) Aquatic and riparian habitat data and information; and

(5) Other data and information about waterbody impairments, including drinking water susceptibility analyses.

(c) Your methodology should, at a minimum, identify those types of data and information that you will treat as “existing and readily available” and explain how you consider the following factors in making listing decisions and in developing your prioritized schedule for TMDL establishment:

(1) Data quality and age;

(2) Degree of confidence you have in the information you use to determine whether waterbodies are impaired, including a description of the quality assurance/quality control factors you will apply to data and information; and

(3) Number and degree of exceedances of numeric or narrative criteria and periods of nonattainment of designated uses or other factors used to determine whether waterbodies are impaired.

(d) Your methodology should describe the procedures and methods you will use to collect ambient water quality information.

(e) Your methodology should, at a minimum, also include the following:

(1) A description of the selection factors you will use to include and remove waterbodies from your list;

(2) A process for resolving disagreements with other jurisdictions involving waterbodies crossed by State, Territorial, Tribal or international boundaries; and

(3) A description of the method and factors you will use to develop your prioritized schedule for establishing TMDLs.