(a) Except as provided in subdivision (b) of this section, a line marker must be placed and maintained as close as practical over each buried main and transmission line:

1. (1) at each crossing of a public road, railroad and navigable waterway; and
2. (2) wherever else necessary to identify the location of the main or transmission line to reduce the possibility of damage or interference.

(d) The following must be written legibly on a background of sharply contrasting color on each line marker other than at navigable waterways:

1. (1) the word “Warning,” “Caution” or “Danger” followed by the words “Gas” (or name of gas transported) “Pipeline,” all of which, except for markers in heavily developed urban areas, must be in letters at least one inch high with one-quarter inch stroke; and
2. (2) the name of the operator and a telephone number (including area code) where the operator can be reached at all times.

(e) Each line marker at a navigable waterway shall have the following characteristics:

1. (1) a sign, rectangular in shape, with a narrow strip along each edge colored international orange and the area between lettering on the sign and boundary strips colored white;
2. (2) written on the sign in block style, black letters the word “Warning,” “Caution” or “Danger” followed by the words “Do not anchor or dredge” and the words “Gas Pipeline Crossing”;
3. (3) the name of the operator and the telephone number (including area code) where the operator can be reached at all times; and
4. (4) in overcast daylight, the sign is visible and the writing required by paragraph (2) of this subdivision is legible, from approaching or passing vessels that may damage or interfere with the pipeline.