(a) For oil and natural gas wells wellheads and components subject to Subpart 203-2 of this Part, each well site shall be inspected by OGI, Method 21 or similar approved alternative method:

1. (1) semiannually; or
2. (2) one time over 24 months if using an approved alternative method which offers continuous monitoring.

(b) For natural gas gathering and boosting components subject to Subpart 203-3 of this Part, each gathering and boosting station shall be inspected by OGI, Method 21 or similar approved alternative method:

1. (1) quarterly; or
2. (2) one time over 24 months if using an approved alternative method which offers continuous monitoring.

(c) Natural gas transmission compressor station components subject to Subpart 203-4 of this Part shall be inspected by OGI, Method 21 or similar approved alternative method:

1. (1) bimonthly, at least 45 days apart; or
2. (2) one time over 12 months if using an approved alternative method which offers continuous monitoring.

(d) Storage facility components subject to Subpart 203-5 of this Part shall be inspected by OGI, Method 21 or similar approved alternative method:

1. (1) bimonthly, at least 45 days apart; or
2. (2) one time over 12 months if using an approved alternative method which offers continuous monitoring.

(e) City gate components subject to Subpart 203-6 of this Part shall be inspected by OGI, Method 21 or similar approved alternative method:

1. (1) quarterly; or
2. (2) One time over 12 months if using an approved alternative method which offers continuous monitoring.