If a state chooses to implement a state or regional ECO plan, it is the state's responsibility to design and implement in good faith the regional plan as well as to include it in the state regulation and SIP submittal. If a state chooses to implement an employer based program, it is the state's responsibility to receive and review employer plans as required by state regulation. Employers under an employer based program are responsible for submitting ECO compliance plans to the state as required by the state regulation.
Employers are also responsible for making a good faith effort to implement their compliance plans.
An employer's responsibilities under a state or regional plan will be determined by each state. Individual SIP revisions are required from each state subject to the ECO requirement even if programs are coordinated with other states. This ECO option allows states or regions within states to assume the responsibility from employers for meeting the ECO requirements. State or regional ECO plans can be developed so that employers are relieved of the need to submit individual plans and so that employers would not be subject to civil suits. A state or regional plan would take the place of individual employer plans and would need to achieve the same level of trip reductions as required under an employer based plan.