The Western Energy Imbalance Market (EIM) Body of State Regulators (BOSR) submitted comments to the California Independent System Operator (CAISO) regarding the Regional Integration and EIM Greenhouse Gas (GHG) Compliance Initiative. The purpose of this Initiative is to address concerns that the EIM GHG market design is not capturing the impact on the atmosphere that occurs in connection with EIM transfers into the ISO to serve ISO load. This has been referred to as the secondary dispatch effect. After initially reviewing several potential design changes and stakeholder comments, the ISO focused on developing a two-pass market design to identify the amount of each non-California resource used to serve ISO load. In the third quarter of 2017, some serious and credible concerns regarding the two-pass solution were brought to the CAISO’s attention. In light of these concerns, the CAISO is re-evaluating the two-pass proposal. The BOSR submitted comments that enunciate some key principles that should be applied to any option being considered for a market design change. The BOSR will apply these principles to evaluate any proposal offered by the CAISO that impacts the EIM market design.