The California Air Resources Board this week issued a letter to Volkswagen Group asking it to provide more details on the zero-emissions vehicle (ZEV) infrastructure it plans to implement across the United States between 2018 and 2020.

CARB’s concern is over VW’s $800 million commitment to California to build out ZEV-related investments over 10 years as part of a multi-billion dollar settlement with it and the U.S. EPA over diesel emissions cheating.

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The CARB letter dated May 24 came almost a month after CARB had said to expect it, and asked for a supplementary document describing the long-term vision for the ZEV plan – dubbed “Electrify America” by VW.

The environmental watchdog is looking for those at VW’s ZEV Investment Plan (ZIP) arm to provide it with detailed information on its ZEV investments and an estimated schedule for implementing each investment. It says the info should consist of Electrify America’s long-term goals for ZEV investment in California, how developing infrastructure in major metropolitan areas first and extending to rural regions will progress and how ZIP spending will affect disadvantaged/underserved communities.

In addition, the document also asks for more details on ZIP’s potential future investment in hydrogen fuel cell infrastructure. CARB wants ZIP to address potential investment in hydrogen fueling stations over the 10-year period, heavy-duty hydrogen projects such as freight fleet or shuttle programs and the potential for gas-station like plazas that include both EV charging and hydrogen refueling stations. CARB is also looking for VW to provide it with a description of Electrify America’s structure and proposed business model and a commitment from the automaker to keep it consistently updated with its ZEV investments and other projects.

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“The California Air Resources Board (CARB) is eager to move forward with the first phase of investments in zero-emission vehicle (ZEV) infrastructure, education, and public access agreed to in the 2.0 liter Partial Consent Decree (Consent Decree),” the document reads.

The “Electrify America” spending plan is apart of VW’s “dieselgate” scandal finalized last year with the California Air Resources Board (CARB) and the U.S. Environmental Protection Agency (EPA). Through the Electrify America subsidiary, VW will spend $500 million in four consecutive 30-month periods for 10 years propping up EV charging stations all over the U.S. It will also spend $44 million implementing “Green City initiatives” such as EV taxi and delivery fleets and about $55 million promoting public awareness of alternative energy vehicles.