Environmental Justice Mapping and Data Collection Act of 2021 This bill establishes an interagency Environmental Justice Mapping Committee that must create a tool to identify environmental justice communities. Environmental justice communities are communities with significant representation of communities of color, low-income communities, or tribal and indigenous communities that experience, or are at risk of experiencing, higher or more adverse human health or environmental effects, as compared to other communities. The Environmental Protection Agency (EPA) must establish an environmental justice data repository to maintain the data collected by the committee. The EPA must make the repository available to regional, state, local, and tribal governments.