From its inception, Public Lab has been an open community developing and utilizing civic technologies in pursuit of community-defined questions and to address community-identified environmental concerns. Organized as a global community with nonprofit offices in several U.S. states, Public Lab introduces a model of community science, which incorporates open source practices including transparent collaboration and iterative design, along with deliberative democratic governance, and practitioner empowerment through critical making supported by an open science network. Community science can enable community members to collect, interpret, and apply their own data to effect local change or participate in broader environmental research and decision-making. The authors conceptualize a tiered approach to project development, with tiers delineated by the scope of community objectives and the role of community science in achieving those objectives. Tier 1 includes performative science used to engage the public but without direct application toward community goals. Tier 2 involves community science created and conducted by members for community-relevant outcomes. Tier 3 incorporates institutional partners, building upon community data through collaborative process to achieve community goals with broader implications. Examples of Public Lab projects from each tier demonstrate the versatility of community science, and the potential opportunity for community science to facilitate public participation in environmental decision-making on multiple levels.