For decades, California has taken the lead in setting standards for water reuse. Other parts of the U.S. that have struggled with water stress or scarcity have used the state’s Title 22 regulations as a benchmark for their own guidelines or need-based treatment designs. On Oct. 1, 2024, California’s new Title 22 regulations took effect, which include guidance on direct potable reuse (DPR). Within the state, continued treatment investigation and investment are expected. Even outside California, water utilities, regulators, manufacturers, and design engineers should understand these new guidelines, the processes, and the technologies they cover in order to prepare themselves for implementation.