A Federation colony where Beverly Crusher lived as a girl with her grandmother, who treated survivors of a disaster with herbs and roots when medicines ran out.
Arvada III is a colony world mentioned in the Next Generation episode The Arsenal of Freedom.
Trapped in a cavern on Minos with a badly injured Beverly Crusher, Picard has to treat her under her own direction. When he asks how she knows which roots can be used as medicine, she tells him about Arvada III.
She was there as a child with her grandmother when a catastrophe struck the colony. Once the medical supplies were exhausted, her grandmother, though not a doctor, kept people alive with local plants. Crusher learned from her, and Picard remarks that he had never known this about her past.