Arcata’s wastewater treatment plant and wildlife sanctuary combines municipal sewage treatment, wetland habitat, and public education in one landscape. Developed in stages from 1949 through 1986, the system moves sewage through sedimentation tanks, oxidation ponds, disinfecting processes, artificial marshes, and enhancement wetlands before release to Humboldt Bay. These engineered ponds and marshes both cleanse water and create habitat along the Pacific Flyway, supporting more than 327 bird species and many other animals. The site also includes the Arcata Marsh Interpretive Center, reflects decades of research tied to Cal Poly Humboldt, and has received national recognition as a model of ecological wastewater treatment.