Ohai Wastewater Treatment Plant, Wallace Takitimu Community, Southland

Ohai wastewater treatment plant is located in the Wallace Takitimu Community within the Southland District of New Zealand. This small-scale facility serves a population of 307 residents, reflecting the rural character of the area. The plant is situated inland, more than 10 km from the coast, and treats wastewater from the local community. The plant provides secondary treatment, which is the standard level required under New Zealand's National Environmental Standards for Sources of Human Drinking Water and the Resource Management Act. For a small agglomeration of this size, secondary treatment ensures effective removal of organic matter and solids, meeting regulatory expectations for inland discharge. The treated effluent is discharged into local waterways that ultimately drain into the Southland region's river systems, which flow toward the southern coast of New Zealand. These waters support diverse aquatic life and are important for local ecosystems and recreational activities. The plant's operation contributes to protecting downstream water quality in this ecologically sensitive area.

The plant discharges into local streams that are part of the Southland region's drainage network, which flows into the Foveaux Strait or the Tasman Sea. This watershed supports native fish species and wetland habitats. The inland location reduces direct marine impact, but careful management is needed to protect freshwater ecosystems from nutrient enrichment.