MNWD WWTP 3 A, Mission Viejo

Overview

MNWD WWTP 3 A serves Mission Viejo, California, treating wastewater for approximately 63,100 residents. The plant operates under the US Clean Water Act and discharges into the local watershed.

MNWD WWTP 3 A is a municipal wastewater treatment plant located in Mission Viejo, Orange County, California. It serves a population of approximately 63,100 people, making it a medium-sized facility within the region's wastewater infrastructure. The plant is situated along Oso Creek Trail and is part of the broader Moulton Niguel Water District system. As a US-based facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the California State Water Resources Control Board. For a plant serving over 60,000 people, secondary treatment is typically required, with potential additional nutrient removal to protect sensitive water bodies. The designed capacity is reported at 1.00 (likely million gallons per day or similar unit), indicating the plant's treatment capability. The plant's treated effluent is discharged into Oso Creek, a tributary of San Juan Creek, which flows into the Pacific Ocean at Dana Point. This coastal discharge location places the plant within 50 km of the coast, necessitating careful management to protect marine ecosystems. The watershed supports diverse aquatic life and is an important corridor for migratory species.

Environmental context

The plant discharges into Oso Creek, which flows into San Juan Creek and ultimately reaches the Pacific Ocean at Dana Point. This coastal watershed supports sensitive marine habitats, including estuaries and nearshore environments that provide nursery grounds for fish and habitat for shorebirds. Nutrient loading from wastewater can contribute to algal blooms and hypoxia, so treatment standards are designed to minimize ecological impact.

Frequently asked questions

MNWD WWTP 3 A is located along Oso Creek Trail in Mission Viejo, Orange County, California, United States.

The plant serves approximately 63,100 residents in the Mission Viejo area.

Treated effluent from the plant is discharged into Oso Creek, which flows into San Juan Creek and then into the Pacific Ocean at Dana Point.

As a US facility, the plant operates under the Clean Water Act and is regulated by the California State Water Resources Control Board through an NPDES permit.

Plants of this scale in California typically provide secondary treatment as a minimum, with advanced treatment or nutrient removal often required to protect sensitive coastal waters.