Overview
IBWC Nogales International WTP in Calabasas, Arizona, serves approximately 388,000 people. The plant is part of the International Boundary and Water Commission's infrastructure along the US-Mexico border.
The IBWC Nogales International WTP is a major wastewater treatment facility located in Calabasas, Santa Cruz County, Arizona. Operated under the International Boundary and Water Commission, it serves a population of around 388,120, making it a large agglomeration in the region. The plant's location near the US-Mexico border underscores its role in cross-border environmental management. As a large-scale facility, the plant is expected to meet secondary treatment standards under the US Clean Water Act, administered through the EPA's National Pollutant Discharge Elimination System (NPDES) permit program. Plants of this size typically employ advanced biological treatment to comply with stringent discharge limits. The treated effluent from the plant likely discharges into the Santa Cruz River or its tributaries, which flow south into Mexico and eventually contribute to the Gulf of California. The river supports riparian habitats in an arid region, making water quality management critical for local ecosystems and downstream communities.
Environmental context
The plant's discharge enters the Santa Cruz River watershed, which flows through southern Arizona into Sonora, Mexico, and ultimately drains into the Gulf of California. This arid region relies on the river for groundwater recharge and riparian habitat. The plant's operations help protect the river's water quality, supporting diverse aquatic life and migratory birds in a water-scarce environment.
Frequently asked questions
The plant is located on Pendleton Drive in Calabasas, Santa Cruz County, Arizona, near the US-Mexico border.
The plant serves approximately 388,120 people, classifying it as a large agglomeration under US and international standards.
The treated effluent is likely discharged into the Santa Cruz River or its tributaries, which flow south into Mexico and eventually reach the Gulf of California.
As a US facility, the plant operates under the Clean Water Act and is subject to EPA NPDES permits, which set discharge limits to protect water quality.
Plants of this scale typically employ secondary or advanced treatment, including biological processes and disinfection, to meet NPDES permit requirements.
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