PRESS RELEASE | Sewage Pipeline Rehabilitation Contract Award Marks Major Milestone to Address Border Wastewater Impacts

PHOENIX (July 15, 2021) – A major milestone toward infrastructure improvements to protect public health and the environment in the border region of Santa Cruz County has been reached. The United States Section of the International Boundary and Water Commission (USIBWC) on July 13, 2021 awarded a $13.8 million contract to rehabilitate a sewage pipeline in Santa Cruz County, Arizona known as the international Trunkline and International Outfall Interceptor (IOI).

The IOI pipeline conveys wastewater from the cities of Nogales and Rio Rico, Arizona and Nogales, Sonora to the Nogales International Wastewater Treatment Plant in Rio Rico. Rehabilitation of the 9.9-mile-long pipeline will address long-standing structural integrity issues associated with years of periodic releases of untreated sewage.

"This is another positive step forward towards resolving an issue that has affected residents and the environment in Nogales and Santa Cruz County for decades," said Governor Doug Ducey. "We are optimistic that this plan will upgrade critical infrastructure, result in reduced hazards from storms and flooding and bring real improvements for people and businesses in the area. This is an investment in infrastructure that will have a direct positive impact on the lives of many."

This contract is in support of the terms of the Settlement Agreement announced by ADEQ and the USIBWC on June 30, 2020, which set forth a comprehensive plan to mitigate future discharges of untreated wastewater into the Nogales Wash and Santa Cruz River in Nogales, Arizona. With $38,790,000 in federal, state and local non-profit resources, the plan brings much-needed infrastructure improvements to Santa Cruz County.

The IOI rehabilitation work will be divided into five phases and the current contract award is for the first three phases, which includes rehabilitation of 56 manholes and over 5 miles of the sewage pipeline at key locations vulnerable to damage from stormwater and debris. Construction is expected to be completed in 2023.

“We appreciate the work that went into getting this contract awarded and look forward to the start of the construction work for this critical infrastructure necessary to improve environmental conditions in the region,” said ADEQ Director Misael Cabrera, P.E.


  • Updates on the Nogales IOI | View >
  • USIBWC July 13, 2021 News Release | View >


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