First rehabilitation phase of binational sewage pipeline finished as monsoon rains persist

The first rehabilitation phase of the aging binational sewage pipeline that runs from Mexico into Arizona has completed as monsoon flood waters and concerns over the pipe continue to rise in the cross-border community.

The pipeline carries an average of 13 to 17 millions of gallons of raw sewage daily from Nogales, Sonora, to a water treatment plant in Rio Rico, Arizona, before the water is released into the Santa Cruz river. The deteriorating pipe, also known as the International Outfall Interceptor, runs underground for nearly 9 miles.

The deteriorating condition of the 50-year-old sewer has led to ruptures and leaks, causing severe groundwater contamination, raising environmental concerns and exposing nearby communities to “extraordinary” public health risk.

The area near Nogales, Arizona, has long been inundated with problems from rainfall, given that the topography makes water run north from Mexico into the U.S.

Concerns about leaks in the pipeline are renewed every monsoon season when sections of the pipe near, inside and across the Nogales Wash are vulnerable to increased stormwater pressure.

Rehabilitation groundbreaking: Rehabilitation of cross-border sewage pipeline begins in Nogales, Arizona

“It’s getting to emergency levels,” said Jaime Chamberlain, chair of the Greater Nogales Santa Cruz County Port Authority. “We've never had this rush of water in such a short time.”

Chamberlain spoke Wednesday during a port authority board of directors meeting where updates on the status of the rehabilitation of the pipe were shared.

The entire rehabilitation project, which consists of five phases, is about 33% complete, officials announced Wednesday. The first phase of the project was completed Aug. 19 near Rio Rico.

As part of the first rehabilitation phase, officials cleaned out a portion of the pipeline and accumulated a pile of hefty rocks, old pipes, a tape measure and a shattered rusty manhole cover that were clogging the pipe.

Phase three is estimated to begin in mid-September and phase two is projected to start in January 2023. Phases 1-3 included rehabilitation on 5.3 miles of the pipe and 56 manholes, officials said.

Completion of phases four and five is estimated to be summer 2024, officials said.

In February, groundbreaking on the first phase of rehabilitation of the pipeline began. The rehabilitation, which is expected to add another 50 years of life to the pipeline, is expected to cost about $50 million.

Many have said that the rehabilitation is long overdue as critics classify the project as a short-term solution to a larger ongoing issue.

Longstanding issues

On Aug. 12, officials with the Arizona Department of Environmental Quality (ADEQ) and Santa Cruz County cautioned residents against contact with water in the Nogales Wash and Potrero Creek because of sewer overflows from Mexico into the U.S. caused by the heavy monsoon rains.

In July, Sens. Kyrsten Sinema, D-Ariz., and Mark Kelly, D-Ariz., alongside Reps. Raúl Grijalva, D-Ariz, and Ann Kirkpatrick, D-Ariz, introduced bicameral legislation that would transfer ownership, operations and maintenance of the cross-border pipeline to the U.S.-section of the International Boundary and Water Commission.

Pipeline funding: Sen. Sinema to seek extra federal funding for repairs of binational sewage pipeline

“For too long, the City of Nogales has received little to no support from Washington on this issue,” Kelly said at the time in a written statement. “Our bill will finally provide the City of Nogales with a permanent solution, which protects public health and improves infrastructure in Arizona’s border communities.”

Monsoon rains this year have been particularly treacherous for residents of the cross-border communities. Recently, heavy rains have led to flash floods that fervently race through the streets of Nogales, Sonora, toppling cars and washing people away.

On Aug. 13, two girls and one woman died and 11 others were rescued during flash floods resulting from heavy rains in Nogales, Sonora. Similar monsoon floods in the past have been known to wash bodies across the border from Mexico into Arizona.

“It’s been really devastating,” Chamberlain said in regard to the heavy monsoon rains and flooding in Nogales, Arizona, during the meeting Wednesday. "We have some major issues in town and as far as the flooding is concerned and some of our streets, we're almost to the point of emergency.”

In 2017, the international pipeline leaked thousands of gallons of raw sewage from Mexico into the Nogales Wash in southern Arizona. Strong monsoon currents running in the Nogales Wash caused a portion of the exposed pipeline to rupture just north of Nogales’ city limits.

The 2017 rupture prompted Arizona Gov. Doug Ducey to declare a state of emergency following the discovery of excessive levels of E. coli in water sources near the wash. Ducey subsequently activated the National Guard to help authorities repair the pipeline.

Contact the reporter at jcastaneda1@arizonarepublic.com or connect with him on Twitter @joseicastaneda.

This article originally appeared on Arizona Republic: Rehabilitation of cross-border pipeline underway as flooding continues