Excessive bacteria found after US Mexico sewage pipe break

A wash in southern Arizona where an international sewage pipeline has spilled untreated wastewater has tested positive for excessive levels of E. coli. (Photo by NIAID/Flickr, CC BY 2.0)

A wash in southern Arizona where an international sewage pipeline has spilled untreated wastewater has tested positive for excessive levels of E. coli, officials said Thursday.

Testing is ongoing and the public should stay out of Nogales Wash and Santa Cruz River, Santa Cruz County said in a news release. The Arizona Department of Environmental Quality performed the tests.

“Until there is more information about the extent of the situation, it is recommended not using water from the Santa Cruz River to water food crops or gardens. Livestock should not be in the river or drinking from it,” county health services director Jeff Terrell said in the news release.

Arizona Gov. Doug Ducey on Thursday declared a state of emergency, saying he was allocating $200,000 from the general fund to help with repair management as the state’s congressional delegation put pressure on an international water commission to address the issue.

The International Boundary and Water Commission says it has not verified that there’s a leak and that the wastewater plant that the pipe leads to is receiving normal flows.

Authorities in Santa Cruz County say they noticed a break in a pipeline during an inspection on Tuesday. They say the pipe, also known as the International Outfall Interceptor, has a breach in a sparsely populated area north of the international border. Authorities believe the break happened because of excessive rainwater that put too much pressure on the pipe.

“This week’s severe breach to the International Outfall Interceptor (IOI) sewage pipeline along the U.S.-Mexico border is just the latest in a long history of unacceptable breakages to this deteriorating pipeline,” Sen. John McCain said in a statement Wednesday.

The pipe carries 10 to 14 million gallons of untreated wastewater from Nogales, Mexico, to a treatment centre in Rio Rico, Arizona, operated by the water commission. The water is then released into the Santa Cruz river. The pipe runs for nearly 9 miles (14 kilometres) underground.

The city of Nogales said it would cost about $5 million to repair the pipe, according to a state of emergency it issued Wednesday.

The IOI has been a point of contention in southern Arizona for years and is embroiled in a lawsuit over who has the financial burden to make repairs on the 45-year-old pipe.

“USIBWC does not own the IOI and is not responsible for its operation or maintenance,” spokeswoman Lori Kuczmanski said.

A federal judge overseeing the lawsuit issued a report in April finding that the water commission owns the pipe. The commission is objecting to the recommendation. A final ruling is pending.

“The IBWC, which is tasked with the management of international water and boundary treaties, should be responsible for managing the infrastructure it relies on so heavily for international gain,” McCain said.

The Nogales, Arizona, area is fraught with issues arising from rainwater. Water runs north into the U.S. from Mexico because of the area’s topography. But the Mexican side of the border lacks the infrastructure to prevent inundations and debris from hitting the American side when it rains heavily there.

In 2014, a flood that started on the Mexican side knocked over part of the steel border international fence that’s 18 feet to 24 feet tall, costing about $730,000 in repairs. It sent tree trunks and other debris into Arizona, destroying mobile homes and businesses.

Terrell said during a news conference that the trick to making repairs to the broken pipe will be to beat another set of rainstorms that are supposed to hit the area this weekend.