(The following story by Brady McCombs appeared on the Arizona Daily Star website on August 29.)
NOGALES, Ariz. — Officials continued patching up a section of a concrete wash Tuesday that was torn up by floodwaters in an effort to prevent the rupture of an exposed pipe that carries millions of gallons of raw sewage.
Workers spent the day pumping in concrete and smoothing it out on top of rocks to shore up the floor of a 116-foot stretch of wash at North Morley Avenue and East Frederick Street near downtown.
Sections of the concrete wash had been lifted and carried downstream by heavy floodwaters Friday. Sandbags surround the work area.
Dry weather overnight Monday and Tuesday gave the concrete a chance to dry.
Rain Tuesday evening caused the water in the wash to rise about 3 feet, said city spokesman Juan Pablo Guzman. Some sandbags were displaced, but no major problems were discovered.
Officials fear a heavy rain could set them back.
“This is a temporary solution only,” said Nogales Mayor Ignacio Barranza. “The city still remains on extreme alert pending potential thunderstorms that will be moving through the area over the course of the week.”
The 30-inch pipe carries up to 14 million gallons of raw sewage a day from Nogales, Sonora, to Nogales, Ariz., on its way to the Nogales International Waste Water Treatment Plant, about 8 1/2 miles north of the border in Rio Rico.
A rupture of the line could result in an environmental catastrophe, with sewage spilling into the Santa Cruz River and traveling to Tucson and beyond, Barranza said.
The forecast calls for a slight chance of rain in the next two days in the Nogales area, said Steven Reedy, a meteorologist with the National Weather Service.
The work to replace the concrete floor of the wash should protect the sewage pipe in the short term, but it doesn’t solve the much larger and costlier solution of repairing the old wash, Barranza said. To prevent further damage, officials likely will need to replace sections of the wash, he said.
The city has begun scaling back work at the damaged stretch of wash until officials decide what the long-term solution should be, who’s responsible and who’s going to pay for it, he said.
“The city of Nogales has done all it can in providing a temporary remediation of the problem,” Barranza said.
“We can’t do anymore without the assistance of the state and federal government.”
Some of that was set to begin Tuesday night with the arrival of a chief engineer and four others from the national office of the U.S. Army Corps of Engineers, he said. The mayor planned to meet with them and members of Arizona’s congressional delegation Tuesday night to discuss a final fix.
Next week, Barranza said, he’ll convene a task force to discuss the permanent fix with local, county, state and federal officials.
Government officials from Mexico are also being invited to attend the meeting, including the mayor of Nogales, Sonora, Marco Antonio Martinez Dabdoub.
“This is an international issue,” said Barranza. “His (Martinez Dabdoub) community and mine are unable to deal with the impact of certain international issues because our resources are limited.”
The Friday rains caused damage south of the border, too. Floodwaters gushed out like geysers at street level a few hundred feet east of the Dennis DeConcini port of entry in downtown Nogales, Sonora, on Ruiz Cortinas Street, said Mauro Corrales Bujanda, director of the Nogales, Sonora, Water, Sewer and Sanitation Department.
The overflow caused cracking on the street and in the walls and floor of a nearly 1,000-foot stretch of an underground wash below that comes up to the border, he said. That stretch is old and in need of repairs that are estimated at about $2.5 million, Corrales Bujanda said.
The city of Nogales, Ariz., has estimated damage to the Nogales Wash at $10 million on the U.S. side.
Union Pacific has agreed to stop running trains through Nogales for at least 14 days to avoid any further risk to the damaged area, Barranza said.
A portion of the railroad track comes within a few feet of the affected wash, and engineers fear train vibrations could cause cracks in the drying concrete or knock down walls already cracked.
The state of Arizona also stepped in. On Tuesday, acting Gov. Jan Brewer signed an emergency declaration authorizing response plans in the event of a sewer pipe break, including use of the National Guard.
Brewer took the action because Gov. Janet Napolitano is out of the country.
Brewer’s declaration authorized spending $200,000 in state funds and emergency steps, including mobilizing or activating Arizona National Guard personnel if necessary.
(The Associated Press contributed to this story.)