The importance of the Colorado River to the Southwest U.S. and to Mexico has only grown greater as demand for continental and worldwide water resources does too. It's also just one of many shared bi-national natural resources – the air polluted by trucks of both nations is another – that now come under greater scrutiny in the border zone. The latest manifestation of these twin trends is the All American Canal concrete lining project.
The U.S. Bureau of Reclamation proposes to line 23 miles (37 km.) of this 82-mile (132-km.), 70-year-old canal in order to prevent the seepage of some (80 million cubic meters) of water a year in a sandy area that follows the U.S.-Mexico border. But, says Baja California Gov. Eugenio Elorduy Walther, that seepage is crucial to 4,600 acres of wetlands on the Mexican side, home to more than 100 species of birds, including 12 considered threatened or endangered.
Bids on the project are being evaluated this spring, with a notice to proceed expected in May and completion as soon as 2008.
Tire Debate Goes 'Round
Waste tire piles have in the past been a serious environmental concern along the U.S.-Mexico border, with some piles numbering in the millions. An EPA plan called Border 2012 is addressing the scrap tire pile issue, headed in part by the Rubber Manufacturers Association (RMA).
In an unpublished 2004 interview with Site Selection, Michael Blumenthal, RMA senior technical director, said companies such as Mexico’s Cemex and IPSCO were leading the way in using some tires for kiln fuel and for iron ore recovery. "The use of tires as a charge material in the steelmaking process is relatively new," he said of the electric arc furnace method, which enables 80 percent of the tire to be recycled, as opposed to 12 percent in the cement kiln scenario. Blumenthal said there are 43 different cement locations, with 60 kilns, using tire-derived fuel in the U.S. He also noted that "the economics get mushy" once scrap tires have to be shipped more than 150 miles [241 km.].
"Tires are a trusted fuel, they know what to expect," he said, though cement end users' upper limit on feedstock percentage would be around 25 percent. He also sounded a note of caution that turned out to be well-founded in light of the surging house construction market and catastrophic weather in the Gulf of Mexico: "If we see a tremendous spike in demand for cement," he said, "we might just see a corresponding decrease in the use of alternative fuels in manufacturing."
An EPA plan called 