http://www.mydesert.com/article/2010051 ... der-patrol

As Mexican officials cut the ribbon on a new wastewater treatment plant in Tijuana late last month, the U.S. Environmental Protection Agency and San Diego-area environmental watchdogs were among those on hand applauding.




The U.S. is more than an interested observer in its southern neighbor's efforts to clean up the environment along the border and even into the fringes of the Coachella Valley. It's an investor and partner.
The EPA has helped build 88 water and sewer projects along its more than 2,000-mile border with Mexico using about $550 million in Border Environment Infrastructure Funds, an offshoot of the 1993 North American Free Trade Agreement, said Douglas Liden, a water infrastructure specialist for EPA's western region.
The total cost of the work is $1.6 billion, and about half of the projects and expenditures have been on the Mexican side of the border.
The projects are in Mexican border cities experiencing explosive growth, having inadequate or no sewer systems, and usually with much smaller U.S. “sister citiesâ€