From your link above....I was right about the environmentalists.
As DumpsterDiver says, this may be a way to get more exposure about this problem. These people must be squirming over this.
Dumping of Trash, Waste, Endemic in State with Flood of Illegal Immigration
Bitter Division for Sierra Club on Immigration
By Felicity Barringer, The New York Times, March 16, 2004
Immigration is creating a bitter leadership struggle in the Sierra Club, a 112-year-old organization of 750,000 members that works to bring conservation and pollution issues to public attention.
Barringer writes that the Sierra Club is struggling over "whether to advocate tough immigration restrictions as a way to control environmental damage that has been associated with rapid population growth."
U.S. Census Bureau figures show that nearly 40 percent of the U.S. population growth over the last 10 years has been a result of direct immigration; many of the immigrants have settled in California, the Sierra Club's home base.
http://usinfo.state.gov/eap/east_asia_pacific/chinese_human_smuggling/smuggling_in_the_press/environment.html