Author

Mark Olalde, ProPublica
Mark Olalde is a reporter covering the environment in the Southwest. Before joining ProPublica, he wrote for The Desert Sun, The Arizona Republic and the Center for Public Integrity. His investigations, which have taken him to numerous countries, have also been published in the Los Angeles Times, High Country News, USA Today and international outlets. Olalde's coverage of hidden cleanup liabilities in California's oilfields earned him the 2020 Stokes Award. His work on South Africa's abandoned mines prompted a parliamentary investigation and saw him recognized in 2017 as the country's top print reporter covering the environment.
The Cold War legacy lurking in U.S. groundwater
By: Alex Mierjeski, ProPublica, Mollie Simon and Mark Olalde, ProPublica - December 29, 2022
In America’s rush to build the nuclear arsenal that won the Cold War, safety was sacrificed for speed. Uranium mills that helped fuel the weapons also dumped radioactive and toxic waste into rivers like the Cheyenne in South Dakota and the Animas in Colorado. Thousands of sheep turned blue and died after foraging on land tainted by processing […]
The Southwest’s drought and fires are a window to our climate change future
By: Mark Olalde, ProPublica - May 20, 2022
The concentration of carbon dioxide in Earth’s atmosphere has reached its highest level in recorded human history. Again. In April, the level of CO2 was 27% higher than it was 50 years ago, according to the latest data from the National Oceanic and Atmospheric Administration and the Scripps Institution of Oceanography. (Methane, a gas with […]