https://phys.org/news/2018-05-oil-gas-wastewater-road-health.html

The spreading of O&G wastewater on roads is permitted in at least 13 U.S. states, with significant spreading activity occurring in Ohio and Pennsylvania. The team studied O&G wastewater spread on roads and found them to contain salt, radioactivity and organic contaminant concentrations above their respective drinking water standards. These substances can be harmful to humans and aquatic life. In lab simulations, nearly all of the metals from these wastewaters leached out after simulated rain events, but metals such as radium—which is radioactive and a known carcinogen—and lead were partially retained on roadways. The researchers speculate that the radium that did leach could end up in nearby bodies of water. The group proposes that establishing wastewater standards and treatment guidelines for O&G wastewaters spread on roads could help reduce the potential environmental impacts of this practice.

                                                            
                                    
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T. L. Tasker et al. Environmental and Human Health Impacts of Spreading Oil and Gas Wastewater on Roads, Environmental Science & Technology (2018). DOI: 10.1021/acs.est.8b00716