on and offsite. Exposure to fluids involved in fluid spills (flowback water, fracking fluid, produced waters) also exposes nearby workers to any and all compounds, toxic or not, contained within those fluids. Between 2009 and 2014, more than 21,000 individual spills were reported across the U.S., involving a total of 175 million gallons of wastewater. Although using properly designed storage equipment at well sites protects against accidents such as spills, extreme weather conditions expose wells and make them vulnerable to spills regardless, exposing workers to additives, blended hydraulic fracturing fluids, flow back fluids and produced water, along with the hazardous materials therein. Explosions According to the latest information available (collected in 2013), the Oil and Gas Industry has the highest number of fires and explosions of any private industry in the U.S. One of the greatest hazards faced by workers is during the pipeline repair process, which makes them vulnerable to flammable gas explosions. There currently exist very few training protocols for workers under these circumstances. Radioactive materials exposure According to the EPA, unconventional oil and gas development is a source of technologically enhanced naturally occurring radioactive materials (TENORM). The processes used in drilling, pumping water, and retrieving flow back and produced waters have the ability to concentrate naturally occurring radionuclides. These radioactive materials can be further concentrated in the wastes produced at the facilities and even in their products. They can accumulate as scaling inside pipes or as sludge precipitating out of wastewater and expose workers to levels of radiation far higher than OSHA standards. An OSHA hazard information bulletin suggested that “it is not unrealistic to expect (radioactive) contamination at all oil and gas production sites and pipe handling facilities”. However, there are currently no steps being taken to protect employees from radiation exposure as far as TENORM is concerned because the EPA has exempted oil and gas waste from federal hazardous waste regulations under the RCRA (Resource Conservation and Recovery Act). Lawsuits The natural gas industry has responded to state and local regulations and prohibitions with two primary types of lawsuits: preemption challenges, which argue that federal law prevents state governments from passing fracking restrictions, and Takings Clause challenges, which argue that the federal constitution entitles a company to compensation when a fracking ban or limitation renders that company's land useless. In September 2010, a lawsuit was filed in Pennsylvania alleging that Southwestern Energy Company contaminated aquifers