Some people call them the Environmental Pollution Agency because the EPA is responsible for determining how much pollution an industry is allowed to emit before their pollution is deemed harmful to the environment and a health hazard, especially to the people who live nearby. Companies are issued permits that outline the rules to which a company can pollute and still operate within the law.
When done fairly, this process works pretty good. Of course, no amount of pollution is good and it’s virtually impossible for a smoke stack not toss out some pollutants.
Each state has an environmental agency that does the dirty work under EPA guidance at issuing these permits along with regulating industries to operate within the permit limits. When companies disobey, they get fined and if they continue to disobey, they can be put out of business.