25 prevent unnecessary damage Where permitted companies often take the extra step of creating new or enhancing existing wetlands adding valuable habitat for waterfowl and other wildlife Air Quality Mining causes little impact on air quality Steps are taken by mining operations to suppress dust from haul roads rock crushing ore concentrating and the removal transport and storage of coal and minerals Major expenditures have been made by mineral smelting and refning operations to control emissions particularly of sul fur dioxide SO 2 SO 2 also fgures prominently as a concern in the use of coal where it is a byproduct of combustion by power plants However while coal use by US utilities increased from 320 million tons in 1970 to about 700 million tons at present SO 2 emissions dropped from 158 million tons annually to 12 million tons in 2019 In addition particulates from coalfred plants declined some 90 percent over the same period according to the US Envi ronmental Protection Agency EPA Wildlife and H abitat P rotection While w ild life protection or mitigation plan is required by law for todays mines many operations go well beyond the regulations to implement resource protection and habitat improvement programs Reclamation and water quality procedures are often designed to provide food shelter and an attractive environment for various native animal species Many operations institute specifc targeted projects including sav ing threatened amphibians providing B ald E agle nesting sites reintroducing once threatened spe cies such as the peregrine falcon and improving instream fsh habitat and population s F or many companies wildlife habitat restoration creation or enhancement is seen as the primary benefcial postmining land use Subsidence Planned s urface subsidence is usually gradual but can sometimes be the abrupt settlement of rock and soil layers above an under ground mine Any surface subsidence must be anticipated and accounted for in the plans for a mining operation In coal mining modern proce dures such as longwall mining technology provide mines with a more efective way of predicting and dealing with subsidence With longwall mining it is easier to anticipate when and where subsidence will occur usually immediately after the mining operation is completed in a given location This allows mine operators to carefully monitor changes in the surface and make repairs as needed working cooperatively with owners of surface structures Company subsidence programs also include atten tion to water resources ofering both temporary and permanent solutions to afected supplies Cu ltura l R es ourc es The National Historic Preservation Act and various state laws require assessment and protection of archaeological and historic resources located on federal and state lands Mining companies assess protect and mitigate where necessary disturbances to these resources and often work with state federal archaeological historic Native American tribal and other organizations to catalogue inventory or display artifacts and other items discovered during the extraction or reclamation process Some companies erect interpretive signs and centers to make relics available for viewing by the general public MINING and the ENVIR ONMENT