Quarrying rocks and minerals has been an important resource for building human infrastructure for thousands of years. The modern industrial-scale quarrying of substances such as limestone places great stresses on the environment.
Waste Water Discharge
Nearly all mining processes generate vast amounts of waste water, and limestone quarrying is no exception. Water is used for tasks such as cutting with high-pressure jets and the lubrication of solid cutting tools. The waste water can be recycled to a limited degree, but ultimately it will become befouled and useless for quarrying. Contaminants can include unnatural substances like oil and gas from machinery and also include natural sediments in excessive quantities.
Waste water discharge bearing high sediment content and the sediment from cutting are problematic. Increased sediment loads can choke aquatic species downstream from mining operations or even begin to calcify the environment. Calcium carbonate, found in limestone, is an important mineral for many animals, especially hard-shelled bivalves and mollusks. Like any other substance, though, too much calcium carbonate can be dangerous. Calcium that builds up within an organism can harden soft tissues and disrupt internal processes.
Water Table Depletion
Limestone often forms from dissolved minerals in water, which means many limestone quarries must have the water pumped out to access deposits. Over-pumping lowers the water table with hazardous consequences. If a mine is near coastal ranges, depletion of groundwater allows for saltwater to intrude further inland. Natural springs fed by the underground movement of water cease to flow if the pressure is reduced enough, with the possibility of disrupting ecosystems and even human water sources.
Noise and Air Pollution
Two atmospheric environmental consequences of quarrying are the noise produced from mining machinery and the high levels of dust thrown up into the air. Depending on wind patterns or surrounding cover, airborne dust can travel many miles from a mining site and affect the health of downwind residents, especially those with preexisting lung issues. Noise pollution from the heavy equipment used in quarries can drive back local wildlife as well.
The loss of habitat and subsequent depletion of diversity is one of the most worrisome problems associated with quarrying. Many of the other problems, like sedimentation and water table depletion, cumulatively affect surrounding habitats, even if habitats are not directly excavated or depleted by mining activities. Some problems of quarrying can be remediated, like pumping water back into the mine to help correct water table levels, but generally once habitat is lost, it cannot recover fast enough to restore ecosystem productivity to pre-mining conditions.