Quarries get a lot of flak from environmentalists.
Quarries are bad for the environment as they contribute to deforestation, create pollution, and more.
Here’s everything you need to know about the environmental impact of quarries.
How Do Quarries Affect the Environment?
1. Water Footprint
Quarries have a high water footprint, which can vary based on location and what material is being extracted.
For example, extracting bentonite could have a water footprint of 48 liters of water per tonne.
For perlite, it’s about 70 L/t, while pozzolan type 1 has a water footprint of 30 L/t and type 2 180 L/t.
2. Water Pollution
Quarries can be a source of water pollution, as digging for the likes of rock or gravel can also release other harmful substances into the surrounding environment.
As a result, quarries can pollute both surface water and groundwater.
Research found there was a higher concentration of fluoride in the water in Indian villages near or within limestone and sandstone quarries.
Quarrying can also release heavy metals and sulfate minerals.
In drinking water, these substances can be harmful to both animals and humans.
3. Non-renewable Materials
Quarries are used to source stone, sand, and aggregates, which are non-renewable materials.
So, quarries further the reliance on unsustainable compounds.
Land must be cleared to create a quarry which can disrupt a pre-existing ecosystem, resulting in land degradation and the loss of vegetation.
This displaces animals who live in the area and can leave them struggling to find food and shelter or force them into urban areas where they’re seen as pests.
5. Noise Pollution
Quarries are also a source of noise pollution.
Research found when reading the noise levels from blasting activities at quarries for ten days, the noise ranged from 102.8 to 130.8 decibels.
During crushing activities, they reached between 97 and 116.2 dB – however, another study focusing on a crushing unit in Bangalore found it could range from 133 to 156 dB.
For workers, being exposed to loud noises without ear protection can cause hearing loss as well as negative psychological effects.
It can also be harmful to wildlife in the surrounding area.
Excess noise can cause hearing loss and stress in animals but can also impact predator-prey relationships.
Noise pollution means animals will not hear predators approaching, but it can also mean that many predators cannot track prey if they cannot hear them, so this disrupts the ecological balance.
Vibrations in the ground and air associated with quarrying may also startle wildlife.
Quarrying can generate huge amounts of waste as unwanted materials can be dug up.
For example, mining bentonite can generate around 0.83 m3 of waste per tonne, while perlite could be behind 0.39 m3 /t.
Meanwhile, pozzolan one and two do not seem to generate waste as they are homogenized. Some of the waste may be recycled.
7. Dust Pollution
As quarries are open-air mines, they can spread dust pollution.
This can spread harmful compounds into the surrounding area.
Should layers of dust settle in other areas, it can kill plants as they can no longer photosynthesize as well as halt the growth of seedlings if they are completely sheltered from the sun.
This can reduce crop yields and also leave animals struggling to find food.
The concentration of dust associated with the crushing process can range from 100 to 40,000 μg/m3 and up to 110,000 μg/m3 for the drilling process.
The amount of dust pollution may differ depending on what material is being quarried.
For example, as perlite has low moisture, it releases the most dust when it is being processed, while pozzolan releases the least.
Exposure to dust can also increase the risk of allergies and cancer and impact lung function.
Do Quarries Contribute to Climate Change?
Quarries do contribute to climate change.
The carbon footprint of a quarry varies based on what is being mined.
Quarries release greenhouse gasses. They also contribute to climate change because they are energy-intensive as machinery needs to be operated.
Much of the carbon footprint is also associated with transportation.
As electricity generation around the world is still mostly reliant on fossil fuels, this is unsustainable and polluting.
A lot of the equipment used to power quarry equipment also uses oil as fuel, which is another reason they contribute to climate change; oil is a non-renewable material sourced via mining.
For example, quarrying bentonite uses about 965,000 l/y of oil, while transport could account for 612,427 l/y.
As for releasing carbon dioxide, extracting bentonite could emit approximately 1.52 mg/nm3, while perlite could release around 2.18 mg/nm3.
Quarries are often built over grasslands and forests; up to 20% of global greenhouse gas emissions are associated with the likes of quarrying, construction, and land use conversion.
Carbon dioxide is also not the only compound released from quarrying; it can also release carbon monoxide (CO), nitrogen oxides (NOx), and sulfur dioxide (SO2).
While it is widely known that carbon dioxide contributes to the greenhouse effect, some of these compounds also contribute to global warming.
Meanwhile, when sulfur dioxide comes into contact with other substances in the atmosphere, it can result in acid rain.
For example, bentonite can release around 31.38 mg/m3 of CO, 99.48 mg/m3 of NOx, and 5.31 mg/m3 of SO2.
Perlite could be behind around 23.30 of CO, 131.91 mg/m3 of NOx, and 0.85 mg/m3 of SO2.
Are There Eco-Friendly Quarries?
There do not seem to be any eco-friendly quarries, but there may be ways to make them less environmentally destructive.
Quarries should be filled in after they have been exhausted.
It is also best to replant native trees and plants to attract insects and animals back to the area and restore the ecosystem.
With the use of silencers on equipment, quarries can also reduce noise pollution.
Quarries can also manage their waste better; rather than disposing of unwanted aggregates, like crushed stone, these materials can actually be used in construction work.