In 2019, contamination may be the furthest thing from our minds. We’re accustomed to clean drinking water, ripe fruits and fresh vegetables. For the most part, we don’t have to worry about getting sick from something we consume. Even though environmental regulations are enforced, it’s not impossible for contaminants to enter our soil and groundwater. Check out these 10 common sources of contamination that can affect our everyday lives.
1. Dry cleaners
While modern dry cleaners are generally clean and efficient, this wasn’t always the case. Historical use of trichloroethylene and tetrachloroethylene in dry cleaning operations was poorly regulated and often led to the release of these chemicals – called chlorinated solvents – into the environment. Chlorinated solvents easily dissolve into groundwater and are extremely volatile and carcinogenic.
2. Agricultural chemicals
Pesticides and herbicides, designed to kill plants and animals, can have adverse effects on human health. While certain pesticides and herbicides have been banned in most parts of the world, the specific design of these chemicals makes them very persistent once released. Due to their widespread use, pesticides and herbicides can be found any and everywhere – from former fields to residential settings – even if they haven’t been legally used in decades. Even modern herbicides like glyphosate are hazardous to the environment and human health.
3. Gas stations
There is no such thing as a “clean” gas station. Almost every underground storage tank will eventually leak. Tankers restocking gasoline and diesel at filling stations can overfill and spill tanks. People drive off with fuel dispensers in their car. Emissions of fuel into the environment happen every day.
Protections to prevent and catalog releases in the form of environmental regulations have significantly improved, but releases still occur. Before 1988, anyone with the funds necessary to purchase an underground storage tank could start a gas station with zero regulations or protections in place. Though many of these older gas stations are now shut down, most owners simply walked away, leaving thousands of gallons of gas or diesel in the ground.
4. Vehicle use
Outside of the contamination caused by gas stations, the burning of gasoline and diesel by cars creates issues. A family of contaminants called polycyclic aromatic hydrocarbons is a direct result of gasoline and diesel consumption. These contaminants are persistent in the environment and, due to the widespread use of automobiles, everywhere in the soil of urban areas. In fact, they are so common that the background concentrations in urban soil are often above the EPA screening levels for most constituents.
Landfills are contaminated, and it’s no mystery why – it’s where trash goes. Not just coffee grounds and chip bags, but industrial waste as well. Thankfully, modern landfills are well-designed and diligently monitored to prevent leakage from waste interred into the surrounding area. However, historic landfills were not. Decades ago, all that was needed to start a landfill was a hole in the ground. No protections were put in place to prevent chemicals from the landfill from contaminating groundwater sources. Sadly, in many cases, these old landfills are doing just that.
6. Industrial manufacturers
EPA regulations have prevented and curtailed the environmental impact from the release of hazardous chemicals from industrial manufacturers, but releases can still happen. Manufacturing in modern society produces some type of hazardous byproduct, which is occasionally spilled or released into the environment. Historically, industrial manufacturers could dump any type of waste into the nearest body of water without consequence. While we are (mostly) no longer doing that, the sheer volume of hazardous materials produced by industrial manufacturers is reason enough for a place on this list.
7. Military operations
We all appreciate those who serve in the military, but the day-to-day operations of military services is a massive source of environmental contamination. Ammunition dumps, firing ranges, masses of fuel-burning vehicles and multiple other sources can all be found at military bases. These bases also have fuel tanks, dry cleaners and landfills along with every other source of contamination the civilian world has, except they’re concentrated in one small area.
8. Generation of electricity
Generation of electricity is one of the primary sources for contamination, not only in the form of greenhouse gases in the atmosphere but also of soil and groundwater. The burning of coal creates coal ash, which contains hazardous levels of metals, such as arsenic and lead, along with volatile and semi-volatile contaminants. In addition to the contamination associated with electricity generated by burning fossil fuels, the oils previously used in transformers contained PCBs. It goes without saying that the practices used to obtain the fuels needed for the generation of electricity are devastating to the environment. Mining for coal, fracking for natural gas and drilling for oil, along with oil spills created by the transport of materials in ships, trains and pipelines, have been well-documented in their impact on the environment.
9. Urban runoff
Urban runoff is a major source of contamination. Think of everything that winds up on the concrete in an urban area – oils, gas, cleaning products, etc. Every time it rains, runoff enters drains, eventually reaching a river, lake or ocean.
10. Soil erosion
When construction projects remove existing grass and vegetation from a piece of land, the underlying soil is exposed to precipitation and wind. Subsequently, erosion occurs, and the soil is carried downstream by rain or wind as it travels across the property. One of the worst culprits for surface water contamination in our area is the clayey soil that turns our water brown.