Groundwater pollution is a type of pollution which occurs when groundwater becomes contaminated. Around the world, groundwater pollution is a very serious and costly problem, and many governments have started to take aggressive action to address it. Once contaminated, groundwater is very expensive to clean up and make usable again, and in some cases, an aquifer may be so contaminated that it has to be abandoned, which can put tremendous pressure on a community as it attempts to find a new supply of water.
There are several different types of groundwater, ranging from water which flows freely through the ground and interacts with surface water to closed aquifers, which are theoretically very hard to contaminate. Groundwater becomes polluted when materials seep through the soil and reach the water, which can happen when rainfall washes contaminants into the ground, when polluted surface water connects with groundwater, and when buried tanks or waste disposal sites start to leach.
Any number of contaminants can end up groundwater, including sewage, prescription medications, agricultural chemicals, microorganisms, road salt, landfill seepage, petroleum products, chemicals, and hazardous waste such as nuclear waste. These contaminants make the water unsafe to drink, because they can cause severe health problems. The water may also be unsafe for use in agriculture or manufacturing, and it can cause issues for local wildlife and flora exposed to the contaminated water.
People usually identify groundwater pollution when people start getting sick while drinking it, or when routine testing of water supplies reveals contamination. People with wells are at a high risk of getting sick from polluted water, because plumes of contaminants can end up in some surprising places, and people who drink municipal water are also at risk, because groundwater supplies may be one of the sources used by a municipality to supply the water needs of the populace.
Once discovered, groundwater pollution needs to be addressed, both to clean the contaminated water and to prevent its spread. Finding the source of the contamination and cleaning it up or containing it is important, as is cleaning the water to make it safe for use. In cases where the water cannot be cleaned, it will be necessary to contain it so that the contaminants cannot form a plume in the soil and reach clean water supplies. Alternative supplies of water may need to be secured to meet water needs while the pollution is dealt with.
People can help prevent groundwater pollution by disposing of hazardous materials like oil, paint, unused prescriptions, and solvents responsibly in a facility which is certified to handle such materials. They can also lobby their lawmakers for more aggressive environmental legislation which is designed to reduce groundwater pollution by setting standards and empowering government agencies to enforce them.