Landfill leachate is extremely common, but it’s also quite difficult to treat. While there are a few different types of leachate treatment methods, all have their challenges. Below, we’ll take a closer look leachate and why it’s so tough to treat effectively.
What is landfill leachate?
In a general sense, leachate refers to any kind of liquid that passes through a material and extracts components of that material — whether they be soluble or suspended solids — in the process. To put it into a landfill context, when leachate passes through landfill material, it picks up elevated concentrations of undesirable components, like organic materials, heavy metals, and other dissolved solids that could potentially be hazardous to the environment and to humans.
Why is it so important to treat landfill leachate?
Leachate often contains high concentrations of organic contaminants, as well as ammonia and/or methane. Fresh leachate contains the most pathogenic organisms, but toxic substances may be in leachate of any age. Not only do these contaminants pose a significant risk to the environment, but in treatment plants with poor ventilation, methane gas could be released and threaten the lives of those who work there. In addition, methane and other contaminants could get into the public sewer system. While most landfill sites will use leachate treatment tanks or will have an off-site treatment system, leachate from older or illegal sites are still very much an issue. The leachate from these sites can end up directly in bodies or water or the public water system and can negatively impact every species.
How is leachate usually treated?
In the past, landfill leachate was pumped off-site or hauled away to a wastewater treatment system for disposal. But due to stricter regulations for off-site disposal, many facilities will have leachate tanks on-site. Leachate treatment tanks eliminate the need for disposal or hauling costs while fulfilling the requirements for treatment. The treatment process can be accomplished through several different types of technologies, including biological treatment, physical or chemical treatment, and even reverse osmosis and evaporation.
What are the difficulties involved with leachate treatment?
For one thing, most landfills need to use a combination of methods to achieve the best results. In addition, leachate is always produced in different volumes and with different qualities. The leachate itself can also be impacted by precipitation, as well as the age and makeup of the waste around it. Many systems require constant monitoring and maintenance to ensure the surrounding environment and residents are safe. Because the regulations are so strict (for good reason), it can be a challenge to treat leachate effectively. But with new emerging technologies and the use of customized leachate treatment tanks, these organizations are in a better position to keep the planet, and those who inhabit it, safe.