If you work in an industry like manufacturing, construction or oil and gas, waste generation is an inevitable part of your everyday operations. Correct disposal is essential, and proper liquid waste management is particularly critical because of its potential for unexpected leaks, discharges and runoff. 

Fortunately, many options exist for ensuring effective, responsible, compliant liquid waste disposal. The guide below will discuss how to dispose of liquid waste and evaluate your waste disposal options.

Proper liquid waste disposal is essential — so much so that disposal is often heavily regulated and tiny infractions could incur hefty fines. Your facility will need to pay careful attention to the details of liquid waste disposal to ensure your processes are correct and compliant.

Why is correct liquid waste disposal so critical? Here are a few reasons:

Liquid waste may come in a few different forms:

Below are seven of the most common liquid waste disposal processes:

Dewatering works well to compact nonhazardous waste and make it more suitable for disposal. In this process, the facility generally pumps the liquid waste into a sturdy bag and removes the water, leaving only solid waste. A landfill typically does not accept free liquid, but the solid, nonhazardous waste can go to the landfill for disposal. The water receives filtration and treatment as necessary.

One common option for liquid waste dewatering, especially for sludge, is centrifugal dewatering and thickening. This process uses a cylindrical vessel to generate centrifugal force, which flings solids from the liquid and causes them to form a soft substance known as cake. 

Sedimentation is similar to dewatering in that it separates water from solid waste. It uses gravity instead of centrifugal force to pull the two states of matter apart. 

During sedimentation, a facility leaves its liquid waste in a sedimentation basin. As long as liquid waste flows quickly, its velocity is often enough to keep solid particles in suspension, so the design of a sedimentation basin reduces that velocity. As the wastewater flows slowly through the basin, solid suspended particles settle to the bottom in a layer of sludge. 

The facility can then remove the solids, leaving the solid sediment waste behind. Once the water and solid waste have separated, the water can undergo treatment, and the solid waste can go to a landfill. 

Alternatively, facilities can turn their liquid nonhazardous waste into compost. The facility first removes the water from the waste, leaving behind organic matter that contains nutrients like nitrogen, potassium and sodium. Using naturally occurring microorganisms, the facility can then turn the material into organic fertilizer that will also contain these beneficial nutrients to help crops and other plants grow. 

Compared to many other methods of liquid waste disposal, composting is relatively inexpensive. It is also exceptionally easy on the environment — even advantageous for soil and plant growth. 

Sometimes facilities dispose of their hazardous waste by incinerating it. The heat from specialized furnaces can remove acids, chemicals, oils, rock tailings, slag and other waste matter, leaving only water behind. There are two types of furnaces used for this technique:

Incineration is not always an ideal method of liquid waste disposal. Unlike the techniques laid out above, incineration is hard on the environment because it releases toxic contaminants and greenhouse gases into the atmosphere. It can reduce air quality, exacerbate asthma and other respiratory conditions and contribute to climate change. Incinerators are also expensive to install, maintain and run. In some cases, though, facilities turn to incineration because it is effective and leaves little waste behind to require further disposal. 

Root-zone treatment is most useful for relatively clean domestic wastewaters like kitchen water and bathroom shower and sink water. This treatment is a complex method that sends liquid waste through a sedimentation tank and then through various additional filtration processes — including, ultimately, the roots of growing plants. The result is water that meets the necessary standards for release into the environment. 

Root-zone treatment may employ a succession of filtration processes like these:

Root-zone treatment offers many benefits. It typically uses gravity — the water flows downhill from stage to stage, so pump and valve requirements are minimal. It is also exceptionally environmentally friendly — root-zone technology uses only 20% of the energy of a typical sewage treatment plant. And an established plant bed typically requires very little maintenance. 

Because it contains so many elements, though, root-zone treatment can be expensive to perform, and its complex installation means it may not be available in some areas. 

Liquid waste solidification involves adding binding agents to wastewater until the waste forms a compact, rigid, easily disposable solid. Many solidification processes use lime ash, sawdust, cement kiln dust, lime kiln dust, gypsum, phosphate or fly dust to add bulk and rigidity to liquid waste, or they may use asphalt or cement for added reinforcement. After solidification, companies can ship the solid blocks of waste to approved landfills for disposal or waste-to-energy facilities for incineration and energy generation. 

Solidification often combines with a process known as stabilization. Solidification alters the waste's physical properties, making it harder, stronger or less permeable and enclosing any hazardous contents. Stabilization makes it less likely for hazardous components to leak into the environment — for instance, by making them less mobile, soluble or toxic. 

One well-known example of solidification and stabilization practices in action is the Defense Waste Processing Facility in South Carolina, which is slowly converting 36 million gallons of high-level liquid nuclear waste into glassified solid waste. This conversion process makes the waste more stable and manageable until a secure federal repository can provide long-term storage. 

Some advanced, environmentally friendly solidification techniques can solidify liquid waste without adding other substances to it. These innovative techniques minimize waste and enable smaller landfill additions. 

Solidification is one of the cheapest methods of waste disposal, and easy to perform, but the extra solid material tends to make for a tremendous amount of refuse. The excess weight and bulk can sometimes lead to higher transportation and disposal costs, and it may require a disproportionate amount of space in the landfill. 

The remaining alternative is to dispose of the liquid waste as it is, often with the assistance of a professional waste management company. In this case, the facility collects its liquid waste in the appropriate drums. Then the waste management company picks them up, transports them and disposes of them according to applicable state and federal guidelines. This option is particularly appealing for companies that wish to remain compliant with regulations without investing significant time and energy into keeping up with them. 

No single waste disposal technique is most effective for every situation. When you choose a liquid waste disposal method, you'll need to weigh the pros and cons, assess your waste generation patterns and disposal requirements and make a decision that best suits your needs. Below are a few considerations to keep in mind as you deliberate:

Now that you know more about various liquid waste disposal methods, you can make your choice easier by partnering with a trusted, innovative, industry-leading waste management company — VLS. 

We are a full-service environmental company with extensive experience in handling all types of waste streams, including liquid waste, and disposing of them sustainably and responsibly. We provide compliant industrial wastewater treatment, liquid waste solidification, sludge and solvent waste removal and recycling and waste management. You have numerous options to bring you peace of mind concerning your waste management operation's safety and effectiveness.

Contact us to take advantage of our liquid waste management services, or browse the rest of our website to learn more.