Liquid Waste

What is Liquid Waste?

Liquid waste is a major problem in the world, due to approximately 71% of the Earth’s surface being covered in water. According to the Environmental Protection Agency (EPA), liquid waste is defined as any waste material that passes the definition of a “liquid.” This means that the material must, “pass through a 0.45 micron filter at a pressure differential of 75 psi,” according to the EPA’s provided definition of a liquid (1). The main producers of liquid waste are animals and human beings as natural excretion of waste is flushed into sewage and waste lines.

Why is Liquid Waste Important?

Liquid waste is such an important category of waste management because it is so difficult to deal with. Unlike solid wastes, liquid wastes cannot be easily picked up and removed from an environment. Liquid wastes spread out, and easily pollute other sources of liquid if brought into contact. This type of waste can also soak into objects such as soil and groundwater. This pollution then carries over to pollute the plants we eat, the animals in the ecosystem, as well as the humans within the area of the pollution.


Aging Wastewater Treatment Infrastructure in the U.S.

Wastewater treatment infrastructure in the U.S. has grown slowly over the past years, with only $45 billion of the estimated $271 billion raised for improvements so far. This means that currently 76% of the population in the U.S. are relying on only 14,748 water treatment plants (3). These plants are also becoming less and less efficient each year due to buildup within piping aging equipment. Many of the treatment plants currently in operation cannot keep up with the amount of liquid waste they are receiving, which results in over-spill into lakes and rivers.



  1. Friedman, D. (1981, June 6). Definition of “Liquid Waste”. In National Service Center for Environmental Publications. Retrieved March 19, 2017, from
  2. Wastewater Stats in the U.S. (2013, September 10). In Public Works. Retrieved March 19, 2017, from
  3. ‘Wastewater.’ Infrastrucure Report Card, ASCE, 2017, Accessed 19 Mar. 2017.
  4. “Wastewater: Where does it go?.” YouTube, DetroitRiverCC, 30 Nov. 2012, Accessed 20 Mar. 2017.