News

FATS, OILS, AND GREASE IN SEWER LINES CREATES HARDENED DEPOSITS OF SOAP
07/13/2011

On a daily basis the Emerald Coast Utilities Authority (ECUA) wages a war against fats, oils, and grease (FOG); trying to keep these cooking by-products from entering into the wastewater collection and treatment systems. Nationwide, about twenty-two percent of sanitary sewer overflows (SSO’s) are caused by accumulations of FOG. Researchers at North Carolina State University (NCSU) recently made a surprising discovery, the grayish-white, gritty formations that look like stalactites along the walls of sewer pipes are actually soap deposits. The fatty acids in the FOG chemically react in the collection system to form the hardened “soap” deposits that often cause SSO’s.

Gabe Brown, ECUA environmental specialist says, “The large amounts of FOG we find in the wastewater cause blockages and decreases pipe capacity, and therefore, are a major reason of sewage spills and sewage backups in homes and businesses. These backups and spills can instigate environmental and public-health problems, and lead to costly fines and repairs.”

The NCSU research team used a technique called Fourier Transform Infrared (FTIR) spectroscopy to determine the composition of the FOG deposits at the molecular level. Using this technique, researchers found that the hardened deposits were made of calcium-based fatty acid salts-or soap. With an understanding of how these deposits form, researchers are one more step closer to controlling SSO’s caused by FOG deposits.

To reduce the amount of impurities that enter into the sewage system, homeowners and businesses are asked to never wash FOG down the drain, even with hot water and soap. The following disposal methods are environmentally friendly, safe, and recommended:

  • Never pour FOG down the drain, sink or garbage disposal.                                                 
  • Pour FOG into jars, cans, and plastic tubs. Let contents cool and solidify. When the container is full, throw away with your trash.                                                                                                                                      
  • Mix cooking oil with an absorbent material such as cat litter or coffee grounds, place in a container (lid securely fastened) for disposal with your trash.
  • For greasy pans, pour off the grease into a container, and use a paper towel to wipe out the remaining grease in the pan prior to washing.
  • Store the container in the freezer, which will keep the grease solid, and pull it out whenever you have fats, oils and grease to dispose of. When it gets full, dump the whole container into the trash.

To learn more about the FOG environmental program, and receive additional information, visit www.ecua.fl.gov.