Sanitary Sewer Overflows

The overflow of wastewater from a sanitary sewer system is considered a sanitary sewer overflow (SSO). Sanitary sewer overflows can lead to significant environmental, health and safety risks. Sanitary sewer overflow prevention is important in ensuring the safe and unimpeded transport of raw wastewater from each source to the City’s wastewater treatment plants.

What caused an SSO?

SSOs can be caused by anything capable of obstructing the flow of wastewater in a sewer. The build-up of solids and fats, oils and greases (FOG) in the wastewater collection system is a major concern. When an obstruction blocks the flow of wastewater within a pipe, the wastewater may back up and overflow through a manhole, cleanout, or drain. This overflowing wastewater may make its way into the environment, a house or a business.

What is the Pretreatment Program Doing to Prevent SSOs?

  • We investigate all sewer backups due to grease or other obstruction, in order to determine the source.
  • We now have a Special Billing Program in place to make those businesses that cause an SSO responsible for reimbursing the Harlingen Waterworks System for all expenses related to the incident.
  • We are currently working on clarifying our enforcement policy with regard to the prohibited use of certain enzymes, bacteria and other agents in grease traps.
  • Educate restaurant on how to help keep grease from going down the drain by handing out literature.

What can you do to prevent SSOs?

  • Collect waste cooking oil in a can. When cool, place this receptacle in a trash bag, seal tightly, and discard in the trash. Waste oil from restaurants can be collected and sold to rendering facilities;
  • Scrape food from plates into a trash can;
  • Before washing, wipe oily pans thoroughly with a used paper napkin or paper towel;
  • Minimize or avoid using your garbage disposals. A lot of food waste contains fats, oils and grease and could clog your own pipes and/or the city’s sanitary sewers;
  • Install and maintain baskets, screens and or strainers over all sinks and floor drains;
  • Spread the word to your friends and neighbors about what they can do to help prevent SSOs.