Guest Column | July 6, 2015

Sanitary Sewer Overflows (SSOs) And Sewer Backups: Causes And Solutions

By Sheldon Primus

By Chris Kittleson, Sr. Safety & Risk Mgmt. Consultant - Public Risk Underwriters of Florida, Inc., and Sheldon Primus, P.O., M.P.A., C.O.S.S., CEO - Utility Compliance, Inc.

Wastewater collection systems are a series of pipes and water accumulation points known as lift stations. These networks of pipes move the wastewater by either gravity or pumped from one point to the next. Occasionally, there is an unintended sewage spill on the ground that occurs along the route to the treatment plant or a backup of flow to the resident that creates unsanitary conditions. This article will reveal common causes for sanitary sewer overflows (SSOs) and sewer backups and practical steps to mitigate all aspects of the issue.

Common Causes for SSOs and Backups

There is a long standing battle with wastewater professionals and the general public on what should be flushed down a toilet or poured down a drain. Restaurants must control waste materials such as fats, oils, and greases (FOG), because that material routinely inhibits the wastewater treatment plant’s ability to treat the waste stream. FOG is also a contributor in clogging pumps and pipes when released in large quantities.

Individual households with personal lift stations commonly called low pressure sewer systems (LPSS) are especially susceptible to having issues with backups if they pour waste oils down the drain. Most people see the liquid go down the drain and assume that it remains in that state. However, when it cools it becomes a gelatinous, semi-viscous material that will accumulate to a point where the LPSS pump will not be able to work effectively. Eventually, the LPSS will fail causing the backup of wastewater in the residence.

Another culprit for backups in residential homes are products that are labeled “flushable.” Flushable items are under increasing scrutiny for mislabeling their product to state that they are harmless to the collection system. In fact, several lawsuits are currently in the court system challenging that flushable products are not dispersible (breaks apart) as toilet paper. In most cases, the product doesn’t leave the customer’s LPSS because it will clog the pump.

Some items that routinely get flushed are women’s sanitary clothes, facial wipes, baby wipes, and tampons. All of these materials do not disperse like toilet paper and should be disposed of as solid waste, i.e., garbage. Wastewater pumps and piping are not designed to accommodate such discharges, therefore SSOs and backups occur when a community misuses their systems.    

Lift Station equipment failure is another common cause of SSOs for larger systems. If the utility does not have an effective maintenance program or the most practical pump for the waste that is being discharged, then the chances of an SSO increases. Regulatory agencies have stringent rules regarding reporting and treatment of spills, therefore the utility must be vigilant in eliminating any causes for a SSO.

Solutions for SSOs and Sewer Backups

Basic solutions for issues such as disposable wipes and FOG are for the utility to hold outreach and public education sessions on the issue. Give the public the knowledge of how the collection system was intended to work and the challenges of discharges such as FOG and “flushable” products. Many organizations send envelope stuffers or door hangers with educational material for the residents.

Another effective way to reduce or eliminate FOG and disposable wipes is by public service campaigns and slogans such as the following videos:

Lift stations equipment manufacturers have used technology to design better pumps, screening units, and macerators to combat the issue. The utility should contact the manufacture of their equipment to verify if there is more suitable equipment available for the problem waste materials.

SSOs and Sewer Backups Mitigation

A “rule of thumb” is that if the backup is as a result of a blockage on the property of the customer, then the responsibility/liability is on the customer. If the blockage occurs away from the customer’s property, then the responsibility is with the utility. Based on that, either the utility (or their insurer) or the customer should immediately provide services to remove the blockage and begin cleanup if the backup is into the customer’s home/building. The next step is to report the incident to a claims administrator, which will complete the liability investigation to determine liability.

It is recommended that the utility keep a list of at least three cleanup contractors that they can contact 24/7 should a backup occur. It is important that the cleanup efforts begin immediately to help mitigate the damages. As a matter of clarification, the customer has a duty to mitigate their damages no matter who is at fault. As a matter of practicality it is most important to get the blockage cleared and get cleanup efforts underway in order to calm an irate customer.