Pay Now or Pay a Lot More Later: The Importance of Sewer Maintenance

Pay Now or Pay a Lot More Later: The Importance of Sewer Maintenance
By: SDD Engineering Staff

A classic oil filter commercial highlighted the significance of routine maintenance, particularly the necessity of keeping engine oil and filters clean. That commercial’s iconic tagline was, “You can pay a little now, or pay a LOT later.” The underlying message was unmistakable: preventative maintenance is far more cost-effective than replacement costs for new.

The Sanitary District of Decatur manages over 65 miles of gravity sewer piping, 28 miles of pressure force mains, and 41 pump stations, which efficiently transport wastewater from the communities of Mount Zion, Argenta, Oreana, Forsyth, and Decatur to its regional wastewater resource recovery facility (WRRF).

The district’s primary objective is to clean wastewater and safely reintegrate it into the environment. This goal can only be accomplished through diligent infrastructure maintenance much like we take care of our vehicle engines. A catastrophic failure within a sewer system can result in road collapses, the emergence of sinkholes, and contamination of water supplies. Such incidents can have lasting detrimental effects on our environment and pose significant risks to human life.

Wastewater is a messy business!  In our world, we need to protect against potential erosion, corrosion, and even explosions.

Erosion: When we think of erosion, we often picture rainwater runoff transporting soil, rivers carving into rocks, or landslides displacing vast amounts of material to reshape the landscape. If routine maintenance of a gravity sewer system is not performed the potential for sand, dirt, grit, and “solids” is also a significant concern. As wastewater flows through pipes, it can gradually alter their structure, much like a river erodes rocks over time.

Wastewater in motion, will wear down the surfaces it encounters, and the introduction of additional grit can exacerbate the erosion of pipe thickness and their protective coatings.

The blockage of pipes, like the infiltration of tree roots, can constrict flow which, in turn, increases water velocity. This process could also lead to serious issues such as sewer backups, overflows, and environmental cleanups should the flow be blocked too much. Ultimately, these problems are not merely inconvenient; they represent significant financial burdens.

Erosion is happening all around us. Sometimes it is fast and easily noticeable, other times it is slow and happens over decades. Whichever the case, erosion causes damage that will need to be fixed.

Corrosion: Sanitary sewer systems are designed to deliver wastewater to the Wastewater Reclamation Facility for treatment and sanitizing.  Left clogged, water movement slows, creating pipes where anaerobic bacteria can flourish.  A byproduct of these bacteria is hydrogen sulfide (H₂S) gas which converts to highly corrosive sulfuric acid.  Many older collection systems are constructed with concrete, vitreous clay, or iron piping, which are very strong, but are also susceptible to chemical corrosion.  Exposure to corrosive chemicals like sulfuric acid weakens these materials, decreasing the lifespan of the pipe and accelerating the need for expensive replacement or rehabilitation of these older pipes.  Routine cleaning and maintenance of the sewer system removes these obstructions and reduces water standing still in sewer piping, which promotes the growth of these bacteria.  The freely flowing water limits production of the hydrogen sulfide gas, minimizing the formation of sulfuric acid, and protects the piping from excess chemical corrosion.

Explosion:  Similar to how gravity sewer pipes transport water, they also facilitate the movement of gases within the pipe space above the waterline. Sewer gas is often characterized by a distinct odor reminiscent of “rotten eggs,” which serves as a clear indicator of the presence of hydrogen sulfide in the environment. At elevated concentrations, hydrogen sulfide can reduce the oxygen levels in the surrounding air, and at even higher concentrations, it poses an explosion risk. Just ask Cousin Eddy from the movie ‘Christmas Vacation’.

Although such explosive concentrations are uncommon, it is important to understand that a well-maintained and properly functioning sewer system, one in which the sewer flow is consistently active, will mitigate the risk of these hazardous concentrations.

The cost of installing sewers can vary significantly based on factors such as pipe size, sewer depth, material used, and accessibility to the construction site. The most effective management strategy is to conduct maintenance proactively, as this approach is safer, more cost-effective, and less unpleasant for our senses.