The Value and Benefits of Septage Technology
Understanding the Value and Benefits of a Septage Receiving System
With more than 21 million septic systems in the US, many communities depend on liquid waste haulers to empty these septic systems and transport the non-hazardous liquid waste, or septage, to receiving stations. The purpose of a septage receiving station is to remove the trash present in the septage waste stream before it enters the treatment process.
Septage receiving stations help protect the community and the environment and also serve as a source of revenue for the wastewater treatment plant.
Septage: What is it?
Septage can come from several sources:
- Residential septic tank cleanout
- Restaurant fats, oil, and grease removal
- Sewer line cleanout
- Lift station cleanout
- Portable restroom
- Landfill leachate
Before septage can be passed to a wastewater treatment plant, the receiving station must first remove trash, grit, rags, and debris.
Many municipal wastewater treatment facilities in the US receive domestic septage. The term “domestic septage”, as defined in federal regulations (part 503), refers to solid or liquid waste removed from residential septic tanks, portable toilets, type III marine sanitation devices, or any device that stores domestic waste (such as household, non-commercial, non-industrial sewage). Domestic septage generally contains fecal matter, rags, grit, and fats, oil, and grease (FOG) from cooking waste.
By contrast, commercial and industrial septage refers to material pumped from septic tanks or other devices used in the collection, pretreatment, or treatment of any water-borne waste resulting from any process of industry, manufacturing, trade, or business where the design disposal of the wastewater is below the ground surface. Commercial and industrial septage can contain automobile chemicals, cleaning chemicals, common solvents, FOG, rags, and medical waste.
Challenges of Septage Processing
Septage is not the same as typical wastewater and can be the most difficult waste stream to a wastewater treatment plant. Septage is more concentrated in rocks, rags, grit, FOG, and biochemical oxygen demand (BOD) nutrients. In fact, each of these categories – solids, FOG, BOD, rags – can be as much as 30-100 times greater than those found in typical wastewater.
Once the waste haulers collect the septage from around the community, they deliver it to a receiving station at the plant for treatment. The septage receiving station removes inorganic solids as a first step before treatment at wastewater treatment plants and private liquid waste processing facilities.
Key components in the process include:
- Screening. Screens separate trash from water and conveys the trash to compactors.
- Compactor. The compactor removes water from the screened trash and crushes solids to a smaller volume.
- System control. System controllers provide automatic operation, including automatic wash, self-correction, constant monitoring, and system access.
To learn more about the challenges of septage receiving, download the full article.
Benefits of Utilizing the Proper Septage Processing Technology
Given the processing demands of septage, using the right technology can greatly enhance the longevity of the equipment, increase throughput, and lower maintenance costs. Additionally, using equipment properly designed to process septage can provide benefits to downstream equipment including:
- Prevent fouled pump internals. By reducing the amount of rags, FOG, and grit will reduce the chances of clogging the pumps.
- Minimize pump impeller wear. Similarly, effective screening improves pump impeller performance and extends their useful life.
- Minimize fouled downstream aeration systems and reduce debris floating in downstream clarifiers. Effective screening early in the process also reduces the amount of solids that make their way downstream, extending the useful life of downstream equipment as well.
- Reduced operation and maintenance labor costs. A properly designed system will significantly reduce O&M labor costs.
- Extended equipment life. Leveraging the right design and components will extend equipment life by as much as two times longer than poorly designed systems or inferior components.
Best Practices of Septage Receiving Technology
Some best practices to reduce continuing operating costs include:
- Minimize or eliminate human interaction with septage. For example, operators should not have to remove rocks from rock traps, manually power wash fouled or blinded system components.
- Periodic system cleaning should be automatic. There should never be a time when an operator must enter a tank containing screening or compaction.
- Design for peak flows. Be prepared for peak flows with high rag and grit content to limit screen blinding.
- Debris removal. Include components that have the ability to grind up rocks, remove debris, and automatically flush tanks and screens to avoid damage to system components.
The system should be designed for speed. Minimize the downtime and get the haulers in and out of the facility quickly and efficiently. Equipment failures or frequent required maintenance will slow down the process. Robust screening and compacting will keep the process moving.
If you would like to discuss your specific needs, connect with Hydro-Dyne’s highly experienced professionals for more information about our Dusky Shark Septage Receiving Station.