Septage receiving is a valuable service that clean-water plants can offer to rural communities, and it can be a significant source of revenue.

A key to a beneficial septage program is a clean and efficient receiving station that makes life easy for haulers and plant personnel. In general, the more the receiving functions are automated, the better for everyone. Franklin Miller now offers the SPIRALIFT SR multifunction septage receiving system. It’s a single unit that grinds, screens and conditions the flow to reduce the loading on plant processes and prepares screened solids for an economical next step.

Besides its wastewater processing functions, it authenticates users and records transactions for billing and tracking. The unit washes screenings and efficiently compacts them by up to 40%. The solids are delivered to a convenient elevation for discharge to a bin, bag or conveyor.

The unit can be configured to receive grease, septage or both. The screening system is housed in a stainless steel tank enclosure. An automated rock-removal system is optional. Bill Galanty, Franklin Miller president, and Gary Carlson, engineer, talked about the system in an interview with Treatment Plant Operator.

What needs is this technology designed to meet in the marketplace?

Galanty: Customers have basic needs on the mechanical side and the financial side. Mechanically, they have a need to receive septage in an organized way from the hauler trucks without overloading their processes. On the financial side, they have a need to be paid accurately and reliably for receiving the material.

What is the essential benefit of a septage receiving station?

Carlson: It’s very important to many customers to operate a system that can neatly and effectively process the septage. In many cases, septage haulers just dump the material into an open manhole. It goes right into the treatment system, and it’s such concentrated sewage that it can upset the balance of the process. Our technology is essentially a pretreatment unit that makes septage easier for them to deal with. The machine grinds and screens the material, separates out the solids and eases the loading on the headworks.

In basic terms, how does the process work?

Carlson: It starts with a quick-connect coupling that connects to a hose from the hauler. The first treatment stage is a rock trap. Right after that within the housing there is a coarse grinder that cuts the rags, plastics and other solids into particles. That makes the flow much more manageable for the screening equipment, optimizes washing and protects the valve. After that, we can measure the volume with a flowmeter, or the material just goes through a plug valve into the septage receiver tank.

What happens in that receiver tank?

Carlson: Inside is a spiral screen that takes out the inorganic material. Then the screenings are washed and cleaned in a very intensive spray wash system. That is very important, especially where the treatment facility doesn’t have permitting to put dirty screenings into a landfill. There is also a built-in self-cleaning system for washing the interior of the tank to keep the system hygienic. The organics come out with the liquid, and that is typically piped into the treatment plant headworks.

What is done with the screenings after washing?

Carlson: The screenings are transported into a compaction area that uses proprietary technology. We have a compaction process that is high strength and very effective. 

What would you say are some key advantages of this technology?

Galanty: A number of special features and know-how have gone into this machine. Franklin Miller started out as a grinder manufacturer. Our grinder uses a cutter cartridge technology that makes it strong and resistant to the heavy solids encountered in septage. A lot of maintenance issues are eliminated by the use of a properly designed grinder. At the screening stage, we have an oversized screen that allows plenty of capacity for very thick, high-solids material. Also, our screen has individual, easily replaceable brushes.

How does the rock removal system function?

Carlson: Very often rocks and bricks are sucked up into the vacuum trucks and have to be separated out, which our system does with the rock trap. Cleaning that trap is a job nobody wants, but it’s an extremely important job. The rock removal system has a screw conveyor that cleans out the belly of the trap at intervals the user can program and conveys the rocks to a bin.  

Are there any other options that enhance performance?

Galanty: The machine can come with secondary and tertiary processes. We have an option for grit removal and for a grease skimmer. That makes it a three-stage solids removal system.

How does this technology handle the financial side of septage receiving?

Galanty: Many plants depend on an honor system. Our system is automated. We record the flow, and we record the identity of the hauler by giving them a card that they swipe. If they have an account but are not in good financial standing, or if they’re not recognized, the system will not open. We can also measure and record the pH. That helps keep plants from receiving caustic materials they would rather not have to deal with. Beyond that, we have software that plants can use for invoicing and billing and for administering the hauler accounts.

How easy is it for haulers to operate the system?

Carlson: The control system comes with a hauler station interface. Haulers see a large human-machine interface where they just follow the directions.

What system capacities are available?

Galanty: The SPIRALIFT SR30 has a capacity of 400 gpm when handling septage. A 4,000-gallon truck can get in and out in about 10 minutes.

What is involved in getting the system installed and operating?

Galanty: It doesn’t require a great deal of site work. The customer may have to build a pad for it and make sure it’s appropriately located relative to the road for the trucks. They need an electrician to wire it up, and they need to pipe the discharge to where it needs to go.