Sludge processing plant design worth the effort

Sludge processing plant design worth the effort
Before the first building was constructed, Tim Frank Septic Tank Cleaning Company housed the plate-and-fram press in a trailer. (Photos courtesy of Tom Frank)

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Tim Frank bought Septic Tank Cleaning Company in 1966, and at that time land application was the way of disposal. However, the company was located in the snowbelt of northeast Ohio, and this made land application in the winter a challenge. The nearest sewage treatment plant was more than 90 minutes away, so Frank decided to land apply on his own farm. This caused problems in the winter, so with the help of the Ohio State University Extension office, Frank installed a holding lagoon on his land. The university saw his eagerness to learn and his desire to improve operations, and invited him to be involved with the rule advisory board and the Extension advisory board to help policymakers create rules beneficial to pumpers and homeowners.

In the 1990s, the U.S. Environmental Protection Agency Part 503 Biosolids rule led to the organization of several national groups representing industry professionals. The National Association of Wastewater Technicians asked Frank to be involved in the startup of the Ohio group. He connected with people who were dewatering septage and land applying the cake. With growing population around his facility, increased septic collection and the pending new rules, it was evident that some type of processing was necessary.

Field trips and production
Frank and his team visited septage dewatering facilities in Philadelphia. After several trips, they obtained a used plate-and-frame press to get the ball rolling. The finished product was a 50-cubic-foot press with approximately 48 plates that would reach capacity in about four hours. The press was housed in a semi-trailer because it was less expensive than constructing a building. Two large pressure-rated tanks, a holding tank for mixing without disturbing the lagoons, and a tank for mixing lime and measuring batches sat next to the trailer.

The tanks were designed for outside use, and beneath the valve end a 2-foot-deep by 8-foot-wide trough returned spills to the first lagoon. Underneath the press a conveyor belt gathered sludge and sent it down a chute to another conveyor belt, which transported the dried cake to a storage building. The conveyor belts were converted from old grain elevators. Around the time the press was purchased, the company decided not to accept grease trap waste in order to continue land applying.

They used high calcium quicklime to condition the septage, reducing odor and complying with regulations. Pressing occurred from mid-spring to fall, and the company had to be careful about freezing. Most of the sludge was still land applied, but at times, it was sent to the landfill when it was too wet. Land applying meant fewer trips to the fields, and it looked more like a farmer spreading manure than a pumper spreading septage, which eased public scrutiny. With no discharge permit, the company had to spray water over fields with a hard hose traveler. 

Rules and regulations
When the 503 rule went into effect, the company understood that aerated waste retrieved from semi-public sewage treatment systems up to 25,000 gpd would be considered septage. At some point this was changed or reinterpreted, so aerated waste mixed with septage would be classified as sewage sludge and fall under a more stringent rule. They continued to haul sludge to larger public facilities until those facilities felt the effects of the 503 rule and could no longer accept aerated waste.

In 1995, Frank decided to bury holding tanks, with a well to keep groundwater away and to monitor leaks. From time to time, the company would empty and clean tanks, then press the leftover sludge. Effluent from the press would move through the lagoons, and the cake would be hauled to the landfill, keeping it separate from the other septage, allowing it to be applied under the less stringent rule.

Effluent management
The company continued pursuing a more efficient way of handling effluent and discharging water. They found out there were no receiving streams large enough to discharge the desired 25,000 gpd flow. They decided to construct wetlands to further treat the effluent from the press and lagoons, and later irrigate it onto farmland. Year-round processing was also put into effect.

Frank bought 50 acres and erected a building around the tanks, a mezzanine for the plate-and-frame press, and the press itself. The cake fell directly into a roll-off container, eliminating the need for conveyer belts.

During construction, Frank began applying for a permit to install from the Ohio EPA. He was issued the permit, which allowed for four man-made wetlands, a 2.5-million-gallon holding pond for inclement weather, and 24 acres of spray irrigation. It took time to find an irrigation supplier that understood what they were trying to do and was willing to give them what they needed. They settled on 15 spray heads with a 200-foot radius with room for expansion.

The wetlands took several years to finish, and they had to disc the fields and remove large rocks before planting. They planted corn the first few years to allow leftover roots to decay, then moved to hay with the hope of having someone cut and bale it. This did not work, as it was difficult to align farmers’ and companies’ schedules.

Incoming processing
The company then needed a better screening option for incoming septage, which had been screened through 3/4-inch expanded metal. That filtered bigger items, but was time consuming to clean, so Frank purchased a Maximizer automated screen from Lely Manufacturing. A bar screen in a tank removed larger items, and the smaller items were screened through the Maximizer. This sped up dumping time and allowed for more time servicing customers.

In 2000, they purchased another 50-cubic-foot used, automated press with 98 plates that produced a thin cake. This made pressing easier because they didn’t have to move the press plates by hand, and it took less time to fill with thinner cake. It started getting difficult to align timetables with farmers for land application, so the company began shipping most cake to the landfill.

Learning experiences
In ­­­­­­­­2005, the company hosted a field trip for National Onsite Wastewater Recycling Association members at the facility to show septage facilities could be built and operated responsibly. The next year they hosted the first NAWT symposium on waste treatment to show how the facilities were put together.

In December 2007, a machine parked next to the building caught fire, and the building burned to the ground. This provided a learning experience about reviewing insurance plans annually, and about determining which equipment is stored in what buildings. The cleanup took most of the remaining winter, and by spring a new building was constructed in the same footprint as the old building.

After attending several symposiums and conventions, Tim Frank Septic Cleaning Company decided to go with a more automated process, purchasing a screw press from FKC Co. Ltd. While the former plate-and-frame press was a batch process that took approximately four hours, the screw press operates continuously runs with minimal operator assistance. The screw press went online in June 2008 as Tim stepped down from day-to-day operations and his son Tom, took over.

In summer 2011, the company came across an article about Aloterra Energy looking for companies willing to grow Giant Miscanthus grass. Tim Frank Septic Cleaning Company saw the grass, a renewable energy source for manufacturing paper products, as a unique opportunity. Miscanthus also fit into the spraying schedule, as it is only planted every 10 to 15 years, is harvested in the winter, and allows for continual spraying.

Future plans
The next step will be to research and add a process to achieve a Class A product. The company would like to make beneficial reuse less complicated and get away from the landfill.

Creating a private sludge processing plant was never easy. Each new piece of equipment or process added a learning curve and adjustment time. Other obstacles included different levels of government. For example, a local county where the company pumped solved an issue of illegal waste disposal by requiring all septage go to a publicly owned treatment facility.

To continue serving customers in the county, Tim Frank Septic Cleaning Company made a video about its processes and filed for and was awarded a variance to haul septage to its own treatment facility.

In August 2012, an NPDES permit went into effect to monitor the volume and quality of the water and sludge the company landfills or beneficially reuses. The permit took some getting used to, especially the weekly tests and data gathering required by the EPA.

Public relations
The treatment facility has been beneficial and has provided good networking opportunities. The company can tell customers they handle what they pump, and to some people these environmentally sound practices are important. Another way they were able to inform people about the facility and processes was having a party at the treatment facility.

The company organized a millennium party in 1999 at the building that housed the plate-and-frame press. More than 150 people showed up and danced the night away next to containers full of sludge. The company gained many supporters because guests realized there was little to no odor.

Being involved in the industry has created many acquaintances over the years who have been valuable sources of information and knowledge. Tim Frank Septic Tank Cleaning Company is servicing the fourth generation of some of its customers, proving it has all been worth it. 

Tim Frank Septic Tank Cleaning Co. won the 1998 Special National Award for Outstanding Septage Gathering, Processing, and Utilization Services & National Support of Environmentally Sound Compliant Practices from the U.S. EPA.


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