With more than 25 years of service at the city of Newark, Ohio’s wastewater treatment plant (WWTP), Superintendent Darin Wise knows his site inside and out. He takes pride in running this busy and well-kept facility with an experienced team. Including in-house, online and offsite education, Newark WWTP’s staff undergo approximately 300 hours of training per year.
Built in 1948, the WWTP is one of the largest assets owned by the city of Newark, handling 2.86 billion gal of wastewater per year. The enduring facilities and equipment are a testament to its team’s continual preventive maintenance.
In 1988, the city successfully met its deadline to bring the system in line with new U.S. Environmental Protection Agency (EPA) treatment regulations. In doing so, it also significantly improved the water quality in the Licking River, enhancing its recreational potential and aquatic habitat.
In 1997, the WWTP installed a new ultraviolet (UV) treatment system, which disinfects the plant’s effluent and has eliminated the need to add tons of chemicals to the water during the summer season.
Two major capital improvement projects completed in 1999 and 2000 included construction of a new influent screen building for fine process screenings for final disposal and a new SCADA system that provides real-time data for greater accuracy and efficiency.
A decade ago, electrical switch gear and substation/septic receiving projects were completed, resulting in the introduction of a new piece of equipment. According to Newark’s maintenance team, 10 years later, this piece of equipment is still the most trouble-free piece of equipment on site.
“Until we were able to invest in a new septic acceptance facility, we had a pump station with a grinder that couldn’t best cope with rags and hair,” Wise said. “Debris, such as plastics, was also getting into our digesters and adversely affecting the quality of our biosolids.”
After various trial demonstrations, and with space at a premium at the Newark site, the WWTP chose a self-contained, fully automatic Raptor septage acceptance plant (SAP) made by Lakeside Equipment Corp. Columbus, Ohio-based Smith Environmental—a team of professionals representing manufacturers of water and wastewater process equipment in Ohio—managed the SAP’s purchase.
Designed with a heavy-duty, three-plane fine screen, the SAP has a rotating rake that passes through the full depth of the basket bars to remove debris from the screening area. The rotating rake deposits collected screenings into a central screw conveyor hopper that leads to a transport tube. Screenings are spray-washed in two stages to return organic materials to the liquid stream. The first wash is over the screen basket and the second takes place in the transport tube just before the compaction zone to wash organics into the flow stream. The stainless steel shafted screw conveyor transports washed screenings to a discharge chute, and when debris drops to the storage container, the total solids content is typically more than 40%, passing the EPA paint filter test.
“Lakeside gave us plenty of very good references,” Wise said. “And the fact that their unit was 4 ft smaller than other manufacturers made everything easier—and, as a bonus, more economic. Also, with other systems, there was a need to remove the brushes, so it all made sense.”
Around 2.75 million gal of septic waste from across Licking County are treated at the Newark WWTP every year, delivered by six to 25 trucks per day, depending on the season.
An operator control panel located on the outside of the building allows haulers to initiate the off-loading cycle, and an automated truck scale that uses a swipe card system allows drivers to weigh in and out, usually in 5 to 10 minutes. These steps occur without the need for employee interaction. A waste report is automatically generated into the billing software.
“When we began using the Lakeside SAP, we were using a rock trap, but it filled up too quickly, sometimes from just one load, so it wasn’t best servicing our purposes,” Wise said. “This is probably because of the gravel that’s used in this part of the world to make septic tanks, which tends to deteriorate, so [it] therefore gets sucked out during emptying. Working closely [with] Lakeside, we modified it to a 6-in. outlet on the bottom on the tank, and since then [we] suck the rocks out every fortnight as part of our plant’s continual preventive maintenance program.”
Here to Stay
“We thought that the rocks would bend the rake and the comb on the septage acceptance plant, but we’ve come to learn that they don’t hurt it,” Wise said. “We’ve only had to straighten things out twice, but we’ve had no real problems, which is very good going for 10 years. Lakeside’s Raptor has been an extremely reliable piece of equipment that has also given us the option of sending the treated wastewater to the head of the plant or directly to our digesters.
“I fully expect our stainless steel Lakeside septage acceptance plant to give us a good 20 years-plus of dependable duty,” he continued. “At Newark, we’re very proud of our long service records, and this enduring piece of Lakeside equipment is totally in keeping with the high standards we strive to achieve.”