PC-SEP24-PG08-09.1_Layout 1 16/09/2024 11:43 Page 8
SOLIDS PROCESSING
SCREENING UPGRADE IMPROVES SEPTAGE HANDLING
A Water Resource Recovery Facility is now handling septage more efficiently thanks to a Lakeside
Equipment installation
t a Water Resource Recovery Facility (WRRF), sewage overspill on the floor and over your head was never a good way to start your day.
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Septage brought in by haulers used to be dumped into a six-inch pipe that went directly into the city’s main influent line, perhaps inevitably, (around once per month) backing up the old bar screen and washer compactor, creating an overspill. Meanwhile, due to abrasive grit, leaks - sometimes in the form of small waterfalls, would occur in pipes above the facility’s old garage/service building, showering unsuspecting staff with the less than pleasant contents of wastewater. Now, thankfully, the operators have much better starts to their day as a result of a three and half year, two-phase upgrade. Like all treatment facilities, challenges are just part of a working day, but new grit- removal equipment and Septage Acceptance Plant have removed those very unwelcome episodes at this busy plant. The after-effects of high-strength, sometimes shock-loading was certainly an ongoing issue, as it battled to strike a balance between taking in septage as a more than useful income, against the downside of the time/cost and labour to treat it. There was also the negative effect it would have on downstream equipment; not to mention potential violations.
Dan Widdel, Vice President of Lakeside Equipment Corporation (Bartlett, IL), commented: “We work closely with operators who work extremely hard to look after their facility, but sometimes, despite best endeavors, it can become a losing battle. In this particular case, the age of the equipment and the increasing flows with septage meant that maintenance has become very intensive.”
The City issued an RFP (Request For Proposal) for project design, which was awarded to a local engineering and environmental sciences business. Their design included two new grit channels, new vortex style grit removal equipment and a new septage acceptance plant. Lakeside Equipment Corporation was awarded the contract for this equipment through public bid from DuBois-Cooper Associates, which then
8 SEPTEMBER 2024 | PROCESS & CONTROL
brought together contractors and staff to fabricate and install Lakeside’s SpiraGrit Vortex Grit Removal System and Lakeside’s Raptor Septage Acceptance Plant (SAP). “Despite the tough applications,” continued Widdel, “our customers expect at least 20- years-plus service from our equipment, and with it, a big reduction in maintenance hours. The operators at this facility were confident with the recommendation that DuBois Cooper made, based on many successful Lakeside installations across North America.” Even with all the monitoring that is carried out to look at the incoming nutrient levels, there are always some unknowns with septage. Previously, the facility didn’t have a comprehensive metering system, and having load-amounts written on tickets that then had to be handled, was very time-consuming. That’s all changed now, with a card that is
assigned to each company, which is swiped at the facility, followed by entering a PIN to gain access. When the haulers are hooked up, they simply hit start and stop buttons to carry out their unloading. The new station provides administration capabilities to track and invoice customers, so the facility has freed up huge amounts of time. At the moment, haulers can gain access every day, from 7.30am to 4pm, but the plan is to make that 24/7. There’s been a small learning curve, going from manual to computerised operation, but the programming isn’t complicated, and the benefits are huge. Incoming septage is up by an average of 17% each year, and at the same time, the facility has reduced its maintenance costs by around 35%. The Lakeside septage and grit systems also help protect equipment further downstream in the process. Removing debris and inorganic solids from septage tanks, grease traps, sludge, leachate and industrial waste, the heart of the Lakeside Septage Acceptance Plant (SAP) is its Raptor Fine Screen, which compacts and dewaters the captured screenings to a solids content of 40 percent. The screen’s rotating rake teeth fully penetrate the cylindrical screen bars, which prevents plugging and blinding from grease and small debris. This allows for faster unloading times to generate more revenue. A new building to house the screening removal process has been very welcome indeed. Operators are no longer out in the elements, having to handle rags, grease, and messes. They are aware of what’s going on before entering the building, so, if ever required to shut the system down, can do so before entering and encountering hazards. In this very abrasive application, having two units means that the facility now has
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