Pumping wet wipes at a municipal wastewater treatment facility
Wastecorp employees read a story posted on YAHOO! from Yahoo and Thames Water’s Website (Thames water is responsible for sewer maintenance in London, England) about a “fatberg” comprised of cooking oil, wet wipes and more which was roughly the size of a Boeing 747. In our weekly global meeting, many on the call contributed to the discussion because in almost every pump markets globally, our customers have to manage either issues relating to cooking oil or solids in the sewer system. The manufacturers of wet wipes worldwide have said that they are researching and developing new products that will help to reduce the clumping issue. But the primary contributor to this problem is not the wet wipes; no one should be dumping cooking oil down the drain – ever. As the YAHOO! article says, when you dump hot cooking oil down the drain into the cold sewer system the fat congeals and clings to anything including the wipes, toilet paper or other solids.
Related: Thames Water Press Release about the “Fatberg”
Here is North America; municipal wastewater treatment operators routinely voice their concerns to us about the use of wet pipes by the general public and then flushing them down the toilet. “Do you guys make a pump that can better handle the wet wipes” is a question Wastecorp frequently receives at our sludge pump call centers. Jim K. from Winston Salem North Carolina tells it like it is:
“ All these wet wipes that come into our mid-size WWTP are wreaking havoc on our pumps. We use rotary lobe pumps and progressive cavity pumps and they just clog them causing them to fail and then thousands worth of damage. We need to go a different route. Our city engineer was looking at Wastecorp’s website and suggested we ask about either your plunger pump or double disc pump options.” We need some guidance here please.” Jim K. – Winston Salem, NC
Well Jim, the rotary lobe and progressive cavity companies will sell you the same story: go with our pumps – they’re new. They are leaving out an important fact most lobe and progressive cavity pumps have been around just as long as plunger pumps, (+- 75 years) and most of lobe and progressive cavity pumps don’t do a good job of handling solids. When it comes to plunger pumps, they are a lot less likely to clog. The check balls and pistons move sludge and wet wipes and send them on their way. You should also consider a screen and a grinder in your WWTP process, but having a pump more capable of handling solids will go along way.
Jim, like your city engineer said, many WWTP’s your size have selected either a plunger pump or a double disc pump to manage these wet wipes. We see a lot of facilities your size going the route of the Sludge Master® PE-941 SSIII or our Sludge Pro® 4DDWP™ Double Disc Pump Series. Unless your facility has an endless budget to keep replacing rotors, stators and bearings your facility would be wise to consider other pump options. More info can be found at www.wastecorp.com
Related: Waste oil pumps and containment systems
Sewer Overflow Problem in Modern Cities
When we visit our customers at wastewater treatment plants and ask operators “what are your facility’s most pressing concerns?”, the answers we most frequently hear are ever tightening budget constraints and dealing with aging infrastructure. And this concern echoes not only in the United States, but in many parts of the world. So this is nothing new right? City budget problems have existed for years. Well, the problem is that aging infrastructure designed to treat sewage may not be equipped for rising urban populations and shrinking green space to protect us from harmful bacteria and other negative health effects.
A New York Times article highlights these concerns. For example, more than 9400 of 25000 American sewage systems have reported violating environmental laws by dumping partially treated human waste, chemicals and other hazardous materials in lakes, rivers and waterways. “This may contribute to more than 20 million illnesses each year in the U.S. alone from drinking water contaminated with bacteria and other pathogens that spread from untreated waste.”* When sewage systems overflow they may be discharged close to water intake points or public beaches which is of major concern.*
When Wastecorp designed the Sludge Pro Double Disc Pump we set out with the goal to engineer the easiest to service sewage pump available to engineers and WWTP end users. One common request from the engineering community was that an operator or maintenance person would never have to crawl under a double disc pump with a casting hanging overhead and the potential for sewage to leak over the operator. When you think about – why would anyone design a pump like that? Our answer is that you would have to ask the competitor because Wastecorp would not.
Servicing a double disc pump
The video below shows how to change the trunnion on a Sludge Pro double disc pump. As you can see most of the maintenance is done with the operator standing up and most components visible to the operator. Continue reading
Orange County Sewage Pumps
Orange county is home to dozens of resorts, hotels and theme parks which generate tens of millions of gallons of wastewater that needs to be treated every year. When an Orlando, Florida renewable energy company earned a multiyear contract to accept waste from local resorts and theme parks, they needed severe duty pumps to transfer thick slurries and solids.
The details of the project called on the requirement of pumps to transfer ground up seafood shells, grease trap waste, utensils, animal renderings, wastewater and more. In this application, the waste is unloaded from a tanker into a waste pit. The waste is then transferred to a conveyor system which then separates most of the foreign objects like utensils, large solids, plastic bags and more. The remaining waste is sent through the Sludge Master plunger pump and then to the digesters of the wastewater treatment plant. With millions of people visiting Orlando resorts and theme parks every year, this amounts to a lot of waste, as tanker trucks deliver new loads of slurry like liquid waste around the clock. Continue reading
Primary Sludge Pump Options
Primary sludge pumps are typically used in municipal Wastewater treatment facilities to transfer digested sewage and sludge. This is a broad pump category that encompasses positive displacement pumps to pump sludge in ranges usually up to about 500 GPM. The choices of pumps vary from double diaphragm pumps, plunger pumps, double disc pumps, rotary lobe pumps, progressive cavity pumps and more.
In todays pump marketplace, there are generally two schools that operators and consulting engineers follow when specifying primary sludge pumps. The first option is Continue reading