Chopper pumps cut costly cloth clogging issues

Here, we look at three examples in the United Kingdom and the United States of how Landia chopper pumps are providing a solution to clogging, ensuring wastewater flows freely, preventing costly disruption.

Until Mitchell, Lewis & Staver introduced a Landia Chopper Pump, sewage
systems in the town of Declo were under siege from wet wipes.

Raw wastewater running through a pumping station in Declo, Idaho, typically contains less than 1% solids but despite this, clogging and blockages were occurring.

The problem for the existing four inch pump was that rags wound themselves around the standard, ‘non-clogging’ impeller. “The curse of wet wipes and the like is all too common problem for lift station pumps these days,” explained Ty Collins from pump, motor and drives distributor Mitchell, Lewis & Staver.

Mr Collins’ solution was to install a dry-pit Landia chopper pump in a bid to reduce the costly downtime and maintenance costs caused by the blockages. “Landia’s chopper pump has a hardened external knife blade system, which very importantly, chops up solids and any stringy material prior to them entering the impeller,” he added.

Rural towns still need decent pumping equipment to cope with sewer abuse. 

Landia also designed and built a base/suction elbow to match the existing suction and discharge piping height and since its installation, the municipality of Declo has reported neither clogging issues nor downtime with the Landia chopper pump.

The same situation was occurring at the East Hyde sewage treatment works near Luton, UK where operator Thames Water was looking to improve its handling of stormwater. The solution came in the form of a six inch Landia MPTK-I 150 series Chopper pump.

Sewer abuse

“We have a lot of issues with wet wipes and rags being put into our sewers which block our pumps,” said Thames Water’s Phil Merridan. “We’ve been forced to install this apparatus due to the worsening problem of sewer abuse, which is people putting anything other than human waste and toilet paper down the drains.

“Food fat and wet wipes are the prime sewer abuse offenders. Fat goes down the drain when it’s warm, but when it gets to our sewers it causes blockages. Wet wipes, despite labelling which says they are ‘flushable’, should never be flushed. They cling to fat causing environmentally damaging blockages and they block up our treatment works.

“Landia’s pumps will help deal with this problem, but it is something that should really be tackled at source by everyone following our sewer motto: bin it – don’t block it”. Following the successful installation, Thames Water has since purchased two more of the Landia units, which are especially suited for the pumping of wastewater and sludge with coarse solids.

Meanwhile, a major university in Washington State, United States was forced to take action after it came close to sewage. Again help came in the form of a Landia chopper pump supplied by Mitchell, Lewis & Staver.

Costly maintenance

The near-miss overflows at the university were being caused by the continuous plugging of an existing sewage pump, also resulting in downtime and constant, costly maintenance.

“Standard pumps can deal with standard sewage, but they are no match for the stringy, tear-resistant synthetic fibres of products such as wet wipes,” said Ty Collins from Mitchell, Lewis & Staver. Mitchell Lewis & Staver reviewed application data and changes in the waste stream with the campus facilities manager, opting for a submersible chopper pump that would be capable of actually cutting up the fibrous and stringy materials to the point that they would be pumpable.

“We specified a Landia chopper pump because of its proven, dual-action cutting mechanism and stationary hardened knife system,” said Mr Collins. “These knives chop and cut the materials prior to them entering the impeller. We’ve seen that other chopper pumps use the impeller itself as part of the cutting mechanism, but the Landia design allows for a far more efficient impeller system, whilst still passing whatever nominal solids remain.

“Since the installation of the Landia chopper pump, the results at the university speak for themselves: Zero clogging. Zero maintenance”.