The thames river

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Conveying product

Sludges of differing densities and temperatures

Key specifications

Tailored pump solutions for the UK's second-largest sewage treatment plant

Built N300-36 transfer pumps in record time, measuring 11 m in length, weighing 7 tons

High-precision design:
Machined from a 1.7 ton piece
of tool steel with precision
down to 0.2 mm, the rotor
is 6 m in length and
weighs 0.7 tons

Full-service package

Cost savings

Minimal need for replacement parts

Short downtimes


Reduced labor costs

Pump type

Thames Water operates one of the UK's largest wastewater treatment plants in West London, which treats sewage for around 2.1 million residents. A plant of this size requires both pumps and service that is extraordinary. SEEPEX delivered both.


Originally built in the 1930s, the Mogden sewage treatment plant has undergone major expansions over the decades to keep up with exploding population growth. Operator Thames Water has now converted the large plant over to using SEEPEX pumps. The customer needed more than just equipment, requesting a sophisticated service package as well to ensure optimal operation.


This was no small challenge given the variety of sludges involved of differing densities and temperatures. SEEPEX had to precisely design every pump – ranging from the small metering pump for liquid polymers to the many transfer pumps for sludge treatment – for specific requirements. Pumps also had to be developed which were capable of moving 180 cubic meters of slurry to the sludge treatment facility 16 km away. Additionally, special measures were required to ensure smooth and efficient pump operation, reducing downtime and costs.


The extraordinary SEEPEX N300-36 transfer pumps were deployed, becoming milestones in technological development by being the biggest progressive cavity pumps in existence at that time in both length and weight.

We built the N300-36 in just 16 weeks. 30 employees from various departments were involved, and everyone contributed their knowledge. That's how we got the job done in record time!
Jörg Brune
Engineering, Manager General Research, SEEPEX GmbH

Since commissioning, SEEPEX has performed full-service monthly inspection and maintenance of the pumps, checking dry running, overpressure, wear, driving power and efficiency. The key is performing preventive maintenance, on site and the same day if necessary, before any breakdowns can occur.

The success is evident, as pump downtimes at the sewage plant have been drastically reduced. SEEPEX UK is now responsible for maintaining a total of 68 progressive cavity pumps and macerators at Thames Water facilities and at the neighboring Iver South sewage treatment plant located in Slough.


SEEPEX not only supplies pumps of nearly any dimension: the company is also highly service oriented. Providing full service significantly reduces downtime and repair/replacement expenses. 

The bottom line: Substantially lower lifecycle costs.

SEEPEX rotor 15 degree angle on black background
SEEPEX rotor horizontal on black background
SEEPEX BN 17-6LS pump horizontal on black background