A HUBER Technology Wastewater Case Study at Chippenham STW for Wessex Water

HUBER Technology were engaged in the design phase of this project prior to order in 2019 and were awarded the project in 2021 and finally commissioned in early 2022.

Project Profile

Chippenham STW serves the town of Chippenham and its surrounding areas with a PE of approximately 40,000 people. HUBER had been involved on and off in the site since the late 1990’s.

The site had 3 2M wide elevated inlet channels, 1 bypass channel and 2 Screen channels with 6mm INKA Step Screens that discharged into a launder; screenings were treated by a single screenings handling unit.

Pumped Flow to the inlet works was pumped via 3 Inlet pipes.

The INKA Step screens struggled with the increased flow to the site over the 20+ years since installation. They also struggled during storm conditions to deal with the large slugs of rag flushed down the pipes after a dry spell. This resulted in the inlet channels over topping onto the top level and the ground below the inlet works.

Since this project HUBER had been regularly engaged to look at improving the effectiveness of the inlet works and screenings handling plant to improve the screenings removal to lessen the impact on the downstream equipment, there were challenges surrounding this due to the site hydraulics and existing screens and screenings handling setup. Due to hydraulic constraints, the inlet works needed to be raised by 900mm, this improved the velocity of the flow through the works.

HUBER Technology Supplied:

•  2 x HUBER Escalator Screens EscaMax® V 5000x1652/6 60^o 6mm perforated plate screens.
•  2 x HUBER Screenings Wash Press WAP® L  6 screenings handling plant
•  1 x HUBER Launder Trough

Objective

The primary objective was to provide new 6mm inlet Duty/Asist screening to protect the downstream process from screenings and other debris and also provide similar Duty/Assist screenings handling plant to wash and compact the removed screenings.

Solution

Being our local treatment works, we had been involved in various aspects of the site since the late 1990’s we had plenty of knowledge of the existing inlet works and the problems it suffered with. By early engagement with Wessex Water meant we were able to be involved with the project from the outset.

Each screen supplied was required to handle a flow rate of 900 l/sec working on duty/assist basis with the subsequent screenings handling plant being able to handle 6m³/hr of screenings also working in Duty/Assist mode. A further challenge was the location of the screenings handling plant, to avoid blocking the access road around the site,  this required in the region of 25 metres of launder trough to transport the screenings.

The new inlet screenings solution has been found to be very effective.
 

“It was great to re-engage with Wessex Water to get our local treatment works upgraded. We were delighted to engage early to deal with the complex challenges of building this inlet works and to keep the works running during the installation period.We are confident that our design and the equipment supplied would provide the end user with a vast improved performance of the inlet works and downstream processes.”
 Adrian Heneghan – Area Manager