Project Description

The Problem

One of the UK Water companies contacted Willacy to ask if we could help them clean a sludge storage tank that had over the years filled with very fine, very heavy silts that had become contaminated with a hazardous substance. The tank was 10 metres high and 10 metres in diameter and contained approximately 1200 cubic meters of sludge that was only semi-mobile. The client wanted a turnkey solution which included the disposal of the hazardous waste.

Case Study UK Water Company Tank Cleaning

Above: Our portable centrifuge system and access platforms.

Case Study UK Water Company Tank Cleaning

Above: Our storage tank in the background and our portable centrifuge system.

The Willacy Solution

Upon an agreed start date we deployed our team of tank cleaning experts with one of our mobile centrifuge systems. Using high pressure jetters from the access platform, the sludge was liquefied sufficiently to allow our hydraulically-operated reversible Molex pump to transfer the sludge out and into one of our portable sludge containers where it would be kept agitated.

From here it was dosed with polymer and fed into one of our portable centrifuge systems. This de-watered the sludge into a solid ‘cake’ which meant the volume taken off-site and vehicle movements were kept to a minimum. The use of tankers was also eliminated.

The clean water was fed back into the works inlet and the ‘cake’ was transferred into bulk tippers, where it was removed to a treatment plant. The whole project was carried out well within the time allowed and under budget.

Case Study UK Water Company Tank Cleaning

Above: The sludge looking down into the tank from the single access platform.

Case Study UK Water Company Tank Cleaning

Above: The ‘cake’ was taken off site to a licensed disposal treatment plant.

Case Study UK Water Company Tank Cleaning

Above: The cleaned water was returned to the sewage works inlet.