Hydria Water purifies Hong Kong’s harbour

The Stonecutters Island Sewage Treatment Works in Hong Kong is a much-discussed project that has attracted a great deal of excitement, and to which Hydria Water delivered Mellegård & Naij’s products for several years. Soon, the last shipment to the sewage treatment works will leave our premises in Skövde, Sweden.

The Stonecutters Island Sewage Treatment Works is one of the world’s largest, treating roughly 2.5 million cubic metres of water every day from roughly 5.7 million people. This, together with the Changi Water Reclamation Plant in Singapore, is some of the largest project Hydria Water has ever undertaken.– It means a great deal to us to be contributing to such a large and amazing project that everyone in the industry is talking about. Our machines have been installed throughout the inlet and in the subsequent screenings handling process, and we will soon complete our last delivery, Rikard Karlsson at Hydria Water says.

– We have delivered eight Cross Screen XS mechanical-step type screens and eight conveyors. As the sewage treatment works is intended to handle large flows the channels are three metres deep, which meant that we had to build a mechanical step-type screen with a discharge height of 4.5 metres – which is among the highest we have ever delivered. The dimensions of the conveyors were between 7.5 and 15 metres, Rikard explains.

Over the course of the project, documentation and photography during manufacturing have been very important. This is particularly true prior to shipping, which takes 45 days from harbour to harbour.

– We sent a first test shipment. The client was satisfied with our products, considered them to be of high quality and wanted more of our machines, which of course felt very good. We have visited the site several times, among other times during the test run, when the flow was tripled so as to really test our machines!

The Stonecutters Island Sewage Treatment Works has undergone upgrades and alterations in several steps so as to achieve a cleaner environment in Victoria Harbour.

Step 1
During the first step, 23 kilometres of tunnels were dug underground in order to connect the seven water reclamation plants of Kowloon, Tsing Yi, Kwai Chung, Tseung Kwan O, and eastern Hong Kong Island to the Stonecutters Island Sewage Treatment Works, with the goal of purifying 75% of the wastewater in the harbour area on Stonecutters Island.

Step 2
During Step 2, eight water reclamation plants from northern to southwestern Hong Kong Island were connected, via 21 kilometres of underwater tunnels beneath the harbour basin, to Stonecutters Island Sewage Treatment Works, which at the same time was expanded and upgraded to handle the increased flow. Since of the completion of this step, 100% of the wastewater from the area around the harbour has been treated at the Stonecutters Island Sewage Treatment Works.