Ultrasonic system lowers TSS and algae

To remove very high turbidity caused by varying sized algae, Anglian Water has chosen to install ultrasonic algae control systems in Alton Water reservoir.

Alton Water reservoir
Alton Water reservoir

Anglian Water’s Alton Water reservoir and treatment works can treat up to 10 million imperial gallons (42,000 m3) of water a day. Recently the water treatment works was at a high risk of a total-loss-of-water-supply event to 92,214 properties. Abnormal growth of algae during the summer months and an accumulation of suspended solids was causing severe stress to the filtration process, threatening the smooth functioning of the downstream plant.

Anglian Water scientists conducted water quality sampling to try to understand the water quality issues and solids present. The project team contacted LG Sonic to discuss the suitability of ultrasonic algae control. It is important that the ultrasound uses low-power frequencies and has an established safety record for fish, plants, and other aquatic life, and this was something the utility was glad to establish.

To remove very high turbidity caused by varying sized algae, Anglian Water chose to install 13 MPC-Buoy systems in the reservoir. The utility said the MPC-View monitoring system “made it far easier to see and identify what is happening in the reservoir.” The group said: “When required, LG Sonic will increase the power output to the ultrasonics, which helps reduce any sudden growth and assist with keeping algae and turbidity levels down in the reservoir. Since the installation of the MPC-Buoys and ultrasonic programme, we have started to see the benefits in the reduction of suspended solids coming into the works and a reduction in algae going through the works. The system suppresses the algae in the reservoir, which reduces the growth of the algae.”

Prior to the installation, the high turbidity levels meant Alton Water Treatment Works could only achieve an output of 36 Ml/d. Afterwards, Alton WTW can deliver – for the first time – the expected output of 42 Ml/d.