Quarry - water discharge

Due to a spell of heavy rain, the client’s quarry had badly flooded, and the bunds for various settlement areas had been washed away. Selwood was called in to provide a solution, paired with its sister company Siltbuster, to treat the water before discharging the flows into a local water
course.

The need to transport the flows 870m to the outfall while maintaining the 22 l/s duty flow requirement to stop the Siltbuster discharge tank from overflowing or running dry.

The client is used to havingdiesel pumps on site, however, this application raised concerns about the use of a diesel set up.

The distance to the outfall created over 70m of head.

After surveying the site, it was determined that Selwood could run a Flygt BS2201HT submersible pump, utilising the existing 4” pipework on site, and controlled via a variable speed drive (VSD). 

The pump was placed at the discharge point of the Siltbuster chemical treatment system and ran directly from the client’s own, on site 415V, 3-phase power supply.

1. The VSD meant the pumps could ramp up or down to ensure they maintain the 22 l/s duty flow
requirement.

2. The site would be running 24/7 until the quarry is drained so Selwood was concerned about the quantity of diesel used, the frequent HGV fuel deliveries and the increased risk of breakdown
or performance issues with diesel pumps running 24/7. Therefore, Selwood opted to install an electric set up, which long-term is much more efficient and robust.

3. The Flygt submersible pump was more than capable of overcoming
the 70m head.