Hastings (Public Water Supply) - Case Study
1 August 2011
The Brede public water supply site near Hastings is a complex system of tunnels, wells and adits. At over 100 years of age, the facility was in desperate need of rehabilitation due to the build up of iron oxide residues. The facility comprises 3 wells with a diameter of 3m and 80m in depth. 400m and 20m long tunnels and adits connect the wells. Water volume is approximately 1,726,000 litres.
The products were injected into the system and a recycling loop achieved between two of the main wells. The treatment liquid was cycled through the adits for a period of days, followed by clearance pumping which took 5 days due to the size and scope of the facility. In normal wells and bores, this can be accomplished in just a few hours.
Pumped groundwater samples were taken throughout the rehabilitation project. After 5 days of clearance pumping, the raw water was returned to background values. A GCMS scan, taken after clearance pumping, showed all iron oxide residues had been removed, and the adits cleared of the IRB biofilm.