This new site had bottom and topsealing systems, and a leachate treatment system incorporating biological pretreatment using ultrafiltration and reverse osmosis for leachate concentration.
To overcome the shortcomings of the existing system, North of Scotland Water required improvements to be made in both drinking water quality and the available raw water quantity.
ARP decided to expand production by approximately 50% over a two year period. Two competitive offers for a third large triple effect evaporator were considered in conjunction with PCI’s reverse osmosis system.
As with many Highland burn sources, the raw water at Achnasheen is both variable in quality and quantity, leading to peaks of colour and turbidity, particularly when the burn is in spate.
The average COD of this effluent is approximately 10gm/litre, therefore a total of about 3 tonnes of COD is produced every hour. Due to stricter legislation, and the need to be “green”, it became necessary for Stora Nymölla to obtain the “Swan” mark for their products.