Site Description
Originally opened in 1957 Glenlatterach Reservoir is located near Elgin in Scotland. The reservoir functions as a water supply to the local area. With a surface area of 40.7 ha, the reservoir was formed from an impounded river valley.
Management Issues
The reservoir displayed elevated manganese concentrations which required additional water treatment and associated costs at the local water treatment works. In most temperate, stratified reservoirs, elevated manganese concentrations are primary associated with internal loading from bottom sediments under low-oxygen conditions although there are numerous factors that also contribute towards elevated manganese in water.
The Solution
A custom engineering aeration system was design and installed in Glenlatterach late spring of 2026. The system comprises of 4(no) diffusers with an overall mixing area based on 5x the water depth. The system designed needed to function to satisfy the following customer requirements.
1) Improve overall water quality by maintaining dissolved oxygen concentrations throughout the water column and across the water / sediment interface.
2) To reduce concentrations of manganese within the abstracted water supply.
When tackling elevated manganese levels in waterbodies, using diffuser-based aeration and mixing systems, there are two primary approaches we can take for manganese water treatment.
Firstly, artificial destratification which focuses on preventing the occurrence of stratification, particularly in the spring months. By maintaining vertical circulation and oxygenation, destratification addresses the root causes of anoxia and internal loading and elevated metals in waterbodies.
Secondly, hypolimnetic oxygenation which seeks to oxygenate bottom waters while preserving thermal stratification. This approach is particularly useful where ecological constraints require maintenance of cold water habitat or where intake depth makes vertical mixing undesirable. The approach taken in this project was artificial destratification.
Due to the isolated location of the reservoir, the available power supply was limited. To ensure efficient mixing, careful consideration of the positioning and output of the diffusers as well as the compressor configuration were taken. This approach ensures that the reservoir operates optimally despite the constraints.