Case studies

Controlling Manganese & Ammonia Levels in Drinking Water

Drinking Water Aeration in Saint-Pie with OctoAir-10 Diffuser
OctoAir-10 aeration diffuser to control manganese and ammonia levels in drinking water
  • Drinking Water Aeration in Saint-Pie with OctoAir-10 Diffuser
  • OctoAir-10 aeration diffuser to control manganese and ammonia levels in drinking water
Ville de Saint-Pie

Town of Saint-Pie

Town of Saint-Pie, Quebec

The town of Saint-Pie has a water system fed by an 11.7 acre reservoir on the top of Mont Yamaska. This reservoir was monitored but left unaerated until 2007 when the decision was made to install a CanadianAir Diffusion System with an OctoAir-10 diffuser and a 3/4HP compressor from CanadianPond.ca to aid in controlling the release of metals such as manganese as well as the release of ammonia into drinking water. For reference, Health Canada suggests that manganese levels over 0.15 mg/L may lead to unfavorable drinking water taste, damage to plumbing fixtures and the potential for bacterial growth within the drinking water. The recorded data show a significant decrease in both manganese and ammonia levels since this time with manganese levels rarely surpassing the suggested upper limit of 0.15 mg/L. The reduction of total manganese is seen in figure 1.

Manganese Levels. Red bar marks the introduction of the aeration systemFigure 1: Total Manganese Levels from 2004 to 2013. The red bar marks the introduction of the aeration system

This decrease was made possible through the decrease of redox potential through the injection of dissolved oxygen into the water column. Both manganese and ammonia are important indicators of redox potential in sediments as they become soluble at lower redox potentials than substances such as iron and sulfates. These substances have even higher potentials to reduce drinking water quality and plumbing integrity. Higher redox potentials are equivalent to lower drinking water quality so it was imperative that aeration be used to control the situation.

Due to a lower chance of microbial activity and therefore reduction processes during the winter months, the aeration system was turned off. On December 18, 2009 manganese levels in the reservoir began to rise exponentially. This level reached its peak of 0.106 mg/L on December 29, 2009. On this day the aeration system was turned on for the first time during the winter months. Within 20 hours the manganese levels returned to baseline levels preventing damage and ensuring the quality and safety of the drinking water for Saint-Pie. Figure 2 illustrates this event.

Manganese levels. Black line indicates when aeration system was turned on.

Figure 2: Manganese levels before and the 29th of December 2009. The black line indicates the date at which the aeration system was turned on.

In conclusion, the OctoAir-10 aeration system developed by CanadianPond.ca significantly lowered manganese and ammonia levels and therefore improved drinking water quality for the town of Saint-Pie.