Control of Manganese and Ammonia in Drinking Water
The Town of Saint-Pie has a water system supplied by an 11.7-acre (4.7 ha) reservoir located at the top of Mount-Yamaska in the province of Quebec. This reservoir was well monitored for years but wasn’t aerated and mixed until 2007. That was when the decision was made to install a complete Bubble Tubing® system with an OctoAir-10 diffuser to help control the release of metals such as manganese and ammonia in drinking water. Health Canada states that “at concentrations greater than 0.15 mg / L, manganese stains plumbing fixtures and fabrics; moreover, in high concentrations, it gives bad taste to drinks. Like iron, it can cause problems in distribution networks by promoting the growth of micro-organisms. Since the installation of the aeration system, recorded data shows a significant decrease in the level of manganese and ammonia in the Saint-Pie reservoir. The level of manganese now rarely exceeds the suggested upper limit of 0.15 mg / L.
This improvement was made possible by the reduction of the redox potential by injecting dissolved oxygen into the water column. Manganese and ammonia are important indicators of redox potential in sediment because they become soluble at lower redox potentials than substances such as iron and sulphates. These substances have an even greater potential to reduce the quality of drinking water and the integrity of plumbing. Higher redox potentials are associated with poor drinking water quality so it was imperative that aeration be used to control the situation. In simple terms, manganese appeared when the highly stratified lake ran out of oxygen in its depth. Most drinking reservoirs go through the same issues in absence of aeration.
Due to the reduction in microbial activity and the reduction processes during the winter months, the aeration system deemed to be less essential and was turned off. On December 18, 2009, the level of manganese in the reservoir began to increase exponentially. The highest level of 0.106 mg / L was reached on December 29, 2009 when the aeration system was finally turned back on. Within 20 hours, the manganese level returned to baseline, preventing damage and ensuring the healthy quality of Saint-Pie’s drinking water.
In conclusion, the OctoAir-10 aeration system used by Bubble Tubing® and developed by Canadianpond.ca Products Limited significantly reduces manganese and ammonia levels and improves the quality of drinking water in the City of Saint-Pie. This system has been in operation since 2007 and has saved a lot of money in chemical treatments and has also been responsible for the bio-dredging of the reservoir which has seen a massive amount of reduction of its accumulated organic sediments which were responsible for the worsening conditions over time. The last time the lake was dredged was in 1980. The town has gained many years of extended life since adopting Canadianpond’s technologies.