The challenge

In a water treatment plant in Killaloe in the province of Ontario, Canada, chlorine was used as disinfectant for many years. However, by using chlorine, toxic by-products (trihalomethanes (THMs)) are formed when chlorine reacts with organic matter present in the water. Trihalomethanes are carcinogenic and therefore, the Ministry of the Environment (MOE) dictated that the level of THMs in drinking water should not exceed 100 μg/l.

When exceeding the legislated limit of 100 μg/l, the drinking water system was flushed and the water in the clear wells was renewed. This was an effective solution, but it was temporally and it had a couple of disadvantages. This method was inefficient, because large quantities of treated water was wasted. This method was also very costly due to the use of chemicals and electricity for waste water treatment.

Our solution

The Ontario Clean Water Agency (OCWA) proposed a solution based on the Huwa-San technology.  The main goal was to eliminate the use of chlorine, and consequently to minimise the production of carcinogenic trihalomethanes.

The product that was introduced was Huwa-San TR-25 because it is a colorless, tasteless and odorless disinfectant. This in contrast with a water supply system treated with chlorine, which adds an unpleasant taste and irritant odour to the water that customers dislike and complain about.

This Water Treatment Plant in Killaloe had also a problem with biofilm/biofouling on the pipes. These are perfect hiding places for bacteria and other viruses and pathogens, which contaminate the water and have a detrimental effect on the water quality . By dosing Huwa-San TR-25 to the pipe systems, the biofilm was completely removed, resulting in an improved bacteriological water quality.

Huwa-San TR-25 is currently available in Canada via Arbourdale.

OCWA’s director, Andy Valickis, says that Huwa-San is an excellent alternative for chlorine as drinking water disinfectant. He states that Huwa-San provides a solution for all water treatment systems which have problems with the formation of THMs and other toxic by-products, due to the use of chlorine as disinfectant.