The microbial quality of raw water, drinking water and recreational waters has for long been viewed as essential to monitor closely. Despite the advances, waterborne pathogens stil...
The microbial quality of raw water, drinking water and recreational waters has for long been viewed as essential to monitor closely. Despite the advances, waterborne pathogens still pose a threat to public health and most of the disease-causing organisms originate from contaminated drinking water. Developed countries have managed to enhance the treatment and prevent agricultural effluents and sewage from contaminating rivers and reservoirs used as water sources. In developing countries however the situation is more severe, with the World Health Organization reporting that the estimated number of gastrointestinal disease cases lies on more than 26 billion a year. The majority of pathogens that travel through drinking water or recreational waters and cause disease in humans has fecal origin. The feces that are most known to carry potentially pathogenic substances come from human beings, other mammals and birds. The different bacteria, viruses and other parasites that can pose a health risk have long been identified, however testing for all of them is way too time and cost consuming. A consensus in the water industry has been that searching for a few groups of bacteria that work as indicators of fecal pollution should be sufficient in order to raise the alarm. Coliforms, fecal coliforms and E. coli are all enterobacteria that primarily colonize the colon and are found present in all fecal samples. Additionally these organisms are relatively easy to test for. The standard methods depend on sample filtering and subsequent growth on culture media. They also rely on a laboratory technician to examine the samples after the 24 hour incubation period, making the whole testing regime take 24-48 hours until an answer is provided. Water authorities require that the water utilities maintain a certain frequency of testing. The challenge lies in that fecal pollution events can hit randomly and therefore not all incidents are recorded by the fixed testing scheme. In order to increase testing frequency the amount of manual labor would also need to be increased. As an alternative to that and as a supplement to the testing already required by the authorities a fully automated on-line instrument is an option. This type of monitoring system can be placed on the water source to take samples automatically, analyze them and after a shorter time than traditional methods send results to operator. Colifast AS introduced its fully automated analyzers and unique cultivation media formulas to the water industry more than 20 years ago. The Colifast technology is based on automation of methods equal to standard methods used by accredited laboratories. For decades the instruments have been monitoring the bacterial quality of raw water, rivers, drinking water and distribution networks all over the world. With a unique product range and in-house production the user is guaranteed a high-quality instrument manufactured by skilled Colifast personnel in Norway. The Colifast ALARM is designed for drinking water analysis and measures presence/absence of E. coli, fecal and total coliforms (as well as Pseudomonas aeruginosa in 100 mL water samples. Analysis time is 6-15 hours and the result is sent to user via PLC, LAN or SMS, normally following a diel test frequency. Every third week the growth medium needs to be replaced. The Colifast ALARM has a special feature that gives the user the opportunity to take out an extra sample simultaneously as the one for analysis. The user can fetch the bottle from the cooler and take it to the laboratory for further investigation if an incident has occurred. The CALM (Colifast At-Line Monitor system is based on the same principal but performs more advanced testing of the water samples and therefore can give a quantitative number of bacteria. It is typically used for environmental monitoring and raw water control. Analysis time is 2-12 hours and growth media for detecting E. coli, fecal coliforms, total coliforms and Pseudomonas aeruginosa is supplied in prefilled ready-to-use multiwell trays. Both Colifast ALARM and the CALM system have been verified through third party testing abroad. The US EPA Environmental Technology Verification Program verified the Colifast ALARM while three European institutes and utilities coordinated by an EU project verified the performance of the CALM system compared to the ISO reference methods.