Online microbial water analysis – ALARM

Colifast ALARM Process monitoring - ultra filtration water treatment

Colifast ALARM - Rapid, on-line microbial water analysis

Colifast ALARM™ is an online instrument for detection of indicator bacteria in drinking water by using the patented Colifast technology. 100 mL water samples are automatically collected at programmed intervals and analysed for total coliforms, thermotolerant coliforms or E. coli. In addition to performing rapid, online microbial water analysis the Colifast ALARM measures water turbidity. The system can automatically send results to the control room / operators via LAN, digital signals or by mobile phone network (SMS). The system can detect down to 1 cfu/100 mL, and results are obtained within 6-14/15 hours.

  • 100 ml Presence/Absence test
  • 6 - 15 hours
  • Turbidity
  • Runs 21 days unattended
  • Results via PLC, LAN and SMS
  • Verified by US-EPA ETV


The main components of the Colifast ALARM are the incubator reaction chamber, a flow injection pump system for liquid handling and a detector system including wavelength specific emitters combined with a spectrometer. The detection of down to 1 viable target bacterium is based on bacterial growth, group specific enzyme activity and measured concentrations of a fluorescent product (ppb MU). An increase in the number of target bacteria means an increase in the amount of β-D-glucuronidase (E. coli specific enzyme). The enzyme hydrolyses the growth medium substrate that releases MU (the fluorescent product) which yields a higher fluorescence signal on the Colifast ALARM. The Colifast growth media contains inhibitors to prevent growth of non-coliforms. The Colifast ALARM is verified by EPA's ETV program.

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