Transcription of BACTERIAL DRINKING WATER ANALYSIS
1 BACTERIAL quality is probably the most importantconsideration in assessing DRINKING WATER . If you aresampling your WATER because you suspect a waterquality problem, you should boil your WATER beforedrinking it until test results are PEI Analytical Laboratories providesbacterial WATER testing services to municipalities thathave WATER systems, and to Island residents whosewater comes from a private well. There are fourbasic steps in testing WATER for bacteria:6collecting the sample6filtering the water6incubating the sample6reading the resultsFiltering the WaterAt the lab, a technician pours 100ml of WATER from the sample into afiltering funnel. The size of thepores in the filter is smaller thanthe bacteria being tested, so thefilter will capture the the SampleThe filter is removed fromthe funnel and placed in apetri dish containing a typeof agar which is a growthmedium for coliformbacteria.
2 It is incubated ata standard temperature,35 C, for a standard periodof time, 24 the ResultsWhen the incubation process is complete, thelab technician examines the filter - using a hand lenswith 10 times magnification - looking for bacteriacolonies with specific testing process is like a litmus test forbacteria.~E. coli appears as blue circles with eachcircle representing a colony.~Total coliform presents as pink colonies.~Background growth is usually seen as bacteria count is determined simply bycounting the number of colonies with the resultsreported in counts per 100 ml. The filters that areused have a grid which makes the task of countingthe colonies DRINKINGBACTERIAL DRINKINGBACTERIAL DRINKINGBACTERIAL DRINKINGBACTERIAL DRINKINGWAWAWAWAWATER ANALTER ANALTER ANALTER ANALTER ANALYSISYSISYSISYSISYSISC ollecting the SampleWater samples must be collected in sterilizedbottles which can be picked up at any Access PEIC entre.
3 To collect the sample, remove the strainerfrom the tap and let the WATER run for five minutes toensure a fresh sample is coming from the well itselfand not the pipes orpressure tank. Reducethe WATER flow whenfilling the bottle so thewater does not not allow the bottleto overflow, and becareful not to touch therim of the bottle or theinside of the cap to anyother the sample is taken, keep it in the refrig-erator until it is delivered. Samples taken for watertesting must be fresh , that is less than 24 hours oldand preferably much less. Delivering the samplewithin a couple of hours of sampling is 2007 What the Results MeanWhat the Results MeanWhat the Results MeanWhat the Results MeanWhat the Results MeanE. coliWhen E. coli is detected in WATER it usuallyindicates fecal contamination - either from human,agricultural or wildlife sources.
4 Any count of bacteria would make the WATER unfit to drink. Mixed CultureTotal ColiformColiforms are a group of bacteria found insoil, on vegetation and in large numbers in theintestines of warm-blooded animals includinghumans. They are not normally found ingroundwater that is well protected from are not disease-causing organisms, butthey serve as an indicator of the sanitarycondition of a WATER supply. If coliform bacteriaare present, it may be possible for E. coli or otherdisease-causing bacteria to enter the growth is an indicator of thegeneral BACTERIAL population in a sample. It is onlya concern if the count exceeds 200 per 100 ml. Inthat case, it may be an indication that the waterpipes or other aspects of the system may need tobe inspected and flushed.
