General information:
The total number of mesophilic germs, NTG (which develops? at 37 0C and 220C respectively) is a global indicator that allows the assessment of the water load with flora of various origins that are responsible for transmitting infections by water.
Referential after which the analysis is performed:
NTG determination analysis (total number of germs is performed at 2 themesperaturi at 37 0C and respectively 220C) for drinking water is performed within its own laboratoryato according to the standard national SR EN ISO 6222/2004.
Principle of the method:
Determination of NTG to drinking water is performed using the membrane filtration system using as a nutrient agar culture medium in aerobic medium.
Sample rejection cases – quantity of inappropriate sample, sample collected in inappropriate containers, samples not properly labelled, etc.
Columient – sterile container required. (purchased commercially - human pharmacies or requested from the laboratory).
The amount of sample required to perform the analysis - minimum 200ml.
Processing required after harvesting – not required.
Stable sample – freshly harvested water is stable for 3 hours at a temperature of 2...50C.
The analysis method - insamanatarii on nutrient agar culture medium.
Reference values according to the Law of Drinking Water 1)
| Parameter / Unit of measurement | CMA value (Maximum permissible concentration) |
|
| at 370C : no abnormal changes |
| at 220C : no abnormal changes |
Recommendations for performing the analysis/ Effects of exceeding the reference values –
The total number of germs represents the totality of microbial colonies grown on a solid agar medium. The presence of mesophilic flora in the water allows the assessment of sanitary conditions and drinking water.
In order to reduce the level of bacteria in the water, a number of methods of water chlorination can be applied depending on the severity of the infestation or UV lamps can be used.
Bibliography:
- H.G. 188/ 20.03.2002 for the approval of some norms regarding the conditions for discharging wastewater into the aquatic environment, modified and supplemented by H.G. 352/11.05.2005
