Below you will find a detailed description of water sampling procedure.

Amount of drinking water:

• For chemical analysis: 1.5 l
• For micro-biological analysis: 0.5 l

Sampling of drinking water for micro-biological analysis

Containers for samples:

• Sterile 0.5 l bottle available at the laboratory for 0.86 euro (excluding VAT);
• Other sterile containers (glass or plastic). Outside of containers must be clean.

Sampling procedure

• During the sampling, your hands must be clean or sterile gloves must be used. During the filling of sample, water cannot contact external pollution (for example, dirt from air, clothes, floor, etc.).
• External surface of tap must be clean, all the dirt that might potentially fall into the sample container must be cleaned off.
• Tap must be disinfected applying any of the following disinfection methods:
  • Tap is burnt with a hot flame;
  • Tap is soaked in a dish with 70 % alcohol solution for 2 – 3 minutes.

    Note: if sample is taken by baling from reservoir or well, inside and outside of the container must be sterile.

• After disinfection, water must be poured off to make sure disinfection does not influence the water sample, the tap cannot be hot, and no remains of disinfectant may be left on the tap.
• Initially, tap can be fully opened to let the water flow for ~10 seconds; afterwards the water flow should be halved for 2 – 3 minutes.
• If a sterile bottle is be used, it has to be prepared for sampling as follows:
• take the bottle out of the packaging, carefully unscrew it avoiding touching inside of the bottle and the lid by hands.
• Place the bottle or container used for sampling under the tap (without closing and reopening of the tap).
• Do not fill up the bottle or container ; leave some space for stirring the sample before testing.
• Bottle or container must be closed immediately, placed and stored vertically!
• If sample is taken at several places, samples have to be numbered, and sampling place shall be indicated in the laboratory application.
• Cooling down of sample down to (5 ± 3)°C temperature is recommended.
• The period between sampling and analysis must be as short as possible; submission of sample to the laboratory on the day of sampling is recommended.
• During transportation, appropriate temperature can be ensured using cooling elements or crushed ice.

Recommended storage period of a sample (including the period of transportation) – 8 hours.

Monitoring of drinking water

Indicator	Method/principle	Volume of sample	Price excluding VAT, EUR
Ammonia and the sum of ammonium ions	*LVS ISO 7150-1:1984 (spectrophotometry)	1.5 l plastic bottle	8.92
pH	*LVS EN ISO 10523:2012 (electrochemistry)	1.5 l plastic bottle	2.08
Electrical conductivity	*LVS EN 27888:1993 (electrochemistry)	1.5 l plastic bottle	2.03
Turbidity	*LVS EN ISO 7027-1:2016 (turbidimetry)	1.5 l plastic bottle	1.59
Odour and flavour	LVS EN 1622:2006 Part C (organoleptic method)	1.5 l plastic bottle	0.96
Colour	*LVS EN ISO 7887:2012 C method (spectrophotometry)	1.5 l plastic bottle	1.95
Number of coliforms and Escherichia coli	* LVS EN ISO 9308-1:2014+A1:2017	1.5 l plastic bottle	12.11
Sterile bottle			0.86

* - method is accredited

Consult with the institute “BIOR”
For detailed information, please contact our experts at the Sales Division via telephone: +371 67620359 or e-mail: sales@bior.lv.