What Is Drinking Water?
Drinking water analysis examines water intended for human consumption against the parameters defined in legislation. Parameters fall into three groups: microbiological (E. coli, enterococci), chemical (heavy metals, nitrate, pesticides, disinfection by-products) and indicator parameters (conductivity, pH, turbidity, iron, manganese).
Purpose of Drinking Water
The purpose is to show the water is safe for human health and meets the parametric values in legislation. Regular monitoring is mandatory for mains water, well water and bottled water.
Which Products Is Drinking Water Applied To?
- Mains drinking water
- Well and spring waters
- Bottled drinking water
- Process water used in food production
- Storage tank and plumbing waters
In Which Sectors Is Drinking Water Used?
Standards Related to Drinking Water
- TS EN ISO 5667-5 (sampling of drinking water)
- TS EN ISO 9308-1 (E. coli and coliform bacteria)
- TS EN ISO 7899-2 (intestinal enterococci)
- TS EN ISO 17294-2 (determination of elements by ICP-MS)
- TS EN ISO 10304-1 (anions by ion chromatography)
- TS 266 (waters — water intended for human consumption)
Drinking Water Conditions
- Sampling
- Tap disinfection and flushing time are defined in the standard
- Disinfectant neutralisation
- A sterile container with thiosulphate is used for the microbiological specimen in chlorinated waters
- Time
- Microbiological specimens must be analysed within the short time defined in the standard
- Monitoring type
- Routine and audit monitoring have different parameter lists
Equipment for Drinking Water
- Membrane filtration system and incubators
- ICP-MS
- Ion chromatography
- GC-MS (disinfection by-products, pesticides)
- Turbidimeter, pH meter and conductivity meter
Sample Requirements for Drinking Water
- Sampling is the largest component of total uncertainty in environmental analysis. The specimen container, preservation (acidification, cooling, storage in the dark), fill method and time to reach the laboratory are all defined in the standard; if any one is not met, the result loses its validity. Sampling must be carried out by authorised personnel per a written plan.
- The microbiological specimen must be taken in a sterile container with thiosulphate
- Separate containers and preservation are required for chemical parameters
- Sampling point and free chlorine value must be recorded on site
Duration of Drinking Water
Microbiological parameters take as long as the incubation period. Chemical parameters take several working days; pesticide and disinfection-by-product screens take longer.
Drinking Water Procedure
- 1Monitoring type and parameter list are determined.
- 2The tap is prepared and a specimen is taken per the standard.
- 3pH, temperature and free chlorine are measured on site.
- 4Specimens are delivered to the laboratory via cold chain.
- 5The relevant standard method is applied for each parameter.
- 6Results are compared against the parametric values.
Drinking Water Acceptance Criteria
(EU) 2020/2184 defines parametric values for microbiological, chemical and indicator parameters; the requirement of absence per 100 mL applies for E. coli and enterococci. National legislation's values and monitoring frequencies also apply.
Evaluation of Results
Exceeding indicator parameters does not directly mean a health risk but requires investigating the cause; exceeding microbiological and health-related chemical parameters requires immediate action. The sampling point determines the result: water compliant at the network entry can become non-compliant at the tap due to plumbing-related contamination.
Drinking Water Report
- Sampling point, date and field measurements
- Monitoring type and parameter list
- Method, result and limit of quantification for each parameter
- Measurement uncertainties
- Parametric values compared against
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- (EU) 2020/2184 Drinking Water Directive
- 98/83/EC (previous, now repealed directive)
- 2000/60/EC Water Framework Directive
Environmental Analysis — What Does This Testing Field Cover?
The section below describes the field that the Drinking Water test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Environmental analysis determines the presence and concentration of pollutants in water, soil, waste, air and flue gas samples. The output of this family is usually part of a permit, a declaration or an inspection file; the result has direct legal consequences.
In this family SAMPLING is half the result, and this is the feature that most sets the field apart. A sample taken at the wrong time, in the wrong container, under the wrong preservation or from the wrong point gives an invalid result no matter how well it is analysed in the laboratory. In waste water a grab sample and a composite sample give different information; in soil, surface and depth produce different results. Sampling therefore has its own standards and its own accreditation scope.
On the water side, physico-chemical parameters (pH, conductivity, turbidity, COD, BOD, suspended solids), ions, heavy metals, organic pollutants and microbiological parameters are measured. Drinking water and waste water carry different parameter sets and different limits; the same laboratory method leads to a different decision under the two regimes.
In soil and waste, heavy metals, hydrocarbons, PAH and PCB compounds and LEACHING BEHAVIOUR are determined. The leaching test carries a logic peculiar to this field: it is not the total amount of a pollutant in soil but the fraction that can pass into water that determines the environmental risk. Waste classification and the disposal decision rest largely on this test.
On the emissions side, dust, sulphur dioxide, nitrogen oxides, carbon monoxide, oxygen, moisture and total organic carbon are monitored in flue gas. Measurement is made on site under operating conditions and must represent the plant's actual operating regime; a measurement taken at low load does not show the emissions at full capacity.
Continuous measurement systems are a separate body of work. In large plants emissions are monitored continuously and the accuracy of these systems is verified periodically by comparison with independent measurements; the quality assurance framework governs this.
Noise and vibration measurements complete the environmental impact side of the field: environmental noise mapping, workplace noise exposure and vibration exposure measurements produce evidence for both environmental and occupational health legislation.
Method groups in this field
Sampling
Separate sampling standards for water, waste water, soil, waste, flue gas and ambient air; grab, composite and continuous sampling techniques.
Water physico-chemical
pH, conductivity, turbidity, colour, suspended solids, COD, BOD, TOC, alkalinity, nitrogen and phosphorus species.
Elemental analysis
Determination of heavy metals and trace elements in water, soil and waste by ICP-OES and ICP-MS.
Organic pollutants
Volatile organic compounds, PAH, PCB and organochlorine pesticides by GC-MS; hydrocarbon oil index.
Flue gas
Measurement of dust, SO2, NOx, CO, O2, moisture and total gaseous organic carbon; quality assurance of automated measuring systems.
Leaching and waste characterisation
Leaching tests and waste classification parameters; the basis for the disposal decision.
Commonly confused in this field
- An analytical result cannot be used on its own without the sampling record; the time, point, conditions and chain of custody are part of the report.
- Total content and leachable amount give different information; in waste classification, leaching behaviour is what counts.
- Emission measurement must be made under representative operating conditions of the plant; a result taken at partial load is misleading.
- Drinking water and waste water limits are defined in different legislation; the same parameter carries a different threshold under the two regimes.
- A sample from a single point does not represent the whole area; assessment of a contaminated site requires a grid-based sampling plan.
Which decisions these results support
- Compliance with environmental permits and discharge limits
- Quality assurance of continuous emission measurement systems
- Contaminated site assessment and the remediation decision
- Waste classification and selection of the disposal method
- Workplace exposure measurements and occupational health obligations
Related Tests
Frequently Asked Questions About Drinking Water
Which parameters are needed for our well water?
It varies by intended use. If for human consumption, the legislation's routine monitoring list is the minimum requirement; parameters must also be added per local geological risks (arsenic, fluoride, nitrate) and surrounding activities.
Should the specimen be taken from the tap or the tank?
Legislation is based on the point reaching the consumer. To find the source of a problem, however, the tank, network entry and tap points must be sampled together; a single point does not show the source.