Drinking water analysis is the systematic testing of water intended for human consumption to ensure it meets safety, quality, and regulatory standards. It encompasses microbiological, chemical, physical, and radiological testing across a wide range of parameters. In the European Union, drinking water quality is governed by Directive (EU) 2020/2184 of the European Parliament and of the Council of 16 December 2020 on the quality of water intended for human consumption (recast of the former Directive 98/83/EC).
Drinking water must be:
- Free from pathogenic microorganisms and parasites at concentrations that constitute a risk to human health.
- Free from chemical substances in concentrations that pose a risk (heavy metals, pesticides, nitrates, PFAS, disinfection by-products).
- Compliant with parametric values specified in Annex I of Directive (EU) 2020/2184.
- Ovalab’s accredited water quality testing service covers all major parameter groups required for drinking water compliance.
Key Parameters and Testing Methods
Comprehensive drinking water analysis covers multiple parameter groups:
- Microbiological parameters (Directive (EU) 2020/2184, Annex I, Part A):
— Escherichia coli: Absence in 100 mL (ISO 9308-1 membrane filtration method)
— Intestinal enterococci: Absence in 100 mL (ISO 7899-2)
— Clostridium perfringens (including spores): Absence in 100 mL - Chemical parameters — heavy metals: Lead (≤10 µg/L), arsenic (≤10 µg/L), chromium (≤25 µg/L — new Directive 2020/2184 value, transitional period applies), nickel (≤20 µg/L). Analysis by ICP-MS for ultra-trace accuracy. See also: heavy metals analysis.
- Chemical parameters — anions/nutrients: Nitrates (≤50 mg/L as NO₃⁻), nitrites (≤0.5 mg/L as NO₂⁻), fluoride (≤1.5 mg/L), chloride (≤250 mg/L), sulfate (≤250 mg/L). Determined by ion chromatography or spectrophotometry.
- Physical parameters: pH (6.5–9.5), turbidity (≤1 NTU for surface water after treatment), conductivity (≤2,500 µS/cm at 20 °C), colour, odour, taste.
- Emerging contaminants (Directive (EU) 2020/2184 new additions): PFAS (sum of 20 PFAS ≤0.10 µg/L, total PFAS ≤0.50 µg/L), bisphenol A (≤2.5 µg/L), chlorate, chlorite, haloacetic acids.
Regulatory Framework
The EU drinking water framework is built on the following key legislation:
- Directive (EU) 2020/2184 (16 December 2020): The current EU Drinking Water Directive, recasting Directive 98/83/EC. Key innovations include: risk-based approach to water safety (Water Safety Plans), new parametric values for lead, chromium, and PFAS, provisions on materials in contact with drinking water, and expanded access-to-water provisions (Article 16).
- Czech Republic implementation: Directive 2020/2184 is transposed into Czech national law through Decree No. 252/2004 Coll. (as amended) on hygienic requirements for drinking water, which sets parametric values for Czech public water supplies.
- WHO Guidelines for Drinking-water Quality (4th edition): The global reference framework that underpins EU and national standards, providing health-based guideline values for a broad range of microbiological and chemical parameters.
- WHO Water Safety Plan (WSP) approach: A risk management framework covering the entire water supply chain from catchment to consumer, now embedded in Directive (EU) 2020/2184.
Laboratories performing official drinking water testing must hold appropriate accreditation. Ovalab’s ISO/IEC 17025-accredited water quality testing service provides legally valid results for compliance reporting.
Frequently Asked Questions
What parameters are tested in drinking water?
Directive (EU) 2020/2184 requires that drinking water be ‘wholesome and clean’ — free from pathogenic microorganisms and chemical substances at harmful concentrations. It sets binding parametric values (Annex I) for microbiological parameters (including E. coli and intestinal enterococci), chemical parameters (including lead, arsenic, nitrates, PFAS), and indicator parameters (pH, conductivity, colour). New requirements include a risk-based approach using Water Safety Plans, stricter limits for lead (10 µg/L), new PFAS limits, and extended provisions on materials in contact with drinking water.
Which EU directive regulates drinking water quality?
ICP-MS (Inductively Coupled Plasma Mass Spectrometry) is the preferred method for heavy metals in drinking water because it provides ultra-low detection limits (often in the sub-µg/L or ng/L range), multi-element capability in a single analysis, and excellent sensitivity for lead, arsenic, cadmium, chromium, nickel, and mercury at the parametric values set by Directive (EU) 2020/2184. For example, the lead limit of 10 µg/L requires reliable measurement well below this value, which ICP-MS achieves with high accuracy and repeatability.
How often must drinking water be tested?
Testing frequency depends on the water supply type and volume distributed. Directive (EU) 2020/2184 and implementing regulations set minimum monitoring frequencies based on supply zone population and daily volume. For large public water supplies, microbiological testing (E. coli, enterococci) is required frequently (daily to weekly), while chemical parameters are tested less frequently (quarterly to annually). Private well owners, food producers using own water sources, and building owners with internal distribution systems have specific testing obligations under national transposition legislation.
What are the EU limits for heavy metals in drinking water?
PFAS (per- and polyfluoroalkyl substances) are a group of man-made chemicals used in non-stick coatings, firefighting foams, and many industrial processes. They are highly persistent in the environment (often called ‘forever chemicals’) and have been linked to health effects including immunotoxicity, endocrine disruption, and increased cancer risk. Directive (EU) 2020/2184 introduced new parametric values for PFAS in drinking water: a sum of 20 specific PFAS ≤0.10 µg/L and total PFAS ≤0.50 µg/L. PFAS are typically analysed by LC-MS/MS due to their complex chemistry and the ultra-low limits required.
Can private wells be tested?
In the Czech Republic, drinking water testing obligations apply to: public water supply operators (waterworks companies — vodovodní společnosti), food and beverage producers using water as an ingredient, operators of healthcare facilities, restaurants, hotels, and schools with internal distribution systems, and private well owners (although private wells are not covered by the public monitoring programme). Czech Decree No. 252/2004 Coll. specifies the required tests and frequencies for different supply types. Ovalab’s ISO/IEC 17025-accredited water quality testing provides legally valid results for all compliance purposes.