On 24 September 2026, Středočeské vodárny (Central Bohemian Waterworks) announced that water from the water reservoir Odolena Voda could not be used for drinking, because samples showed above-limit concentrations of lead [2][3]. The reservoir supplies Hoštice, Husinec, Klíčany, Klecany, Máslovice, Odolena Voda, Postřižín, Řež, Sedlec, Větrušice, Vodochody and Zdiby [2].*

Measured values

The hygiene limit for lead in drinking water is ten micrograms per litre under the regulation [3]. On Thursday, two of twelve samples from the water network exceeded the limit, containing 29.5 and 24.4 micrograms of lead per litre [1][3]. In the Řepínský důl catchment area, the waterworks found above-limit amounts of lead in 16 of 36 monitored wells and shut down 14 of them; in four wells the concentration exceeded 100 micrograms per litre [1]. The outage is being replaced by water from a neighbouring well field [1].

On Saturday 26 September, a sample from the upper reservoir in Odolena Voda contained 41.1 micrograms of lead per litre, and the waterworks shut down one chamber of the reservoir [1]. Two further Saturday samples from the same place already met the limit [1]. On Saturday, 23 of 24 samples complied with the limit; in the following analyses all published results from the area complied with the limit, the highest value being 7.1 micrograms per litre, but the water remained undrinkable [1].

Measures

The restriction applied from Thursday 24 September and affected 5,133 supply points in twelve municipalities [1]. The water can be used without restriction for personal hygiene and cleaning [2]. The waterworks arranged replacement supply by tankers, with priority for schools, kindergartens and healthcare facilities [2]; on Saturday they had 35 tankers with a volume of 88 cubic metres in place [1]. Hygiene officials stated that the limit takes into account chronic exposure to lead and that they do not expect an adverse health effect from accidentally drinking, or briefly consuming, water with a concentration of around 30 micrograms per litre or lower [1].

Cause

Because of the contamination, the waterworks filed a criminal complaint against an unknown offender and turned to the Czech Environmental Inspectorate [1]. According to them, one possible source is the nearby former landfill Kasova Rokle [1]. They do not yet know the cause of the Saturday value in the upper reservoir; a spokeswoman for the waterworks said it could have been related to sediment in the tank [1]. Checks were to continue on Monday [1].

Restoration of drinkability

On 2 October 2026, the crisis staff of Středočeské vodárny declared the water in the areas supplied from the Odolena Voda reservoir drinkable again [4][6]. The decision was based on a series of compliant sample results taken at several points of the distribution network in the preceding days [5]. In terms of lead content, the water meets the set hygiene limits and is suitable for drinking and preparing food [6]. The number of consecutive compliant samples needed to restore drinkability was not set in advance; according to Central Bohemian hygiene officials, the decision rests with the water supply operator [5]. The waterworks said that detailed monitoring of water quality will continue, including at weekends, and that where even a low concentration of lead is found, the water network will continue to be flushed [5]. Where part of the house plumbing has not been used for a longer time, they recommend letting the water run for five to ten minutes before using it for drinking and cooking [6]. The restriction applied to twelve municipalities with roughly fifteen thousand inhabitants [5]. Police are examining the case on suspicion of negligent damage to and endangerment of the environment [5].

Related articles: Odolena Voda

Chronology

  • — Středočeské vodárny declared the water from the Odolena Voda reservoir drinkable again; the restriction over above-limit lead content, which affected twelve municipalities, had been in force since 24 September. iROZHLAS Pražský deník
  • — Water from the Odolena Voda reservoir was declared unfit to drink because of excessive lead; around 20,000 people were left without drinking water. ČTK / České noviny ČT24

Sources

  1. ČTK / České noviny — 26 September 2026
  2. ČT24 — 24 September 2026
  3. Seznam Zprávy — 24 September 2026
  4. iROZHLAS
  5. Pražský deník
  6. Ekolist.cz