Another Mazovia Municipality Faces Severe Water Contamination Crisis

On July 23, 2026, sanitary inspectors banned the use of tap water for drinking and hygiene in parts of the Sońsk and Nowe Miasto municipalities due to enterococci bacteria.

Gościmin Wielki Water Supply Contaminated with Enterococci

The Sońsk Commune Office is facing another serious problem regarding the quality of water supplied to residents. In samples taken from the Gościmin Wielki water supply system, intestinal enterococci were detected, which is why the sanitary inspection deemed the water unfit not only for drinking, but also for sanitary and hygienic purposes. It can be used exclusively for flushing toilets. The restrictions cover part of the Sońsk commune and the Nowe Miasto commune.

The announcement by the State Poviat Sanitary Inspector in Płońsk was issued on July 23, 2026. It was based on the results of samples taken two days earlier, on July 21. Intestinal enterococci were found both in the water treated at the Water Treatment Station in Gościmin Wielki and in a sample taken from a private apartment in that locality. At the station’s outlet, one colony-forming unit of bacteria per 100 milliliters of water was detected, while in the residential building, two units per 100 milliliters were found.

Strict Prohibition on Consumption and Hygiene Use

The introduced ban means that tap water cannot be used for drinking, preparing meals and beverages, washing fruits and vegetables, rinsing dishes, brushing teeth, bathing, or other hygiene-related activities. The announcement does not provide for the possibility of using the water after boiling it. This is therefore a much stricter restriction than in cases where the sanitary inspection permits water consumption after a two-minute boil.

The Gościmin Wielki water supply system serves approximately 6,600 residents. It covers part of the town of Nowe Miasto and 33 localities situated in the Nowe Miasto and Sońsk communes. On the Sońsk commune side, the problem concerns, among others, Gąsocin, Soboklęszcz, Komory Dąbrowne, Gutkowo, Bądkowo, Łopacin, Spądoszyn, Kosmy Pruski, Cichawy, and Gucin.

Alternative Water Supply and Ongoing Disinfection

For the Sońsk Commune Office, this means the necessity of organizing an alternative water supply for residents. The commune informed that from July 24 until further notice, water is being distributed in Gąsocin at the square near the communal library. The point is to serve residents of localities supplied by the Water Treatment Station in Gościmin Wielki.

At the same time, repair actions and disinfection are being carried out within the station and the water supply network. The applied measures may cause a noticeable change in the smell and taste of the water, but this does not mean its suitability has been restored. The ban will remain in force until subsequent tests are performed and a new announcement is issued by the sanitary inspector.

Repeated Water Quality Issues in 2026

This is not the first problem with the quality of water from the Gościmin Wielki water supply in 2026. In January, an increased manganese content was found. The water was then deemed conditionally fit for consumption, as the exceedance could primarily affect its taste, smell, and cause brown sediment and discoloration. In mid-February, tests already showed compliance with physicochemical requirements.

Further irregularities appeared in April. Coliform bacteria were detected in the samples at that time. Residents could use the water for consumption purposes only after a two-minute boil. Disinfection brought improvement, and on April 24, the sanitary inspection reported that the water quality once again met microbiological requirements. However, the July detection of intestinal enterococci led to the introduction of a complete ban on using the water for consumption and hygiene purposes.

Simultaneous Restrictions at the Gołotczyzna Water Supply

The situation is particularly difficult for the local government because problems also affect the second water supply system in the Sońsk commune. In the water from the Gołotczyzna water supply, which serves about 1,800 residents of Sońsk, Gołotczyzna, Strusinek, Strusin, Dziarno, Burkat, and parts of the locality of Szwejki, single coliform bacteria were found. According to the latest announcement from July 14, water from this intake can be used for drinking and preparing meals only after boiling. However, neither Escherichia coli nor fecal enterococci bacteria were detected there.

The Sońsk Commune Office must therefore simultaneously provide information and assistance to residents using two water supply systems subject to restrictions. In the case of Gołotczyzna, the obligation concerns boiling water before consumption, whereas in localities supplied from Gościmin Wielki, tap water must not be used even after boiling. Restoring normal supply will only be possible after the completion of disinfection and obtaining correct results from subsequent tests.