Aim:
The aim of the work was to assess the quality of water from the public waterworks of the Piaseczno district in the years 2012-2016. The data were collected within the framework of health surveillance in accordance with the 2015 regulation on the quality of water intended for human consumption.

Material and Methods:
As part of the sanitary supervision pursuant to the 2015 regulation on the quality of water intended for human consumption, the analysis was based on the results of water samples taken from public waterworks in the years 2012-2016. The registry of communicable diseases and the annual reports on occurrences of infectious diseases, infections, and cases of poisoning available in the District Sanitary-Epidemiological Station in Piaseczno were also used.

Results:
Both microbiological and physicochemical parameters were evaluated. Based on the analysis, it was found that in microbiological terms, coliform bacteria accounted for the largest number of unsatisfactory results, while the largest number of unsatisfactory results in physicochemical terms were due to exceeded levels for: turbidity, iron, and manganese.

Conclusions:
The quality of water supplied in the supervised area was satisfactory. Constant supervision by the State Sanitary Inspection and active monitoring of the quality of water supplied by plumbing and waterworks companies in the Piaseczno district resulted in the absence of water-dependent diseases.