ABSTRACT
Objective To understand the water quality of self-supply wells in four provinces of northern China (Heilongjiang, Beijing, Inner Mongolia and Tibet), so as to provide a reference for supervision and management of self-supply wells. Methods Water were sampled from 233 self-supply wells in four northern provinces of China according to standard examination methods for drinking water (GB/T 5750-2006). In total, The samples were tested for 27 kinds of water quality parameters involving sensory properties, chemistry, bacteriology and toxicology, and then evaluated. Results The total unqualified rate of water quality in self-supply well water in four northern provinces of China was 52.36%. The water quality varied greatly among provinces. As for Heilongjiang, the main unqualified indicators of self-supply wells water involved turbidity, visible to the naked eye, manganese, arsenic and nitrate. In relation to Beijing, these referred to the nitrate and microorganism. In case of Inner Mongolia province, these included sulfate and fluoride. With reference to Tibet, these were zinc and chloride. Conclusions To ensure the safety of drinking water for residents, the management, disinfection and purifying measures of self-supply wells should be strengthened basing on their regional differences and water quality characteristics.