Objective To investigate the detection capability for 106 water quality indicators required in the Standards for Drinking Water Quality (GB 5749-2006) as well as the main reasons for insufficient detection capability for various indicators in the Center for Disease Control and Prevention (CDC) at the provincial, municipal, and county levels of China in 2022.

Methods Data of water quality detection capability were collected from CDCs at all levels of China in 2022, and analyses were performed to investigate the proportion of institutions among provincial and municipal CDCs which lacked the detection capability for 42 regular indices and 64 non-regular indices and the proportion of institutions among county-level CDCs which lacked the detection capability for 42 regular indices, as well as the reasons for the lack of detection capability.

Results As for the provincial CDCs, insufficient detection capability was mainly reflected in total α radioactivity and total β radioactivity (4 provincial CDCs, accounting for 14%), as well as Giardia and Cryptosporidium (6 provincial CDCs, accounting for 21%), which was mainly caused by inadequate equipment configuration (100%), followed by a lack of testing personnel (50%-75%). As for the municipal CDCs, insufficient detection capability was mainly reflected in total α radioactivity and total β radioactivity (accounting for 47%), followed by the indicators for disinfectants and disinfection by-products including ozone, total chlorine, chlorine dioxide, formaldehyde, bromate, chlorite, and chlorate (accounting for 6%-22%), and the reasons for the lack of detection capability included a lack of equipment, standard products, reagents, and personnel. In terms of the non-regular indices, except ammonia nitrogen (1%), the institutions which lacked the detection capability for 63 indices, accounted for ≥ 19%, among which the institutions lacking the detection capability for Giardia and Cryptosporidium accounted for the highest proportion of 65%, with the main reasons of a lack of equipment (88%), followed by a lack of testing personnel (42%-43%), reagents (40%), and standard products (38%). While the main reasons for the lack of the detection capability for the remaining 61 indices were a lack of equipment (60%-76%), standard products (45%-62%), reagents (42%-53%), and testing personnel (51%-67%). In terms of regular indices, the CDCs at the county level had the weakest detection capability for radioactive indicators (total α radioactivity and total β radioactivity, accounting for 85%, respectively), followed by the indicators for disinfectants and disinfection by-products (ozone, total chlorine, chlorine dioxide, formaldehyde, bromate, chlorate, chlorite, carbon tetrachloride, and chloroform), and the main reasons for the lack of detection capability were a lack of equipment (83%-94%) and testing personnel (53%-76%).

Conclusion Insufficient detection capability for regular indices in CDCs at the provincial, municipal, and county levels is mainly reflected in radioactive indicators (CDCs at the provincial, municipal, and county levels), disinfectant indicators (ozone, total chlorine, chlorine dioxide), and disinfection by-product indicators (formaldehyde, bromate, chlorite, chlorate; CDC at the municipal and county levels), as well as carbon tetrachloride and trichloromethane (CDCs at the county level); as for the non-regular indices, there is good detection capability for ammonia nitrogen in provincial and municipal CDCs, and insufficient detection capability is mainly reflected in Giardia and Cryptosporidium (provincial and municipal CDCs), as well as other indicators (municipal CDCs). Inadequate equipment configuration is the main reason for insufficient detection capability, and additional equipment should be applied in the future to enhance water quality detection capabilities.