Ⅰ. Necessity and Purpose of Research
o Deterioration of wastewater treatment facilities
ㅇ In 2020, there were 221 public wastewater treatment facilities nationwide (nine national industrial, 124 local industrial, and 88 agricultural facilities), 36 of which were constructed 30 years ago.
ㅇ 76 facilities (34% of all facilities) are expected to exceed their useful lives by 2030.
ㅇ However, the deterioration problem has not been reported so far.

o Problems in the operation of wastewater treatment facilities
ㅇ Problems in the operation of wastewater treatment facilities, such as the low utilization rate, deviation in the design water quality and operated water quality, constant violation of the water quality standards, and continuous financial support of the local governments for operation costs, have occurred chronically.

o Policy requirement at the central government level
ㅇ Until now, the management of wastewater treatment facilities at the central government level has focused on water quality management.
ㅇMeasures to improve the operation method through institutional improvement have not yet been prepared.
ㅇ Operational and management problems of public wastewater treatment facilities need to be analyzed first, and the central government have to prepare preemptive countermeasures in the improvement of the operation-related problems and suggest future directions for reinvestment.

Ⅱ. Status of Public Wastewater Treatment Facilities
1. General status and deterioration conditions
o General status of wastewater treatment facilities
ㅇ In 2020, there were 221 public wastewater