Yifan Wang and Wenxin Qu of Wuhan Water Group Company Limited present the utility’s ‘Safe Mode’ for water treatment plant operation during the COVID-19 pandemic.
Wuhan Water Group Company Limited is the largest water supplier in the Wuhan metropolitan area, Hubei Province, China. The company operates 10 water treatment plants (WTPs) with a total capacity of 3.37 million m3/d and serves a population of 4.73 million residents.
Before the Wuhan government announced the lockdown policy for the city on 23 January 2020, Wuhan Water made a series of preparations to keep serving the city continuously and safely during the pandemic. The company held a special meeting on 22 January. All units and all employees were required to prepare for the emergency response as soon as possible.
The company set three objectives: maintaining the water supply, meeting water quality standards, and protecting employees. This was not easy work, since it suffered from insufficient supplies, lack of information about the novel coronavirus, SARS-CoV-2, and the situation was worsening day by day at that time.
The managers and engineers set three principles: (1) to rely on themselves; (2) the director of each unit should lead the way; (3) to be prepared earlier, and more adequately. The water company purchased materials for routine operation and personal protection equipment, including face masks, protective clothing, infrared temperature monitors, and mobile ultraviolet lamps for room disinfection. Employees with upset health were required to work online from home and report their temperature daily.
The ‘Safe Mode’ for water treatment plant operation
The lockdown policy of Wuhan city brought great difficulty to water company operation. Meanwhile, strict quarantine was very important for epidemic control. Wuhan Water tried its best to adapt to this situation and develop a new operation mode to maintain service, named the ‘Safe Mode’. This was applied as of 25 January 2020, right after the lockdown of Wuhan on 23 January 2020. It remained in place until the end of April 2020, approximately 20 days after the opening of Wuhan on 8 April.
The Safe Mode includes two principles. One is to apply a strict four-level hierarchical isolation to cut off the transmission route of the SARS-CoV-2 virus: the isolation of each water treatment plant (WTP) and water company office from society; the isolation of on-duty personnel from other people; the isolation of on-duty personnel from their lodgings; and the social distancing of personnel during standby at home. The second is to apply comprehensive measures covering administration, operation, commuting, occupational safety, and physiological and psychological healthcare for employees, and so on.
The core requirements
The first of four basic requirements for the Safe Mode is to minimise the contact of staff in the WTP with the outside. Each WTP was kept strictly isolated from the outside society. Only the basic logistics of reagents, daily diet and personnel protective equipment were allowed to be taken into the WTP, to reduce risk of infection. Only the basic tasks were conducted by staff in the WTP to maintain normal production. This operation mode is similar to the ‘Safe Mode’ of a personal computer’s Windows operating system.
The second is defence in depth. Several parallel working teams were assembled for each WTP or core branch of the water company. If one person in one team got infected, the whole team would be quarantined, and the alternative team could back up quickly to ensure continuous operation. When one working team is on duty, another team stands by in the WTP lodgings. The remaining teams stayed at home as the backup. A general reserve force composed of the experts or senior engineers in the head office can act as a further option.
The third is to minimise the working team for WTP operation. This involved selecting experienced workers who can handle multiple tasks to minimise the personnel needs, which would reduce the risk of personnel being infected and reduce the resource consumption and logistics workload.
The fourth requirement relates to the working period of each team. The working period and standby period of each team were set at 14 days each, according to the knowledge of the incubation period of SARS-CoV-2.
To support these requirements, Wuhan Water set up a new management framework to address the situation of the COVID-19 pandemic. The management framework comprises four groups: WTP operation management group; Logistics management group; Equipment maintenance group; and Comprehensive support group.
Measures for comprehensive safety
The three objectives for Wuhan Water were set as: ‘No violation of drinking water quality standards can be allowed for a moment’, ‘no water shortage can be allowed for a moment’, and ‘no employee can be infected on duty’. Five aspects of management measures have been conducted to achieve the goals: production safety, water quality management, epidemic prevention and control, logistics support, and human welfare.
Production safety measures included activities to ensure treatment processes, such as optimised operation of sedimentation tanks, and suspending the reuse of backwashing water. They also included strengthening instrument inspection and maintenance, and setting up the emergency repair team to be on call 24 hours per day, which included the technicians in the electrical and mechanical fields.
Water quality surveillance activities included strengthened monitoring of source water quality. For treated water, limits set included that the CT value for free chlorine disinfection should exceed 30 mg/l.min.
For pandemic prevention and control, strict disinfection was implemented, entry and exit management were strengthened, and guidance on personal protection and tracking of health status was undertaken. The company also implemented an online mode work to minimise contact between employees. The canteen provided meal boxes for employees, instead of them eating in the hall.
Activities around logistics support included all lodgings for employees being reorganised to satisfy the goal of ‘one lodging, one bathroom, one person’. Basic furniture, bedding, daily necessities, as well as washing machines were provided in each lodging, along with meals. Commuting was organised carefully after the lockdown measures for Wuhan city were implemented, when no personal traffic was permitted. Wuhan Water applied for the pass cards for commuting vehicles from the government, picked up employees from home, and drove them to the working area.
Welfare measures included the administrative team calling family members to understand their situation and demands, carrying out health screening, and caring for the contained workers on duty.
The ‘Safe Mode’ has proven to be a successful way to maintain the normal water supply under the severe situation of the COVID-19 pandemic. With the collaboration of each employee, the goals of achieving excellent water quality, sufficient water supply capacity, and zero infection of employees on duty was achieved.
Item based on a paper written in Chinese by Yifan Wang and Wenxin Qu of the Department of Drinking Water Production, Wuhan Water Group Company Limited, Wuhan, Hubei Province, China.
Paper translated into English by Jiaqi Zhang and Chao Chen of the Research Institute for Environmental Innovation (Suzhou), Suzhou, China. Dr Chen is also Associate Professor at the School of Environment, Tsinghua University, Beijing, and a member of the IWA COVID-19 Task Force.
The paper was kindly provided by the original authors for dissemination through the IWA COVID-19 Task Force. For the full paper, see https://iwa-network.org/news/information-resources-on-water-and-covid-19/