Introduction to HueWACO

Thua Thien-Hue Province (hereafter “Hue Province”) is located in central Vietnam. Its capital, Hue City, is famous as the capital of the Nguyen Dynasty, the country’s last royal dynasty. The Complex of Hue Monuments, which is evocative of the Nguyen Dynasty era, is designated as a UNESCO World Heritage Site (cultural heritage site), and the number of tourists from overseas is increasing year after year.

In 2007, HueWACO implemented its Water Safety Plan with the support of the World Health Organization (WHO), and now provides safe water across Hue Province. HueWACO was highly evaluated and selected by WHO as a model company for presenting and sharing its experiences in the country and the region. Since then HueWACO has constantly upgraded and improved the water supply system in order to maintain a sustainable, safe water supply.

“HueWACO declared Hue City’s tap water to be safe in June 2008, and did so for all of Hue Province in August 2009. During the period of 2009 till now, even though we have encountered some issues affecting safe water supply, we have come up with timely solutions to ensure its sustainability,” says HueWACO President and Director Truong Cong Nam.

In 2013, the Vietnam-Yokohama Safety Water Supply Management Project was initiated under the Japan International Cooperation Agency (JICA) Partnership Program with the aim of sharing new technologies of private companies located in Yokohama, Japan, with HueWACO and other water supply companies in Vietnam.

Constructing a System to Automatically Dose the Proper Amount of Chemicals at the Proper Time

The Vietnam-Yokohama Safety Water Supply Management Project has been providing support in four technical areas: chemical dosing control using a supervisory control and data acquisition (SCADA) system, flexible pipe method, water leakage monitoring detection utilizing L-sign devices, and rehabilitation of filtering sand. With regard to these four areas, Azbil Corporation’s role was to provide technical assistance for the use of the monitoring and control system for water purification plants. Specifically, Azbil provided support for the installation of the above system to automate the chemical dosing process at HueWACO’s Quang Te 2 water treatment plant (WTP) in order to dose the needed amount of chemicals to control the quality of water supplied. In addition, Azbil provides HueWACO with technical support for the operation of this system.

At the water treatment plant, chemicals such as PAC, polymers, KMnO4, and chlorine are dosed at various stages of the water treatment process.

Luu Ngoc Tuan, Vice Manager of Planning in the Technical Department of HueWACO explains, “The SCADA system at Quang Te 2 WTP, which was installed in 2009, just performed semiautomatic chemical dosing and the determination of chemical dosing amount was still done manually. As a result, sometimes the amount of chemicals injected did not meet the requirements, which in turn increased our production costs or affected the water quality.”

In the project, Azbil’s Harmonas-DEOTM monitoring and control system was used as the central equipment of the new automatic chemical dosing control system. The system receives data from the existing monitoring system through a gateway, calculates the amounts of chemicals to add, and controls the chemical dosing process so that the appropriate amounts of chemicals are automatically added at the appropriate times.

To prepare for the construction of the system, three HueWACO engineers were dispatched to Japan and received system-related training at Azbil’s Fujisawa Technology Center. After learning the basic technology of the automation and control system, the three engineers and Azbil Corporation began developing the control program to be installed in Vietnam.

In the central monitoring room, Harmonas-DEO monitors the flow rate of water entering the water receiving well and the degree of water turbidity, and controls the rotation speed of chemical dosing pumps and the opening and closing of control valves.

Harmonas-DEO calculates the amounts of chemicals to add and sends instructions to the chemical dosing pumps and control valves.

Advanced Methods Attract Considerable Attention from Water Utility Personnel Throughout Vietnam

The system began operation in June 2015. Detailed evaluation of data accumulated by Harmonas-DEO and full-fledged implementation of measures for correcting any glitches discovered through evaluation have not yet started, but the system has already achieved results.

“During two years of implementing the project, including all four areas, the automatic chemical dosing control at Quang Te 2 WTP has achieved definite results which the technical team of HueWACO has assessed using the advanced technologies of Azbil as well as the experience of the experts of Yokohama Waterworks Bureau (YWWB) in Japan. The automatic chemical dosing control system has helped to determine the appropriate amounts of chemicals and also has dramatically reduced the time and effort required to add in the chemicals, which contributed to better control of water quality at the plant,” says Mr. Tuan.

Chau Ngoc Long, Manager of Planning in the Technical Department of HueWACO comments, “In this project, regarding the SCADA system at Quang Te 2 WTP, owing to the support from the JICA project, Azbil Corporation, and YWWB, HueWACO was able to successfully connected the automatic chemical dosing control system to the SCADA system. HueWACO has also invested much additional machinery and equipment to ensure optimal system operation. I think this is the first success area of this project.”

A seminar on the Vietnam-Yokohama Safety Water Supply Management Project was held in June 2015 at the head office of HueWACO. In the seminar, details of efforts in the four technical areas, including the construction of the Quang Te 2 system, were presented.

“The seminar was attended by about 200 water utility personnel from 40 municipalities across Vietnam. The case study of the system built at the Quang Te 2 WTP attracted a great deal of attention from the participants and was highly evaluated,” says Mr. Long.

HueWACO plans to install a similar system at other water treatment plants operated by the company.

Mr. Nam states, “In the future, HueWACO will establish a central control center for monitoring and operation of the water supply system. In these efforts, we look forward to Azbil’s technical assistance and support for human resources development as well as machinery.”

Analyzers determine the concentration levels of chemicals, degree of water turbidity, and water quality by analyzing the water obtained through conduits, and then transmit the data to Harmonas-DEO, which implements the results of control calculations.

Training was held at Azbil’s Fujisawa Technology Center for the three engineers dispatched from HueWACO.

* Harmonas-DEO is a trademark of Azbil Corporation.