OceanAlpha Celebrates 5 Years of Serving Water Supplies Department HK to Secure Drinking Water Safety | OceanAlpha

Since 2017, the Water Supplies Department (“WSD”) Hong Kong has introduced five autonomous water sampling and monitoring boats from OceanAlpha in batches. These unmanned surface vessels (“USVs”) regularly monitor water quality in the impounding reservoir to keep track of water quality.

OceanAlpha’s USVs Performing Water Sampling at the Plover Cove Reservoir

(Source: youth.gov.hk)

Background

 Plover Cove Reservoir (“PCR”) is Hong Kong’s impounding reservoir with the largest surface area. As the city’s primary drinking water source, the freshwater stored in PCR can meet drinking water needs for nearly one hundred days of 7 million Hong Kong people. In practice, however, the reservoir’s water quality may sometimes be affected by natural environmental conditions or unexpected incidents. For instance, a change of weather may lead to excessive growth of algae, causing an impact on water quality. 

The WSD monitors water quality and collects water samples in the impounding reservoir regularly to keep track of any changes in water quality to ensure drinking water safety to stay in line with World Health Organization’s (WHO) Guidelines for drinking-water quality (GDWQ).

USV System Workflow for Water Quality Monitoring and Sampling

(Source: wsd.gov.hk)

 Product and Application

 The WSD has introduced a new USV system equipped with OceanAlpha ESM30 autonomous water sampling and monitoring boats to enhance water quality monitoring further. Each USV is equipped with a water quality monitoring unit to monitor temperature, conductivity, turbidity, dissolved oxygen, pH, chlorophyll-a, and blue-green algae. The Global Positioning System receivers and an obstacle avoidance system equip the USVs to navigate obstacles during operation.

The four USVs can monitor different parts of the surface of PCR, which is 12 km2 in surface area, and record the distribution and changes of surface water quality at the impounding reservoir. It used to take at least a few days for traditional vessels to cover the whole area, while the workload could be accomplished within one day by the USV crew.

OceanAlpha ESM30 USV

Advantages

  1. Easy to Operate & Deploy:

USVs can be operated by a trained technician, whereas traditional vessels have to be driven by a licensed vessel operator. Also, the technician can deploy the whole USV system to work at various impounding reservoirs in water quality emergencies.

  1. Efficient:

USVs are smaller in size and can travel to relatively narrow or shallow areas in impounding reservoirs. Moreover, they can simultaneously cover several monitoring points for higher efficiency.

  1. Integrated Measurement:

The USV system can generate water quality graphical reports concerning the topographic map of the impounding reservoirs, making it easier to diagnose the distribution and trends of water quality data. 

  1. Environmentally Friendly:

OceanAlpha ESM30 USV uses new energy to avoid pollution for drinking water protection. In the case of the PCR, a solar panel system installed outside the USV storage house generates electricity for operation.

“Based on routine and USV’s monitoring data, the water quality of the PCR has been consistently steady and satisfactory.” according to the waterworks chemist of the WSD, Mr. Tang Ho-wai.

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