Continuous remote monitoring techniques for water quality

For water quality under the Act, ongoing reporting and monitoring are required and therefore the need for more technologically advanced solutions to provide more cost-effective and reliable data are essential.

APEM use continuous monitoring technology to provide instant alerts, which identify changes in water quality, this provides our clients in the water industry with the ability to be reactive to incidents and make decisions immediately.

We work with a third party technology provider to install water quality monitors. This ‘black box’ technology is about the size of a small suitcase and is usually installed both upstream and downstream of a discharge point in a river. Electronic sensors provide a signal every 15 minutes and this data can be accessed remotely by APEM experts or our clients from a smartphone or desktop.

Typical continuous monitoring systems in situ

What can be monitored?

A range of parameters can be monitored, which include:

• pH which indicates how acidic the water is
• The amount of dissolved oxygen present in the water important for supporting healthy aquatic life
• Temperature
• Conductivity to indicate the concentration of chloride, nitrate and phosphate dissolved in water
• Ammonia – a pollutant found in sewage effluent and livestock waste, can become toxic to aquatic life
• Turbidity – a measure of relative clarity of a liquid

However, the key factor that can be monitored is the relative change in water quality, if there is a sudden change this could indicate a pollution event.

The benefits of continuous monitoring are many and include:

• Instant alerts when deterioration is detected by a monitor
• Can be positioned in multiple locations in rivers (up and downstream of discharge points), as well as sites which may be difficult to access regularly
• Data is captured and stored centrally, giving clients access at any time, 24/7
• Sites can be monitored remotely, reducing the travel time spent on regular survey visits
• Trends can be identified quickly, helping to support better decision making

The evolution and use of technology does not remove the need for laboratory testing, which confirms the data and adds additional data for parameters that cannot be measured remotely. APEM provides an end to end solution, from setting up continuous monitoring programmes, providing regular reports and recommendations, through to in field sampling and both freshwater and marine laboratory testing, all under one roof.

Example data output

APEM’s water quality team recently installed a set of continuous water quality monitors and rain gauges for a water company. This will allow them to assess and respond to the potential impacts from assets during wet weather events on local bathing water quality.

A control panel and rain gauge installed to support a bathing water quality investigation

In our installation video you can see water in the river flowing out through two sluices. If the water level exceeds a certain height, two large pipes (which you can see in the video) start up and pump the extra water away. All the water in the river goes into the sea at a nearby bathing water.