Why bother with Smart Monitoring?

There is an explosion of data and information for testing the quality of our drinking water. For instance, one sand filter will generate in excess of 1.5 million datapoint to satisfy the DWSNZ requirements.

Yet, it’s impossible to effectively use all this data and information.

Good monitoring regimes should reflect the specific characteristics and seasonality of the site concerned. A regime, which is too rigid, may provide too little or too much information.  A too flexible regime may be impractical or too costly. Finding the right balance is the key.

Below are examples of how an appropriate sampling regime can be effective.

Case 1 - Coloured and Odourous Water Complaints

A council approached us for a second opinion because its customers were complaining about seasonal significant decolourisation and odour at their water taps.  The council had been advised that the powdered activated carbon dosing was the likely culprit.

When we requested more information, it became clear that the council’s previous advice was based on hypothesis instead of facts. No additional monitoring data was collected to back up the advice. It was disappointing but unfortunately all too common to hear that unproven advice was given.

The reality is that the cost of the additional analysis was insignificant compared to the cost of damaged reputation of the council and the cost of the temporary rectification measures.

The council has since applied a more flexible and proactive monitoring programme with action plans, which has led to a steady improvement in water quality.

Case 2 – Illegal Discharges

A client expressed concern about elevated nitrogen level in the final effluent after a new biological process was commissioned. Fingers were quickly pointed at the design team and the contractor for under-sizing the biological process.

However, because adequate monitoring data was collected during the same period, we could prove this assumption was incorrect. The results showed that the incoming sewage characteristics were very different to those typically seen in municipal wastewater, and were between 5 and 10 times more than expected.

In fact, the plant (the biological process) had survived five days consecutive dumping of illegal discharges. The data set not only proved where the responsibility lay but also saved a lot of headaches for the contractor, the designers and the asset owner/operator.

Case 3 – NEWater in Singapore

Recycling of treated wastewater is one of the four water sources in Singapore. Most of the treated wastewater (NEWater) is currently used by the high-tech industries due to its superior quality.

The Singaporean Government has made significant investment in online monitoring and laboratory analysis of the NEWwater. The goal is to provide a comprehensive water quality database for internal uses and to build an extensive record to demonstrate to the public that the NEWater is a consistently safe and reliable water source.

Their plan is to use the long term monitoring data as robust evidence to their citizens when they have to switch from mainly imported water to mainly NEWater. When their water supply contract with Malaysia lapses in 2061, they will have a whopping 50 years of data and track record to convince the public. 

Final Thought

It is very common for a monitoring regime and sample collection programme not been reviewed for years. Additionally the monitoring regimes often have little consideration regarding the seasonal loads and impacts. Online monitoring is still often being seen as “nice to have”, expensive and not reliable.

As the cost of monitoring and analysis becomes less expensive, we now have the more capability than ever before to streamline the online and laboratory monitoring regimes to make them more effective. 

I once heard a water professional summing the importance of water quality, “Water is like any food product, except there is no product recall.”  Similarly, once the treated effluent from the wastewater treatment facilities is released to the receiving environment, it cannot be reversed. Therefore, we, as the water professionals, must get our treatment process right, and an appropriately designed monitoring regimes is the key.

For this very reason, it is time for the water professionals to put on their thinking caps when designing and/or customising the monitoring programmes.

By Ian Ho, Senior Process Engineer at Harrison Grierson