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
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
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
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
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.
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
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
By Ian Ho, Senior Process
Engineer at Harrison Grierson
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