Wastewater Treatment Plants that Speak


Pollution is to be prevented in the first place but even after prevention, pollution is often not fully eliminated. Pollution needs to be adequately treated before discharge so that the environment is not adversely affected.

Take the case of managing wastewater. Industries generate wastewater from manufacturing processes, from utilities (boiler operations and cooling water discharges) and from sanitary use. One can reduce the wastewater generated by modifying the manufacturing process (e.g. using “dry” operations instead of “wet”) or by recycling wastewater back in the process, Wastewater after some treatment could also be used for washing or low grade operations  All these efforts lead to wastewater flow and load reduction. The wastewater that is left over needs to be treated as an “end of the pipe measure” so that the stipulated wastewater standards are met. These standards are listed  specific to pollutant concentrations by the regulator (such as Pollution Control Board) with a belief that if the standards are met then the receiving environment will stay protected.

It is not surprising therefore that we see a number of wastewater treatment plants built and operated by individual industries and by industry associations as common effluent treatment plants (CETPs), a treatment facility shared by industries in a cluster. These treatment plants are inspected by the officers of the Pollution Control Board (PCB) and samples of the treated wastewater are taken and tested in the laboratories to ensure that the plants are in compliance. The industries where non-compliance is found, actions are taken such as warnings (show cause notices). In cases of persistent non-compliance, closure notices are issued or fines are levied

I have a problem in believing or trusting the above “system” of monitoring & enforcement. Firstly, the wastewater treatment plants are seldom operated by trained or certified operators. In India, we don’t have a requirement of certification so – “anybody” can operate a wastewater treatment plant. I am always intrigued by the fact that while industries do spend considerable capital expenses in building wastewater treatment plants, they simply ignore the plant operations and do not get skilled people to operate, or pay them well and provide them a career progression.

Can you think of an operator getting a raise in salary because he operated the wastewater treatment plant in 24×7 compliance? How about an operator who could reduce the specific energy consumption (KJ/m3) of the wastewater  treatment plant while remaining in compliance. This operator should be felicitated and paid a bonus proportional to the energy bill saved! This does not happen.

While satisfactory operation of the wastewater treatment plant is an issue, the other problem is relatively low experience of the staff of the PCB in plant inspection and sampling. Most of the times, the staff (that is typically a field officer) is not well trained on how to walk through, inspect and assess the plant performance. The officer is sometimes not familiar with the treatment process or the equipment or does not hold a prior experience that has given him an eagle’s eye of inspection. So in most instances, the task of inspection and monitoring gets poorly performed.

The brunt of non-compliance is then received by the environment despite investments made, staff deployed and numerous monitoring reports prepared!

I spoke about my frustration to Professor Friend. He was in a hurry and was stepping out of his secret research laboratory (This lab was set up in the basement of Income Tax office in Mumbai, location not known to most people. Professor had a conviction that here he will get peace of mind to work on innovations of 21st century as very few people generally turn out to the office of the Income Tax!)

When he heard me, he said “Dr Modak, you have come to me at the right time. I have just completed a pilot project on wastewater treatment plant that speaks. Let us drive to one such pilot and you will see that all your concerns regarding treatment plan operations and inspection are resolved” He said this in a triumphant voice.

“Treatment Plants that can speak?” Are you alright Professor?” I exclaimed

In the next one hour, I drove with Professor to an inconspicuous mid-size activated sludge wastewater treatment plant (capacity 2 MLD) near Thane Belapur industrial area. As soon as we entered the gate, the gate greeted us saying “Welcome”. I was shocked to be welcomed by someone not “living” and in a machine voice. Professor smiled and said that he had activated the Speakoscope and now onwards I was going to hear “everybody” at the treatment plan who mattered.

We reached a chamber that had a bar screen with oil & grease trap. Professor saw that the chamber was not well operated and cleaned. A lot of oil could be seen floating and getting across to the next treatment unit i.e. the primary sedimentation tank. Professor asked the OG (“oil & grease trap”) – “how do you feel?” OG said “Terrible, I feel real sloppy. I wish I was given better attention. All I can do right now is skimming but that’s really not effective as there is lot of emulsification. Please tell Manjunath (name of the operator) and his boss to consider using enzymes! Apply them at my friend PST (Primary Sedimentation Tank) downstream. This will reduce the maddening use of chemicals and knock off floating oil and grease”

I was shocked to listen to this experienced and intelligent speech. “How does this oil & grease trap know about advanced use of biotechnology (enzymes)?” And I was still not able to accept the “fact” that the oil & grease trap was actually speaking.

Professor smiled and said that this was essentially a combined application of Human Computer Interface (HCI), biomimicry and artificial intelligence. The main role was however played by Google-Intel microchips. These chips allow the humanoid of each treatment unit to surf on the web for seeking knowledge, upload data and download literature. He said that all treatment units in this plant are fitted with such special chips. I realized that the oil & grease unit (OG) had just smsed Professor the performance data of last 24 hours. Professor was generating infographics out of this data on his iPhone by plotting flow against incoming and outgoing oil and grease concentration. “Hmm” He said to himself.

We moved to the PST.  The PST had lot to say – He said he is not doing well in the removal of suspended solids. He talked about his weir plate –“It is so uneven, tilted and unnoticed. Manjunath keeps loading higher concentrations of alum and lime in despair and this is really not helping much. In fact it is increasing the sludge volumes (swelling effect) and the carryover of high concentrations of suspended solids, oil and grease continues to my friend AT (Aeration Tank) downstream. If we follow OG’s advice on using enzymes with me then we will get benefit of higher removal of both suspended solids and the Biochemical Oxygen Demand (BOD)”

I thought that PST was right. Sometimes, basics like uniform level of the weir plate are not looked into.

PST made other points such as the motor is not regularly serviced and overload alarm does not work.

We moved to the Aeration Tank (AT). AT had four 50 HP floating aerators. When one of the Floating Aerators (FA) saw the Professor, he wobbled a bit and skirted towards the wall and yelled “Hey Professor, long time no see!” Of course only we heard this as we had the Speakophones. When Professor asked FA his point of view, the FA said that he spins generally in the day time, and especially runs in full speed with lot of foaming around when staff from PCB visits. Nights are cool however as no electricity is supplied. “I am quite happy as all of us get a good night sleep. But sometimes one of us is made to spin – just in case” The FA almost winked (i.e. flipped his blade a bit).

I was shocked. Professor was able to “extract” real information on what was happening at the wastewater treatment plant by simply talking to the treatment units. What an intelligent inspection and monitoring technology I thought.

We spoke to the Final Sedimentation Tank (FST), gathered information on the sludge bulking problem and then reached the Final Chamber (FC) of wastewater discharge.

We found FC not very talkative and was kind of evading Professors questions. When Professor asked about the status on meeting with the standards i.e. compliance, FC changed the subject and started talking about climate change (Now a days I have been noticing that if you want to change the topic then most people start talking about climate change – so funny).

“That’s not relevant FC. Come to the point of compliance” Professor growled.

FC said that he cannot speak further as he has got a sour throat.

When we exited the plant and reached my car, I could see that the Professor was visibly upset.

To cheer him up, I told him how impressed I was with his 21st century innovation and how this invention will open up new era of wastewater treatment plant operations, inspections and compliance etc. But Professor was silent. He finally said

“Dr Modak, this is the problem. I have been successful with treatment units like OG, PST, AT, FA and FST, but when it comes to FC, my algorithms and Google-Intel microchips don’t seem to work. Each time I ask FC on his assessment of compliance (as this is the last unit), there is never a true or candid response. Most of the times, FC says that compliance is not a major issue – and it is probabilistic. He often adds that one must keep patience and stay a bit philosophical. And I get really raged”

I sympathized with Professors situation. I also understood why Professors phenomenal invention did not reach the attention of the industries and regulators. (Will it ever?)

I dropped Professor at the office of the Income Tax as he wanted to continue his research.





  1. Great reading. Fantastic style of narration to explain a complex issue of maintainance in an EFT.

  2. Good introduction of optimizing WWTP. Malady of such plants is due to outsourcing .Non-owning of the operation by once own personnel of competence and importance in the organization.PPP has to be demonstrated to make this happen.Rewards have edge over punishment.

Leave a Reply