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O&M is the Achilles Heel of STPs

Oftentimes we are asked by our clients why our operation & maintenance (O&M) charges for a biological wastewater treatment plant (WWTP) also known as an STP are higher than some of our competition.

Why does Ecotech have to employ an environmental engineer, a field officer, a quality & training officer, a mechanic, an electrician, a logistics officer, as part of the backend support team for an STP? Doesn’t the STP already have a sufficient number of on site dedicated and trained operators, deployed in three 8-hour shifts? Why do you have a proprietary training regimen for these individuals – after all, isn't running an STP an unkilled or semi-skilled job?

The cost of the support staff and our proprietary systems to ensure quality control add to the Annual Maintenance Contract (AMC) cost, which makes Ecotech’s charges to be higher than other lesser agencies in the business. Can these staff then not be called upon on a need basis from time to time, rather than on a routine monitoring basis, whether there is a need or not?

These questions seem quite logical coming from a client whose objective is also to minimise STP AMC costs.

Our questions right back to the client — would you rather pay 50% and have 0% performance, and thus be able to reuse nil? Would you rather your STP operator just "settled things" with the concerned officials and let you go your merry way? Would you rather continue to pay Rs 100-150/KL for your freshwater needs, when you could use STP-treated water for free? Would you want your end users to take photos of black particles and discoloration in toilet flush water and plaster it all over Facebook and Insta, tagging you in the posts for good measure?

Penny wise, pound foolish.

Do you wait for your car’s engine to blow a head gasket, leaving you stranded on the road with a hefty repair bill, or do you proactively get routine service done such as an oil change or an engine coolant flush?

This post will enunciate Ecotech’s philosophy of O&M of a biological WWTP in some detail, and demonstrate to you that we are in fact the most cost-effective in the business. Our well-established proprietary best practices for O&M ensure that your STP doesn’t go kaput leaving you with foul odours, compliance fines, and having to tanker in clean water at exorbitant rates to meet your secondary water use requirements (watering the grounds, flushing toilets, car wash, etc.). And worst of all loss of reputation.


As Prof. W Wesley Eckenfelder Jr., that giant of industrial wastewater treatment, used to often remark, biological wastewater treatment is an art, not science. If this were not the case, then an STP could be fully automated, and there would be no need for even the three operators on site. The STP and the bugs (microorganisms that digest and clean up the effluent) in the STP can then merrily go about their business, with suitable instrumentation and control systems. Almost zero cost of O&M. Sounds fantastic?

Fantasy it certainly is.

The most sophisticated WWTPs in the world, which have a high level of automation, in fact have a large complement of dedicated on-site staff to constantly monitor all these systems. Check out this video which talks about Chicago’s municipal wastewater treatment plant, which is the biggest WWTP in the world. High levels of instrumentation and automation, but a substantial, well-qualified workforce present 24/7, including dedicated on-site testing labs with scientists, to support and monitor this plant.

And don't even get us started on AI (Artificial Intelligence) and ML (Machine Learning). Terms being bandied about by snake oil salesmen. Talking about Artificial Intelligence to control STPs is putting the cart (way way) before the horse. These so-called AI models are nothing but dressed up if/then statements hard-coded with scant knowledge of the underlying physics of the system. You don't need AI to tell you that your plant is not working! And of course (this supposed) AI is going to do you no good if your delicate biological system is completely out of whack.


The three cardinal laws for successful, satisfactory performance of an STP or WWTP on a sustained long term basis are:

- Proper Design

- Proper Engineering

- Proper O&M

These three attributes are mutually exclusive, and equally important. For instance, a poorly designed plant cannot be made to perform miracles through superior O&M practices. Likewise, the best designed and engineered plant will go defunct quickly with poor O&M practices, racking up exorbitant daily costs.


Overriding all of the three attributes above, the overarching principle—we call the Zeroth Law—that determines the success of a WWTP is selection of the Most Appropriate Treatment Technology from the dozens of good, bad, and ugly technologies bandied about, that Google will obligingly, mindlessly spew out. Lesser consultants and fly-by-night operators employ this naïve method (design by Google) for WWTP design. Ecotech on the other hand has been in this business for over 30 years, and let us assure you that we are here to stay.


STPs and Effluent Treatment Plants (ETPs) based on biological reactions employ single-celled and tiny multicellular microorganisms. These are living beings which do the purification job in an STP. Being extremely tiny (weight does matter here), even the slightest disturbance from the normal can affect their health and therefore their performance. For example sudden variation in temperature or pH, shock load, entry of a foreign material (say excessive oil, detergents, or certain chemicals from medications flushed down the drain), drop in air supply due to a malfunctioning air blower, feasting (overload of effluent), fasting (underload), and any other such disturbances can potentially decimate the microorganism population within the STP, resulting in total failure. Humans on the other hand are less sensitive to such changes in external stimuli thanks to our large body weight. All these are lessons from elementary microbiology.

Once these microorganisms and bacteria fall sick, it takes about 10-15 days to nurse them back to good health and restabilise the STP. This scenario is totally unacceptable. Therefore the key to successfully operating and maintaining a biological STP is to proactively anticipate any disturbances/malfunction in either the process or the electromechanical systems before they occur. This is done by carefully monitoring the pulse of the STP and taking necessary preventive measures proactively.


And then there are the operators at site who can also malfunction. After all, they are humans. Lack of adequate motivation, idle time (devil’s workshop), 12-hour shift practices by lesser agencies (Ecotech will never accept or allow 12-hour work shifts), absenteeism, wandering out of the STP etc., can cause serious damage to the plant. This is why our field officers are critical. Their job is to make rounds of the various STPs under our care, to ensure operator accountability and support them as needed.


Each of our backend support staff have clearly demarcated functions, but they work in complete coordination to ensure proper running of all the STPs under our aegis. Our support staff is comprised of mechanics, electricians, field officers, environmental engineers, a quality & training officer, and a logistics officer (for timely supplies of spares and consumables). The operators on site are simply our eyes, hands, feet, and ears to operate the STP following a standard operating procedure and report to us any deviation from the normal.

No other agency in Bangalore, or indeed in India has mastered this art of O&M to the levels that we at Ecotech have achieved. Ecotech sets the benchmark for best practices in O&M which many lesser agencies try to follow, but fail miserably due to lack of trained, experienced, dedicated staff with adequate knowledge and skills. More importantly they fail because of their lack of long-term vision and commitment to excellence and integrity.


This philosophy of O&M of an STP is what sets Ecotech apart, head and shoulders above the competition, if one can even consider them as such. Rest assured that we will provide you with the most cost-effective and sustainable solution out there.

We are there with you for the long haul.

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