Why cutting corners in STP maintenance will cost you dearly

June 2, 2018

Oftentimes we are asked by our clients why our operation & maintenance (O&M) charges for a biological wastewater treatment plant (WWTP) or 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, and 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? 


The cost of the support staff adds to the Annual Maintenance Contract (AMC) cost, which results in Ecotech’s charges being higher than those of 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.


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 established 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.).




To quote Prof. W. Wesley Eckenfelder Jr., that giant of industrial wastewater treatment—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, right? 


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 staff who 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. Skip to 4:12 in the video to learn about the role of microorganisms that do the treatment.



Impressive levels of instrumentation and automation, but an equally impressive, well-qualified workforce present 24/7, including dedicated on-site testing labs with scientists, to support and monitor this plant.




The three cardinal laws for successful, satisfactory performance of an STP 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 an STP is selection of the most appropriate treatment technology from the dozens of good, bad, and ugly technologies bandied about, that Google will obligingly and mindlessly spew out. Lesser consultants and fly-by-night operators employ this naïve method (aka design by Google) for STP 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.




Did you catch the part in that video (at 5:15), where the Environmental Microbiologist at the Chicago wastewater treatment plant says that there are some things that cause their process to go "whacko"—like somebody illegally throwing a slug of cyanide into the drain, killing all the bacteria and protozoans in their plant? To avoid this they proactively monitor the populations of the various microorganisms in the plant.



STPs based on biological reactions employ single-celled and tiny multicellular microorganisms. These are living beings which purify the water 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, a sudden variation in temperature or pH, shock load, entry of a foreign material (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, which is food for the microorganisms), fasting (underload of effluent), 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 extremely costly, and 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 on site who can also malfunction—after all, they are humans. Lack of adequate motivation, idle time (devil’s workshop), tiring 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 the rounds of the various STPs under our care, to ensure operator accountability and support them as needed.




Each of our backend support staff has clearly demarcated functions, but they work together in complete coordination—much like a well-conducted orchestra—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, ears, hands and feet 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 the lack of dedicated staff with adequate knowledge and skills.


More importantly, they fail because unlike us, they lack long-term vision and a commitment to excellence and integrity.




Our 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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