Saturday, 18 June, 2016




Every new project that comes up in Karnataka, be it a Manufactory, a Residential complex, a Software complex, a Retail Mall, Hospital, Hotel, School, College etc., is required to set up a Wastewater Treatment Plant – A sewage Treatment Plant ( STP) in the case of domestic Wastewater or an Effluent Treatment Plant ( ETP) in the case of process or trade wastes.  That is the terminology used and don’t  ask me why.

This story pertains strictly to the first category of STPs -  Shit and piss.

Every promoter of such projects, not being an expert himself in designing or executing an STP falls back upon a one stop solution for all his woes, and that is his Architect.    The Architect in most cases is only a middle man (Almost all Architectural firms I have had the misfortune to deal with, if only briefly, fall in this category) and brings on board consultants and engineers of various other disciplines required to complete the project which typically will include a :

- Structural Designer
- Plumbing consultant
- Electrical Consultant
- Landscape Consultant
- HVAC Consultant
- Govt. Liaison and commission agent ( much like the Architect himself)

The cost cutting starts at this point when the Architect does not want to employ a specialist Environmental Consultant and asks the Plumbing Consultant to double up and design the STP.  Most plumbing consultants lack the professionalism required to say NO to an assignment they are not competent to handle.  Greed, avarice and the comfort of Google goad them to take on a task that they are just not equipped to handle.  They then end up “ Designing an STP with a little help from Google”  - see my earlier Blog on this subject :

What should be a only a two page concise design brief of an STP containing only pointed and pertinent design basis, design criteria, engineering criteria becomes a big fat tender document with a lot of extraneous crap and totally missing the critical Design and engineering framework.  All manner of STPs are acceptable to this plumber including Septic tanks, Anaerobic systems, UASB, Electrocoagulation Systems, RBC, SBR, MBBR, MBR, EAAS, Enzyme based systems ( ?),  $%#@, and +*%& etc.  Google rather than domain knowledge and expertise is the Friend, Philosopher and Guide for these Commission agents. 

And there is another breed of consultants with Zero technical knowledge who will simply plump for an SBR system simply because “ 99% of STP’s in Bangalore are designed as SBR’s.”


Sitting in judgement over this load of shit and piss generated by the crapsters is a bunch of equally wise men of the TAC constituted by the State Pollution Control Board.  All good men mind you.  I am talking about a bunch more than three years ago consisting of Academicians, retired foresters, fishermen, Agriculturists and suchlike who in all their lives have seen STPs only in these crappy reports. 

In order to show them the real world outside their ivory towers, I took them on a tour of STP’s that they themselves had vetted and approved.  The day tour took them to STPs based on SBR, EADOx, MBBR, MBR - All of them defunct.  In the MBR installation which the team visited ( A self styled Seven Star hotel near Yeshwantpur)  there was a pipeline leading out of the STP transferring raw, untreated sewage directly outside the premises.  So that the STP Operator will not have to scratch his head trying to figure out the Best Operation Procedure ( BOP),  the Pipeline was clearly marked in BOLD LETTERS and in  indelible paint :  “ STP BYPASS”.

Having shown to the TAC first hand their folly in approving all and sundry STP designs of these plumbing consultants, I was hoping for some words of appreciation for having opened their eyes to the pathetic state of the STPs they had approved.  Not just me, thousands of honest citizens in the City would thank the TAC to do their job with due diligence and right application of mind.

Alas ! that was not to be. At the end of the tour, the leader of the TAC team pompously declared that the STPs suffered and were dysfunctional  due to “Poor Operation & Maintenance”.  As a natural corollary therefore no blame should attach to them.  All the STP proposals they had scrutinised and approved were perfect in design and Engineering.

I had to bow my head before these wise men if only to hide the uncontrollable fits of laughter I was breaking into.

Dr. Ananth S Kodavasal                                                                                                June 18, 2016

P.S : I write this piece on the day our Company Ecotech celebrates 30 years of being in the Environmental Control Business. It only saddens me that after all these years neither the Karnataka State Pollution Control Board nor the plumbing consultants have been able to crack the STP Design conundrum.  The lakes of Bangalore suffer on account of these Charlatans.  Honest citizens of Bangalore are destined to suffer lifelong on account of defunct STPs in their backyard.  A perennial source of water for secondary usages is being squandered mindlessly. These quacks must really be put behind bars for professional misconduct and criminal malpractice.  

Sunday, 5 June, 2016



Regular followers of my blogs will no doubt know that I hold Plumbing Consultants in the lowest esteem when it comes to designing a Sewage Treatment Plant.  I have in the past compared them to petty traders on Linghi Chetty Street and Thambu Chetty Street in Parrys Corner, Chennai who would proudly announce themselves to be “ Manufacturers’ Representatives and Commission Agents

Just last week I had occasion to reaffirm and reconfirm this belief of the role of Plumbing Consultants and their incompetence in designing Sewage Treatment plants.

In the first instance this plumbing consultant (who could rightfully claim to be the descendent of a now defunct consulting company of the same ilk)  did a simple cut and paste job of an STP of a Residential Complex to that of a Commercial Complex.  What makes things worse is that the design brief for the Commercial complex clearly states that working hours are only from 8 AM to 6 PM.  Big mistake # 1 !!

Peak sewage inflow hours, Peaking factor etc. are totally different in the case of a Residential Complex and a commercial complex with a canteen attached.  Therefore, Cut and paste is not the appropriate design route to follow.  Big mistake # 2 !!

The Cut & Paste STP of this plumbing consultant was based on the SBR ( Sequencing Batch Reactor) technology, without a proper Decanting mechanism ( Heart of an SBR System), and also not meeting any of the established norms and design criteria for an SBR Design.   Big mistake # 3 !!

Sensing something amiss, the hapless client of this plumbing consultant, a highly respected MNC appointed me to review the Technology selection, Design, Engineering  of the Cut & Paste STP of this Plumber.  This was a job I took up with immense pleasure and glee to completely disrobe the plumber and demolish his pretensions of being an Environmental Consultant and Designer of STPs.  I highlighted several serious faults, deficiencies, inconsistencies in selection of Treatment Technology, design and engineering and sent a two page questionnaire seeking his response.  Two weeks passed, and I got no response from the Plumbing consultant.  On my persistence, the Plumbing consultant sought a Face to Face meeting to clarify matters from his perspective.  Big mistake # 4 !!

Has anybody ever heard of a Plumbing Consultant winning an argument with Ecotech in matters of Technology selection, Design, Engineering, Operation, Maintenance, Resuscitation of defunct STPs ? 

“ When Ecotech Talks, people listen”  is a truism enshrined in Law ( well, almost).

This Plumbing consultant apparently was hoping against hope for a Miracle to happen like the one which saved Brother Dominic of Xerox fame in the blog above.

The Plumbing consultant arrived for the meeting almost an hour later than the appointed time. Big mistake # 5 !!  I suffer from an Obsessive Compulsive Disorder ( OCD) of being on time every time for every meeting, and I expect the same from the opposite party.  The callous behaviour of the Plumbing consultant ( what else can one expect from a common plumber who can only do a cut & paste job) had my blood boiling and baying for his blood all the time I was waiting for him to show up.

Stumbling, stuttering, floundering, facing a bombardment of technical, logical, common sense questions  the plumbing consultant ducked under the Table and a feeble voice was heard saying “ After all Sir, 99% of STPs designed in Bangalore today are based on SBR Technology “

Ah ! How foolish of me not to have understood this novel  99% Theory for Designing an STP !!

Dr. Ananth S Kodavasal                                                                                                June 05, 2016

Saturday, 16 April, 2016



I like the tag line of Café Coffee Day simply because it transforms the humble cup of coffee into an event pregnant with a myriad possibilities limited only by ones imagination.

Which brings me to the point I wish to make about the recent Direction of the bumptious Central Pollution control Board ( CPCB) of India, wallowing in its own self importance.  And why shouldn’t it ?  After all its Parent Ministry the MOEF (originally started off as the Ministry of Environment & Forests) is now derisively called the Ministry of Enjoyment and Fun by several of its own denizens.

The CPCB has promulgated new Rules with respect to quality of treated water from Sewage Treatment Plants ( STPs) across the length and breadth of India – From Kashmir to Kanyakumari and from Assam to Gujarat or vice versa depending on which way your head is screwed on.  It says, and I am not joking, that Ammonia Nitrogen ( NH4-N) and Total Nitrogen in treated water from an STP shall be limited to 5 and 10 mg/L respectively and not vice versa.  I am having some enjoyment and fun from this term vice versa.  I love it.

Now, the new Rule also gives a grace period of a full 5 Years for existing STPs to tremble and obey and comply with the new norms with respect to Nitrogen and its compounds.  Why Five years ?  Well we all know how the mind of  Babudom  works :

- Do we not have Five year plans from the Nehruvian era ?
- Do we not have Governments which last for Five years ?  ( More or less)
- Is Five not a good Odd number ?
- Is Five not a Prime Number ?
- Is Five not half a decade ? 
- Is Five not Fu”nf in German ?

A Lot can happen over Five years in India  !

Well a Babu will be a Babu and will continue to be a BoobooNeither time nor tide has been able to change his inherent DNA.

And my serious question after all the fun and enjoyment, and rolling on the floor is over is simply this :

If the threat of Nitrogen to the Environment is really as serious as it is made out to be, why give Five full years for corrective action ? Shouldn’t it be an imperative and  the Topmost  Priority of the CPCB and the MOEF to have it in place ASAP ?  It all looks like a big joke to me from the jokers having fun and enjoyment at the expense of the common citizens of India.

It reminds me of an old print Advertisement in one of the Env. Magazines :

There is a pall of dense smoke hanging over the entire page.  And a forlorn  balloon which says in a voice almost choking “ If it is the man from the Dept. of Environment, tell him I can’t see him now”. Well said -  Avoid these folks like the Plague !

Dr. Ananth S Kodavasal                                                                         April 16, 2016

Wednesday, 13 April, 2016



Like the story of the visionary businessman Srihari Khoday from some 25 years ago, here is another real life recounting of my brush with another equally business minded agency – the Bangalore Water Supply & Sewerage Board, fondly called the BWSSB :  With some officers of the Board, to be more precise.

As a very strict rule, I do not entertain requests for my services from Governmental Agencies, Parastatals, Govt. undertakings etc., for reasons well known to those who may have had the misfortune to deal with these rascally entities.

About 20 years or so ago the BWSSB came to the happy conclusion that it could not handle the K&C Valley STP ( the one behind the Karnataka Golf course ) satisfactorily enough with its own resources of men and materials.  A decision was therefore taken to entrust Operation & Maintenance of the STP to private hands.  A very laudable decision by all counts no doubt - but for one deal breaking consideration which I was about to discover.

I was pushed, sweet talked, persuaded and cajoled to pick up this tender by a very close associate of mine at that time with the solemn assurance that it was for the greater good of the society and for the benefit of the long suffering Bellandur lake which was at the receiving end of Millions of litres of sewage from half of Bangalore city.  Also, the BWSSB officer in charge of this exercise was a long time friend, a class mate of his from school and college days.  Despite initial reluctance and nervous trepidation that I felt, I steeled myself to venture into hitherto uncharted territories : If Captain Kirk and his crew of Starship Enterprise can do it, so can I.

I studied word by word, para by para and page by page the tender document until I could recite the tender backwards. This method of dissecting a tender document  to the last comma and full stop was drilled into me in my first job in India with Dorr-Oliver Inc. immediately on my return from the USA.  And as prescribed in Section 3.5 of the Tender document, I visited the  STP for the customary site inspection.  From more than a  Kilometer away on the lonely Wind Tunnel Road,  I was unerringly guided to the spot by the ever increasing stench of untreated sewage. No google map was required to home in to this STP.

The STP itself presented a picture of a major disaster struck area.  Dismantled and stripped down pumps and forlorn motors strewn around helter skelter ; Sewage overflowing from channels and drains, with swarms of mosquitoes proliferating in this happy breeding ground ; Less than 30 % of Surface aerators which deliver Oxygen to the bugs which treat sewage, churning the surface of tanks, which in itself was a minor miracle.  There was not a single human soul in sight.  I beat a hasty retreat from  this unholy hell hole, now firmly determined that no amount of pushing, sweet talking, persuasion or cajoling will make me participate in this tender.

The final kick in my ass for this crazy adventurism was delivered by the BWSSB classmate himself who took me aside and gently broke to me the unwritten clause and condition of the tender for privatisation of O&M of the STP.

Apparently the STP generated a lot of organic sludge from its settling tanks which were the only units which worked in the STP,  and  which was good farmland manure.  And in those days, when Bangalore city was not the urban conglomeration and concrete jungle that it is today, there were farmlands and farmers in close vicinity to the STP.  These farmers paid Rs. 400 per tractor load to take away the manure for their use.  The total amount per day thus collected ran into several thousands of Rupees.

The classmate from the BWSSB then assured me that the only Service Level Agreement they would hold me to was that the entire proceeds of sale of organic manure from the STP should be off the books and passed back to the officers who were good enough to make the privatisation exercise happen.  There was no further requirement from the STP and no questions asked.  Bellandur lake be damned.

Three cheers for a Happy New Year  and all hail Privatisation – BWSSB style.

Dr. Ananth S Kodavasal                                                                                                April 14, 2016



This Commentary is a rejoinder to a recent Notification from the Karnataka State Pollution Control Board revising standards for quality of treated sewage.  More specifically the KSPCB has introduced NH4-N ( Ammonia Nitrogen) and Total Nitrogen and set limits of 5 mg/L and 10 mg/L respectively for these parameters in treated domestic sewage.  The new standards are made applicable to all STP’s including those in Residential Apartment Complexes, Commercial Complexes and the Large STP’s of Urban Local Bodies ( ULB) such as City Municipal Corporation, Town Municipal Corporation etc. in Karnataka. 

The KSPCB  takes refuge under the plea that the Notification has been issued following a Direction from the Central Pollution Control Board – Delhi ( CPCB ) dt. 21-08-2015 to enforce these new Rules.

Let me explain why I feel both agencies, and the KSPCB in particular have missed the Wood for the trees and why this is a Knee Jerk reaction similar to several others which we have now come to expect from such “Expert” bodies constituted by the Government.  Md. Bin Tughlaq would have been immensely pleased to have such worthies in his Durbar.

1. From a reading of the brief narration given of the CPCB Direction, it is clear that the Rules must be made applicable to Large STP’s of ULB’s and not to distributed , decentralized small, mini and micro STP’s in Residential apartment Complexes.

2. Has the KSPCB got any expert technical opinion or has it conducted any public consultation before applying the Rules across the board to all STP’s ?

3. Has the KSPCB done even a cursory study on the technical and practical feasibility of enforcing these Rules in the Micro and Mini STP’s ?

4. Has the KSPCB explored other alternative technologies, methods and means of reducing Nitrogen pollution in the lakes and water bodies ?  Is Nitrogen control in the STP at great cost, expenditure of energy and chemicals the only solution ?

The Answers to all these questions can only be a resounding NO. 

Here is an alternative method  to beneficially harvest Nitrogen in sewage and make money instead of pouring money down the STP drain.

About 25 years ago, I was summoned by Sri. Srihari Khoday, the liquor Baron of the day in  Karnataka to study  treatment plants in their breweries and distilleries.  When the main discussions concluded, as an aside, Mr. Khoday asked me for my opinion on the technical feasibility of harvesting Water Hyacinth ( Eichhornia Crassipes) on a commercial scale from lakes in Bangalore, more particularly Bellandur ( Yes – Bellandur was polluted even in those days).  Water Hyacinth takes up huge quantities of Nitrogen and phosphorus for growth and becomes biomass which then can be anaerobically digested to generate Methane and energy therefrom and supply power to nearby industries. The largest consumer in the vicinity was Hindustan Aeronautics Limited ( HAL).  Twenty five years ago, this struck me as a revolutionary idea, and out of the box thinking of a visionary businessman with great commercial acumen.

Maybe the Babus in  those days were equally insular to practical ideas and solutions as they are even to this day : Srihari Khoday’s idea could not find wings to take off.  I have myself proposed very economical, practical and executable solutions to resuscitating defunct STP’s in Bangalore to all the authorities in the Government directly concerned.  Needless to say, they have fallen only on deaf ears.

Dr. Ananth S Kodavasal                                                                                      April 13, 2016


Water hyacinth, Eichhornia crassipes, growth and nutrient uptake rates, as influenced by different N sources and N transformations, were measured using microcosm aquaculture systems. Net productivity was highest in the system receiving equal amounts of $NH_{4}{}^{+}$ and NO3 - (at 10 mg N l-1 each) and decreased in the order of NO3 -, $NH_{4}{}^{+}$, urea (added at 20 mg N l-1 each), and methane digestor effluent (at 6 mg N l-1). During the first 7-wk study (average ambient air temperature was 26-28°C), biomass yields were in the range of 19-53 g dry wt $m^{-2}\ day^{-1}$, while between the 8th and 12th wk (average ambient air temperature was 16-22°C), biomass yields were in the range of 10-33 g dry wt $m^{-2}\ day^{-1}$. In the systems with either $NH_{4}{}^{+}$ or NO3 -, or both added in equal proportions, about 14-20% of the total yield was contributed by roots, whereas in the system with urea and digestor effluent, roots contributed about 23 and 44% of the total yield, respectively. Nitrogen and P uptake per unit area followed trends similar to biomass yields. Nitrogen uptake rates were in the range of 533-2,161 mg N $m^{-2}\ day^{-1}$ for the systems receiving $NH_{4}{}^{+}$, NO3 -, and urea, while uptake rates were in the range of 124-602 mg N $m^{-2}\ day^{-1}$ for the system receiving methane digestor effluent. Phosphorus uptake rates were found to be in the range of 59-542 mg P $m^{-2}\ day^{-1}$. Under the most favorable conditions, maximum recorded biomass yield was 53 g dry wt $m^{-2}\ day^{-1}$, with N and P removal rate of 2,161 mg N $m^{-2}\ day^{-1}$ and 542 mg P $m^{-2}\ day^{-1}$, indicating the potential of water hyacinth to produce large amounts of biomass which can be potentially used as a feedstock to produce methane.

Economic Botany © 1983 New York Botanical Garden Press

Sunday, 18 October, 2015



Between October 10–17, 2015, I was in Bangladesh.  The longest sojourn so far in my 3 years of association with the PRAN-RFL group, one of the largest and highly respected business houses in Bangladesh.  The trip was to review performance of nearly 6 ETP’s already installed by us for our Associate and to inspect ongoing construction and commissioning of 3 more ETP’s at different factories and locations across the country.  And to visit the site of a proposed ETP for a new milk collection and chilling centre, and which in a few years will be converted to a full fledged Dairy.

A trip which took me from Dhaka to Natore – Shazadpur ( Rabindranath Tagore is revered here)  – Dhaka – Habigonj – Palash – Ghorasal – Kaligonj - Dhaka

A hectic schedule which culminated on a Friday afternoon with a presentation to over 30 officers of the PRAN –RFL group directly/ indirectly connected with the ETP’s, gathered together from the various factories and the Head office.  This final meeting was at  the Mymensingh Agro Ltd. Conference room in the RFL Industrial Park ( RIP) at Kaligonj right on the bank of the Shitolakkha river.

Here are some snippets of information, musings if you like about the wonderful city of Dhaka and our neighbor – Bangladesh. These were earlier posted serially on facebook during my stay in Bangladesh


Had by far the best, most delicious sweet lassi at The Aristocrat Restaurant on National Highway N4 to Natore, near the iconic 4.8 Km long Bangabandhu Sethu bridge. Pure Mishti Dhoi whipped up with extra cream, a hint of Bashundhi, served in a tall glass, cold and thick. Very thick. So thick you could float a dollar coin on it ( to borrow a phrase from Louis L'amour).


Yet to see a Rickshaw, car, bus or truck that has not been scratched, scraped, dented, bashed up or otherwise seriously abused. Police and army vehicles are the only exceptions. Not surprised.


An overwhelming majority of trucks in BD are Tata, Eicher, Ashok Leyland in that order. All the buses are Hino from Japan. What makes trucks from India competitive but not the buses ?

Got the answer from  Vivek Annaswamy, My uncle who retired from Tata Motors as Chief Executive from  after decades of service in that company at various locations and in various functions :    “  Comfort level. Here ( In India)  we make Buses from Truck chassis. Order of the day are Low floor Monocoque buses “


Lunch at Pizza hut in Dhaka today. Pepperoni and cheese : All beef, no Pork. And in India the same Pizza comes with pork - No beef. Would love to let loose our worthy politicians on this one.


If you finish your commute in Dhaka at an average speed of 5 Kmph, you have zipped thru the city. Compare this with the greased lightning speed in Bangalore of 8 Kmph !


 Some interesting statistics from BD  :

- 87 % of the Nationals are Muslim- 12 % of the Nationals are Hindu- 1 % of the Nationals are Buddhist- 0.5 % of the Nationals are Christian- 100 % of Bus drivers are Insane

To which my good friend Devinder Singh from Frankfurt observed : 87+12+1+0.5 = 100.5% !!!

And my Riposte : 

May be this is the reason they say BD is overpopulated 


We left Habigonj in the far North East of Bangladesh late in the evening at 5.30 PM.  The sun sets early in these parts. With the Sun calling it a day, emerald green paddy fields on either side of the Highway fade to grey in the distance as a thin gossamer mist hangs over them gleefully proclaiming that every sun has to set.


New experience today.  Factory hopping from Pran Industrial Park (PIP) to Pran - AMCL factory to RFL Industrial Park (RIP) by speedboat on the Shitalokkha River. All on account of a blocked road connecting the factories. Mercifully no traffic jams on the river.  And to beat the afternoon heat, travelled standing to catch the onrush of heady river air.


Half the trucks and minivans plying on arterial roads, streets, lanes and bylanes of Dhaka carry a placard “ On Emergency Export Duty “.  There are ululating ambulances and police vehicles. A myriad cycle rickshaws darting, dodging, weaving and squeezing their way from lane to lane.  Pedestrians crossing wide boulevards chock a block with traffic seeking safe passage with upraised palms.  And the private vehicles which although do not carry any placards, are for all intents and purposes “On Emergency Personal duty”.  Here Nobody gives way to anyone or anything.  Refreshing to see no VVIP culture here.  Would love to plonk our own Chandrababu Naidu and Chandrasekhar Rao in Dhaka traffic.


Every time I visit the factories of the PRAN – RFL group, may be after every 6 months or so, It never fails to amaze me the changes I see in these units.  Old gives way to new, new constructions everywhere, technology upgradation, modernization of machinery, new products, backward and forward integration and constant expansion. Never seen anything coming close to this kind of frenetic activity even in designated industrial Areas in India : Just the scale of it is mind boggling.


From the time they paid a hefty fine to the Bangladesh Department of Environment in early 2002 for polluting the Shitolakkha river, PRAN group has made tremendous strides in its environmental control activities.  All the factories along the river now have scientifically designed ETP’s running well, as in their other factories in Bangladesh.  There is a high level of awareness which is now widespread in the group and its officers about their environmental responsibility, and a good working knowledge of the treatment processes in ETP’s.  A remarkable achievement in such a short period of time.  It took almost a couple of decades I reckon for a similar transformation to happen in India.

Dr. Ananth S Kodavasal                                                                        October 18, 2015

Sunday, 4 October, 2015



Regular followers and readers of my blogs would have no doubt read the piece about an STP titled  “Designing by the Book”.  In keeping with advancement of technology, here is an STP proposed to be designed with a little help from Google.

Many well wishers have often asked me why I do not respond to RFQ’s ( Request for Quotation) for STP’s floated by Architects and their Plumbing Consultants. I present to you below a recent RFQ I came across for a High end apartment complex of a Grade I Builder sent out by a leading Architect and his Plumbing consultant.  The specifications for the STP in the RFQ will accept  anything from a SIPANI BADAL three wheeled car to a PORSCHE 911 and everything in between if I were to borrow the equivalent from the automobile world.

Under the circumstances, dear reader you will agree that the odds of a snowflake in hell are infinitely higher than Ecotech ( our Company) landing a contract through this tender route.

The following is a true, entirely authentic and unedited extract from an RFQ we were regaled with from a respected Architectural firm in Bangalore.  The only camouflaging I have done is to the names of the actors in this farce and some figures to protect their identity and their good name ( although I am not entirely sure why).  The camouflaged bits are in red font by me..




Date  : Does it really matter for this kind of trash ?
Client: M/s. YYYYYYYY ( same as above)
Architects:  ZZZZZZZZ ( In sleep mode)
PHE Consultants: 000000000.... ( Not enough zeroes in this world for ranking)


The proposed project is a residential Apartment located  Anywhere in Bangalore comprising of 999 Flats with common amenities like clubhouse, Gym & swimming pool etc.
The total water requirement is as mentioned in the below table.

No. of Flats
No. of persons per  villa
Water Usage per person per day
Water used for domestic uses
Design factor for additional reserve capacity

Additional reserve capacity
Total Flow in ltrs/Day
Total Design Capacity of Plant
The project is a gated community which has no access to sewer system hence requires establishing a STP onsite. Further it is also envisaged to use the reclaimed water for landscaping by spray or drip kind of irrigation system and if need be for flushing in future.

Plant design parameters:

Influent to the STP shall be domestic sewage generated in the Flats and common amenity areas, an approximate characteristics of the likely expected sewage is given below. The influent sewage parameters may vary time and season, the plant shall be capable of accommodating organic loading to the tune of 30% and a hydraulic shock load of 30 to 40% with minor operational adjustments.

Inlet (Expected)
Outlet (Required)

BOD, ppm
COD, ppm
TSS, ppm
Oil & Grease, ppm
6.5 - 8.5
6.0 - 9.0
Residual chlorine, PPM
<1 mg/lt
1 mg/lt

The expected outlet water requirements shall be met by the plant while operating in the range up to the designed capacity. The output performance shall not vary by more than 20% under shock loads.
The output is to be treated as 50% for reuse and 50% for landscaping quality water generation.

Sewage treatment processes:

The vendor may select any process as per their area of expertise / proprietary design. The vendor shall submit a detailed process description and flow sheet considering the site conditions.
The vendor may also choose from the list of available methods for treatment or propose any other alternative.

Biological:  Aerobic
  • Extended aeration
  • SBR (Sequential Batch Reactor)
  • FAB (Fluidized Aerobic bed)
  • SAFF (Suspended Aeration Fixed Film)
  • FBBR (Fluidized bed Bio Reactor)
  • RBC (Rotating Biological Contactor)
  • MBR (Membrane Bio Reactor)

Biological Anaerobic systems
  • UASB
  • Septic tank

Physical / Chemical:
  • Enzyme activated treatment
  • Electrolysis

The sludge generated in the STP shall be suitably treated to ensue that it can be properly disposed along with municipal solid waste. Sludge drying beds are not permitted. Sludge volume reduction by aerobic / anaerobic digestion in small plants are not viable hence the same may be considered for plants above 250 kld.

The vendor shall also furnish detailed design calculations along with the offer which shall be scrutinized by the PHE consultants. In the event of the vendor not willing to share the design calculations they shall guarantee the performance of the system by a Bank Guarantee of a value as per the client discretion and shall be decided based on the vendors reputation and the performance of the existing plants.

NOW SOME PERTINENT OBSERVATIONS AND QUESTIONS FROM ASK ( that is me : of      “ When Kodavasal talks, people listen” fame)

( Pls. note I have overlooked and condoned some minor lapses in this document which may have crept in due to a mindless cut and paste job done by the Consultant : Ex : “No. of persons per villa”.  Is this not an apartment ?)

1. Since when has Karnataka State Pollution Control Board ( KSPCB)  relaxed its Rules and left toilet use option of treated water to the discretion of the plumbing consultant ?

2. What can be the seasonal variation in the characteristics of domestic sewage from an apartment complex ?  Due to variations in Temperature ? The monsoons ? Seasonal changes in dietary pattern of the residents ?

3. Why must the STP accommodate and handle only 30 % of the organic load ? Why not 100 % ?  And where does one offload the balance 70 % ?

4. 30 – 40 % of excess Shock loads are better handled by proper Design and Engineering  of the STP rather than by twiddling with some unspecified and abstruse  “minor operational adjustments”

5. Obviously the Consultant is not wise to the KSPCB “ Urban Reuse Standards” for quality of treated water enforced now for more than 6 years, and has prescribed his own set of standards.

6. I fail to understand the grammar of the consultant’s 50 % for Reuse and 50 % for landscaping jargon.  In Technical papers and documents one expects exactitude and precision and not vague descriptions.

7. About the wide choice of STP technologies left to the bidder, less said the better.  One wonders however at these possibilities and has these nagging questions :

  -  Had there been a more powerful search engine, say Google +++,  would the list have been longer ?

- Does the Consultant possess adequate knowledge, competence, skill and expertise to assess the pros and cons of the various technologies that may be proposed by sundry bidders.  And if the answer is YES,  why has he not done this exercise and homework himself and Zeroed in on the one most Optimal and Practicable technology option for an STP of this size in this setting ?

- Under the Biological aerobic options, what is the difference between an FAB and FBBR ?  Am I missing some key but obscure differences in Design and engineering between the two competing technologies ?

- A septic tank option for a 230 KLD STP ?????

… and so on.  Professional  etiquette and decency prevents me from completely disrobing the consultant.


My Company steadfastly refuses to participate in such open tenders for precisely the above reasons.  What chance does a good STP with proper scientific design and engineering features have against these odds and at the hands of an incompetent consultant ?

Dr. Ananth S Kodavasal                                                                        October 04, 2015
Director – Ecotech Engg. Consultancy Pvt. Ltd.
Bangalore 560 066

Mob : 98450-62033