68. AN STP IN THE TOWN OF KUPPAM ( Pop. 21,963 Census 2011)
This little story again illustrates and highlights the fact that I have been repeating again and again and again : The classical Extended Aeration Activated Sludge ( EAAS) system is still the best STP Technology for Micro , Mini and small STP’s in Res. Apt. complexes, Commercial Office complexes, Hospitals and colleges etc.
The small little town of Kuppam best categorized as a Tier 4/ Tier 5 town, lies in the neighbouring state of Andhra Pradesh, roughly 130 Km ESE of Bangalore. It can be reached in about three hours by car on fairly well tended roads. I had occasion today to visit this little town on an invitation from the prestigious PES group of Institutions which runs a Medical college and a Hospital attached to the college in Kuppam.
My brief was to inspect, study and solve the riddle of excessive loss of water in their Water Treatment Plant ( WTP) in excess of 30 % when nearly 600 KLD of water extracted from their borewells was treated through a Pressure Sand Filter and a water softener. Sitting in Bangalore, my first thought was that the Ion Exchange resin in the softener may have outlived its usefulness and therefore was calling for frequent regeneration with common salt, followed by rinse operations which might explain the losses. However, as is my wont, I reserved judgement until I did a Genba walk and an onsite physical inspection.
The puzzle was solved easily enough within minutes when the WTP operator at site confessed that he did a backwash of the sand filter once every three hours for 20 minutes on each occasion, which water was then wasted out on to the adjacent open Field. This practice was based on some Standard Operating Procedure ( SOP) possibly shared with him by the very same ignorant Plumbing Consultants whom I deride at the slightest chance that I get.. I showed the operator the quality and clarity of this “Backwash Waste” and his folly in blindly following a fool’s advice and gave him a fresh set of SOP based on scientific principles of pressure loss across the filter measured by two pressure gauges one fitted before and one after the filter. The small town boy was beaming with pleasure, nodding his head at this simple, logical, common sense explanation when I left him to inspect the Sewage Treatment Plant on the other side of the campus.
Not one, but Two STP’s I was told were on campus, one rated at 200 KLD and the other at 400 KLD. Having seen first hand sins of the past in the WTP, I trudged along towards the STP’s, expecting the worst.
LO and Behold ! Both STP’s were in perfect working condition, each receiving also the design quantity of wastewater and producing treated water of excellent quality like from any STP that we at Ecotech operate and maintain. The secret of this Success was not far to seek. Both STP’s were built on the Classical EAAS Technology, well designed and engineered.
In a remote Small Little Town of Kuppam I saw a 100 % success rate of STPs. If only the self proclaimed Hi tech City of Bangalore had this success rate, the lakes in Bangalore would not have to suffer. For this to happen, one must cull out and permanently disable all commission seeking Plumbing consultants in Bangalore and the equally corrupt Architects who employ them
This story of Kuppam would be incomplete without a final piece of teaching and learning.
When I asked the Boy how many times he backwashed the Filter in the STP, he very respectfully replied that he did this procedure two times in a day. Where was the need then to backwash the filter in a WTP every three hours I questioned him, when you are filtering clean water from a borewell and not STP water ?
Good Environmental Engineering as I have often said is only 50 % knowledge, expertise and experience. The other 50 % is the use of common sense to apply in practice what you have learnt.
Dr. Ananth S Kodavasal May 18, 2018