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In India, where rapid urbanisation meets unpredictable monsoons and growing water stress, Sewage Treatment Plants (STPs) have moved from being an optional facility to a non-negotiable requirement. From residential townships in Gurugram to five-star hotels in Goa, hospitals in Chennai to labour colonies near Pune, every new project now needs an approved STP plant before it gets an occupancy certificate.
Yet, despite clear mandates from the National Green Tribunal and state pollution control boards, many builders, facility managers, and even architects still hesitate. The reason? A long list of half-truths and outdated beliefs that make STPs sound complicated, expensive, and unnecessary.
Let us examine some of the most persistent myths surrounding Sewage Treatment Plants and replace them with realities that thousands of SKF Elixer customers across the country already experience every day.
Myth 1: “STPs are basically glorified septic tanks that only dilute sewage”
This is perhaps the oldest misconception. Many people believe that an STP simply collects sewage, lets solids settle, adds some chlorine, and releases slightly cleaner water.
Reality: Modern STPs, especially those based on Attached Growth Bioreactor (AABR) technology, work on advanced biological principles. Specially designed plastic media inside the bioreactor tanks provide enormous surface area — sometimes over 200 m² per cubic metre — for beneficial bacteria to grow as a thin biofilm.
As sewage flows past this biofilm, microorganisms play a crucial role in consuming organic matter, breaking down harmful pathogens and other wastewater contaminants, and even reducing nitrogen compounds through natural nitrification-denitrification.
The result? Treated water that consistently meets or exceeds CPCB norms for pH, BOD below 10 mg/L, COD below 50 mg/L, and total suspended solids below 20 mg/L. In many cases, the output is clear, odourless, and safe enough for direct reuse in flushing, gardening, or cooling towers.
Myth 2: “Treated sewage water is never truly safe — it always smells and looks dirty”
Walk past any poorly maintained 15-year-old STP and you might agree with this statement. But that is a problem of design and operation, not technology.
Reality: A well-engineered STP using stainless steel tanks and AABR media produces water that is visibly clear and completely odour-free. At several installations — from a 150 KLD plant to a 50 KLD unit — maintenance teams use the treated water for landscape irrigation without a single complaint about colour or smell.
Independent NABL laboratory reports regularly show faecal coliform counts below 100 MPN/100 ml, making the water safer than many municipal supplies during monsoon months.
Myth 3: “Running an STP means sky-high electricity bills and constant maintenance headaches”
Fifteen years ago, when most plants in India were conventional activated sludge systems, this was partly true. Blowers ran 24×7, sludge had to be removed every few weeks, and operators were needed round the clock.
Reality: Today’s AABR-based plants like the SKF Elixer Vulcan STP operate on a completely different principle. Because bacteria grow attached to fixed media instead of remaining suspended, the system needs far less aeration energy. Actual power consumption usually falls between 0.8–1.2 kWh per cubic metre of sewage treated — translating to roughly ₹8–12 per 1,000 litres at commercial tariffs.
Sludge generation is 30–40 % lower than older technologies, meaning de-sludging tankers visit only once every 18–24 months instead of every 3–4 months. Many of our fully automatic 50–200 KLD plants run happily with just one part-time technician visiting twice a week for basic checks.
Myth 4: “STPs are only meant for giant factories or million-square-foot townships”
Pollution control boards have minimum thresholds, so many smaller project owners assume they can skip proper treatment.
Reality: Compact, modular STPs are now available from as small as 5 KLD capacity — perfect for farmhouses, boutique hotels, clinics, schools, and even large independent bungalows in cities like Bengaluru and Delhi where groundwater levels are falling fast. SKF Elixer’s Vulcan series starts at 5 KLD and scales in 10–25 KLD increments all the way to 500 KLD, using identical stainless steel construction and AABR technology across the range.
A 30-room resort and a 75-bed hospital can both run 25 KLD Vulcan units in their basements without any space or noise issues.
Myth 5: “Once you install an STP, you are stuck with it forever — no flexibility”
Traditional civil-constructed plants are indeed permanent concrete structures. Shifting or expanding them is a nightmare.
Reality: The Vulcan STP range is factory-fabricated in corrosion-resistant SS-304/316 tanks that can be unbolted, transported, and reinstalled at a new location in under two weeks. Several of our clients — construction companies working on phased projects and event organisers setting up temporary labour camps — have moved their 50–100 KLD units three or four times over the past decade without any loss of performance.
Myth 6: “Treated water reuse sounds good on paper, but nobody actually does it”
Visit any water-scarce city and you will see the opposite happening on a large scale.
Reality: A 200 KLD Vulcan plant supplies flushing water to 1,400 apartments, saving over 80,000 litres of municipal/tanker water every single day. A commercial tower uses 120 KLD of treated water for cooling towers and irrigation, cutting their freshwater bill by nearly ₹18 lakh per year. Even in smaller setups — 40 KLD at a Jaipur hotel — treated water keeps the 3-acre lawn green throughout summer without touching borewell water.
These are not pilot projects; they are commercial installations running 24×7 for the last 4–8 years.
The Bottom Line: An STP Is Now a Smart Business Decision
In 2025, installing a properly designed Sewage Treatment Plant is no longer just about compliance. It is about protecting your project from future water price shocks, earning green building points (IGBC, GRIHA), enhancing property resale value, and genuinely contributing to water security in your city.
With power-efficient, low-sludge, odour-free technologies now available in compact stainless steel packages, most old objections simply do not hold water anymore.
If you are planning a new residential, commercial, hospitality, or institutional project anywhere in India, the question is no longer “Do I really need an STP?” but “Which STP will give me the best long-term value and peace of mind?”
Frequently Asked Questions (FAQs)
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1. How much does a Sewage Treatment Plant cost in India?
For a modern AABR-based stainless steel plant like the SKF Vulcan series, installed cost typically ranges from ₹25 lakh for a 10 KLD unit to ₹1.8–3 crore for a 500 KLD plant, including civil works, piping, and commissioning. Payback through water savings and lower tanker dependency is usually achieved in 4–7 years.
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2. Can treated sewage water really be used for gardening and flushing?
Yes. When treated to CPCB reuse standards (BOD <10 mg/L, TSS <20 mg/L), the water is perfectly safe and widely used for toilet flushing, landscape irrigation, vehicle washing, and cooling tower make-up across thousands of installations.
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3. How often does sludge need to be removed from a modern STP?
In AABR-based plants, excess sludge generation is 30–40 % lower than conventional systems. Most 50–200 KLD plants require de-sludging only once every 18–30 months.
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4. Do STPs produce bad odour that disturbs residents?
Properly designed and maintained AABR plants operate completely odour-free because biological treatment happens in closed stainless steel tanks with adequate aeration and no open settling zones.
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5. Is it possible to install an STP in the basement of an existing building?
Absolutely. The compact footprint (often 40–50 % smaller than civil plants) and modular SS construction of systems like Vulcan STP make basement and terrace installations common in cities like Mumbai, Bengaluru, and Delhi-NCR.
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