INDUSTRIES / HOTELS AND RESORTS
Sewage treatment plants for hotels
that guests never notice.
A hotel has two water jobs: soft, clean water for rooms, kitchens, laundry and boilers, and a quiet, odour-free STP that turns sewage into water for flushing, gardens and cooling towers. We design, build and run both, starting with a test of your own water and sewage in our NABL-accredited laboratory.
In short
What a hotel needs from its water systems.
A hotel sewage treatment plant (STP) treats wastewater from guest rooms, kitchens and laundry so it can be reused for flushing, landscaping and cooling towers, or discharged within the hotel's consent limits. It usually combines grease traps, an equalisation tank for occupancy peaks, a compact biological stage (MBBR, SBR or MBR) and filtration with UV or chlorine. Softeners and RO on the supply side protect boilers and laundry and give guests good drinking water.
Under the MoEF&CC STP notification of 2017, treated sewage in metro cities must have a BOD of 20 mg/L or less and suspended solids below 50 mg/L; many state boards now ask for the stricter values recommended by the NGT in 2019 (BOD 10 mg/L).
- 2streams
- Fresh water for guests and utilities, sewage back out for treatment and reuse
- 80–90%
- Of the water a hotel uses usually comes back as sewage
- 10mg/L
- BOD in treated sewage recommended by the NGT in 2019, now in many consents
- NABL
- Accredited laboratory that tests your sewage, treated water and drinking water
Where the water goes
Two streams, one property.
A hotel draws borewell, municipal or tanker water that needs filtering, softening and often RO before it reaches rooms, kitchen, laundry, boiler and pool, and sends most of it back as sewage. Both systems must cope with peaks the daily average hides: check-out mornings, breakfast, banquet nights and full weekends.
Where the wastewater comes from
- Guest rooms and toilets: blackwater and greywater (showers, basins); the bulk of the flow.
- Kitchens and banquets: the most troublesome stream, with fats, oil and grease (FOG) that set in drains, clog pumps and coat the STP bacteria.
- Laundry: warm water with detergents, high pH and lint; a large share of water use, so some hotels recycle it separately.
- Pool backwash: chlorinated water with fine solids, in bursts.
- Boiler, cooling tower blowdown and RO reject: small flows, high in dissolved salts (TDS).
How much sewage will your hotel produce?
The National Building Code design figure for hotels is about 180 litres of water per bed per day; full-service hotels with banquets, laundry and gardens use far more. Sewage is usually 80 to 90% of water consumed. As a rough guide, a 100-room hotel with a modest restaurant produces 15 to 20 KLD (kilolitres per day), while a large resort with heavy F&B can reach 60 to 120 KLD. We design from metered water use, not room count.
| Parameter | Typical raw range | Usual treated target | Why it matters |
|---|---|---|---|
| Sewage BOD | 200 to 400 mg/L | 10 to 20 mg/L | Biodegradable load; sets the size of the biological stage and blowers |
| Sewage COD | 400 to 800 mg/L | Below 50 mg/L (NGT value) | Total organic load, including what bacteria break down slowly |
| Sewage TSS | 200 to 400 mg/L | Below 10 to 20 mg/L for reuse | Solids make reused water cloudy and block UV and flush valves |
| Oil and grease (combined sewage) | 20 to 50 mg/L after kitchen traps | Below 10 mg/L | Much higher in raw kitchen water; FOG coats biomass and causes odour |
| Sewage pH | 6.5 to 8.5 | 6.5 to 9.0 | Laundry can push it up; extreme pH upsets the bacteria |
| Raw water hardness (as CaCO₃) | 200 to 600 mg/L in many borewells | Below 60 mg/L after softening | Scale in boilers, calorifiers, laundry machines, showers and kettles |
| Raw water TDS | 500 to 1,500 mg/L | Below 100 mg/L after RO for drinking points | Taste, spotting on glassware, and the guest's impression of the water |
Rules and standards
What standards must a hotel STP meet?
The MoEF&CC notification of October 2017 added STP discharge standards to the Environment (Protection) Rules, 1986. In 2019 the National Green Tribunal accepted stricter values from an expert committee, and many State Pollution Control Boards now write them into consents. Check your own consent.
| Parameter | 2017 notification: metro cities and most state capitals | 2017 notification: other areas | NGT-recommended values (2019) |
|---|---|---|---|
| pH | 6.5 to 9.0 | 6.5 to 9.0 | 5.5 to 9.0 |
| BOD | 20 | 30 | 10 |
| Total suspended solids | Below 50 | Below 100 | 20 |
| COD | Not specified | Not specified | 50 |
| Total nitrogen | Not specified | Not specified | 10 |
| Total phosphorus | Not specified | Not specified | 1.0 |
| Faecal coliform (MPN/100 mL) | Below 1,000 | Below 1,000 | Below 230 (desirable below 100) |
Treatment
How a hotel sewage treatment plant works, step by step.
A compact, low-odour STP sized for occupancy peaks, with a separate pipe network carrying treated water back to flushing and gardens.
| Stage | What happens |
|---|---|
| 1. Grease traps at every kitchen and banquet line | Interceptors slow kitchen water so fat floats and food solids settle. Size them on meals served and empty them on a fixed schedule. |
| 2. Screening and equalisation | A bar screen removes rags and plastics. An aerated equalisation tank absorbs surges (peaks of 1.5 to 2.5 times the average hourly flow) and stays mixed to stop odour. |
| 3. Biological treatment (MBBR, SBR or MBR) | Bacteria eat the dissolved organic matter. In an MBBR (moving bed biofilm reactor) they grow on plastic carriers filling up to about two-thirds of the tank, for a footprint roughly 30 to 40% smaller than conventional activated sludge; design loading is typically 7 to 10 g BOD per m² of carrier surface per day. An SBR treats in timed batches; an MBR uses membranes instead of a settling tank. |
| 4. Clarification | A tube settler or clarifier separates bacteria from treated water. MBR plants skip this step. |
| 5. Tertiary filtration | Sand and activated carbon filters remove fine solids, colour and odour, so reused water looks clean in a guest toilet. |
| 6. Disinfection | UV and a small chlorine residual kill coliform bacteria and stop slime in the flushing lines. |
| 7. Treated water storage and dual plumbing | A separate tank and colour-coded pipe network feed flushing, gardens and cooling towers, never connected to drinking water. |
| 8. Sludge dewatering | Excess sludge is dewatered in a filter press, screw press or drying beds and composted. |
| Process | Best for | Footprint | Treated water | Watch-outs |
|---|---|---|---|---|
| MBBR | Most city hotels, basements, upgrades of old tanks, variable occupancy | Small | Good; meets 2017 limits, NGT values with good tertiary | Carrier screens must stay clear |
| SBR | Resorts with strongly varying flow, properties that need nitrogen removal | Medium | Very good | Depends on a reliable PLC and level sensors |
| MBR | Luxury hotels with little space and high reuse targets, discharge to sensitive areas | Smallest | Excellent, low turbidity, RO-ready | Higher power and membrane cost; keep grease out |
| Extended aeration (ASP) | Large resorts with open land away from guest areas | Large | Good | Open tanks can smell; sludge bulking when occupancy swings |
| Packaged / containerised STP | Small hotels, homestays and remote resorts up to a few tens of KLD | Very small | Good if well operated | Little buffer for banquet peaks; check the access for servicing |
On the supply side: softeners, RO and pool water
Softeners
Ion-exchange softeners take hardness below about 60 mg/L, protecting boilers, laundry machines and dishwashers from scale. See our commercial water softeners.
RO for drinking and kitchen
A dedicated RO plant supplies drinking points, ice and coffee machines and the kitchen, usually below 100 mg/L TDS. RO reject can go to flushing if its TDS allows.
Swimming pools
WHO guidance for public pools is pH 7.2 to 7.8 with free chlorine no higher than 3 mg/L. We supply pool and water treatment chemicals and test pool water for bacteria.
Our NABL-accredited laboratory tests treated sewage for BOD, COD, TSS, nitrogen and faecal coliform, and tests drinking, pool and cooling tower water for bacteria including Legionella. You get reports you can show your board, your brand auditor or a green building assessor.
Reuse
How much water can a hotel recycle?
Treated sewage is a hotel's most reliable water source: it arrives daily, in proportion to occupancy. With dual plumbing it can supply:
- Toilet flushing, often a quarter to a third of guest-room water use.
- Landscaping, the largest use at many resorts.
- Cooling tower make-up, after softening if hardness is high.
- Car washing and hard-surface cleaning.
Example: reusing 30 KLD saves about 11,000 kilolitres a year; at an assumed ₹60 per kilolitre for tanker or municipal water, roughly ₹6.5 lakh a year.
Guest-contact water stays separate
Pools, showers, drinking points and kitchens are fed only from the fresh water loop. The two networks are colour-coded and never cross-connected.
Legionella and cooling tower hygiene
Legionella grows in warm, stagnant water in cooling towers, hot water tanks, shower heads and spas, and spreads in spray. Good practice: store hot water at 60 °C or more, deliver it at 50 °C or more, flush little-used outlets weekly, and run a cooling tower biocide programme. We supply cooling tower biocides and scale inhibitors and test for Legionella and total bacteria in our microbiology laboratory.
Cost
How much does a hotel STP cost?
Cost depends on flow, process, reuse quality and the site. A basement MBR in a city hotel costs more per KLD than an MBBR on open land.
| Sewage flow | Typical property | Indicative MBBR / SBR plant cost* |
|---|---|---|
| 10 to 20 KLD | Boutique hotel, homestay cluster, small resort (often packaged) | ₹5 to 12 lakh |
| 30 to 50 KLD | 100 to 150-room business hotel | ₹12 to 25 lakh |
| 100 KLD | Full-service hotel with banqueting | ₹20 to 45 lakh |
| 250 KLD and above | Large resort or hotel with convention centre | ₹45 lakh to ₹1 crore and upwards |
*Indicative 2026 ranges for equipment, electricals, tertiary filtration, UV and installation, excluding civil tanks, land, taxes and the dual plumbing network. MBR typically adds 30 to 60% to the equipment cost. Running cost for a well-run MBBR plant is usually in the range of ₹8 to 20 per kilolitre, mostly power. We give a firm price after testing your sewage and visiting the site.
What drives capital cost
- Peak flow, not just average flow
- MBBR vs SBR vs MBR
- Basement, rooftop or open-ground siting
- Odour control and acoustic enclosures
- Reuse quality and dual plumbing length
What drives running cost
- Blower power, worse if blowers run flat out at low occupancy
- Grease trap emptying and sludge disposal
- Chlorine, UV lamps, membrane cleaning
- Operator and monthly lab tests
- Softener salt and RO membranes on the supply side
We audit existing hotel STPs, retrofit MBBR media into old tanks, add tertiary treatment for reuse, and take over operation under an annual O&M contract with monthly NABL reports.
Troubleshooting
Common hotel STP problems, and how we fix them.
- 01The problem
Sewage odour near the lobby, pool deck or basement car park.
What we doFind septic zones, keep the equalisation tank aerated, and cover and vent tanks through an odour scrubber or carbon unit.
- 02The problem
Grease blocks pumps and the biology stops working after banquets.
What we doResize grease traps, set an emptying schedule, train kitchen staff and add an oil skimmer in equalisation.
- 03The problem
Blower and pump noise reaching guest rooms.
What we doFit acoustic enclosures and anti-vibration mounts, and variable speed drives so blowers slow at night.
- 04The problem
Treated water is cloudy or yellow, so housekeeping complains about stained toilets.
What we doFix the clarifier and backwash routine, replace spent carbon and check turbidity daily.
- 05The problem
The plant fails after the low season or a long shutdown.
What we doKeep the biology alive with reduced aeration and recirculation, and restart with seeding and lab checks.
What we offer
Water and wastewater services for hotels.
Sewage treatment plants
MBBR, SBR and MBR STPs with tertiary treatment and UV, designed for reuse and low odour.
STP solutions →Softeners and RO
Commercial softeners and filtration for boilers, laundry and kitchens, with automatic regeneration.
Water softeners →Water and sewage testing
NABL-accredited tests for STP outlet, drinking water, pool water and Legionella.
Testing →Treatment chemicals
Boiler, cooling tower, RO and pool chemicals, plus spares for softeners and filters.
Chemicals →O&M contracts
Trained operators, preventive maintenance and monthly compliance reports for your STP.
EPC and O&M →Smart water metering
Flow meters, CGWA telemetry and dashboards that show water use and reuse by area.
Smart water →Buying guide
What to ask before you buy a hotel STP.
Use this list with any supplier, including us.
- Is the design based on metered water use and peak occupancy?
- Which outlet values are guaranteed in writing?
- How is odour controlled, and where do the vents discharge?
- How loud is it at the nearest guest room?
- How is kitchen grease handled, and by whom?
- What does it cost to run per kilolitre at low and high occupancy?
- Where will treated water go? Ask for a reuse plan.
- Who operates it, and who tests it? Ideally a NABL-accredited lab.
Why Rispri
One team for supply water, sewage and reuse.
Our own NABL lab
We test your raw water, sewage and treated water before design and after start-up, so the designer and the tester work together.
Engineering since 1999
1,498+ plants and turnkey projects for industries, hotels, hospitals and cities.
Softeners, RO and chemicals in house
The supply-side equipment, chemicals and spares come from our own catalogue, so one team answers for the whole water system.
Operate and maintain
O&M contracts with trained operators, monthly lab reports and support with your pollution control board.
Questions
Hotel STP and water treatment FAQs.
Is an STP mandatory for a hotel in India?
Most hotels and resorts need an STP as a condition of their SPCB consent, environmental clearance or building approval, especially without a sewer connection. Small guesthouses may be allowed a septic tank and soak pit, depending on the state, so confirm with your board.
What size STP does a 100-room hotel need?
As a rough guide, about 15 to 20 KLD with a modest restaurant, and far more with banquets and an in-house laundry. The right size comes from metered water use, taking sewage as 80 to 90% of it, plus a peak margin.
What are the STP discharge standards for hotels?
The 2017 MoEF&CC notification sets BOD 20 mg/L and TSS below 50 mg/L in metro cities and most state capitals, BOD 30 and TSS below 100 mg/L elsewhere, and faecal coliform below 1,000 MPN/100 mL. Many boards now ask for the NGT-recommended BOD 10, COD 50 and TSS 20 mg/L.
Which is better for a hotel: MBBR, SBR or MBR?
MBBR is the usual choice for city hotels: compact, tolerant of changing occupancy and easy to upgrade. SBR suits very uneven flows; MBR suits little space and high reuse targets.
How much does a hotel sewage treatment plant cost?
As an indication, an MBBR or SBR plant costs about ₹12 to 25 lakh for 30 to 50 KLD and ₹20 to 45 lakh for 100 KLD, for equipment and installation excluding civil work. MBR adds roughly 30 to 60%. We give a firm price after testing your sewage and seeing the site.
Can treated sewage be used for toilet flushing in guest rooms?
Yes, once filtered and disinfected, through a separate colour-coded pipe network. It must be clear and odour-free, which needs good tertiary filtration and a small chlorine residual.
Can treated STP water be used in the swimming pool or for drinking?
No. Treated sewage is for non-contact uses such as flushing, gardens and cooling towers. Pools, showers, kitchens and drinking points must be supplied from fresh water treated through filters, softeners and RO.
How do we stop the STP from smelling near guest areas?
Odour comes from septic zones: unaerated tanks, old sludge and grease. Keep tanks aerated, remove sludge on schedule, keep grease out, and vent covered tanks through a carbon filter away from guests.
Does a hotel need a water softener?
If hardness is above about 120 mg/L as CaCO₃, common with borewell water, a softener pays for itself by protecting boilers, laundry machines and dishwashers from scale and cutting detergent use.
How do hotels control Legionella?
By storing hot water at 60 °C or more, flushing little-used outlets, cleaning shower heads, and running a cooling tower biocide programme with regular testing. We supply biocides and test for Legionella.
Do you operate hotel STPs?
Yes. We run STPs under annual O&M contracts with trained operators, chemicals and monthly NABL-accredited test reports, and take over plants built by others.
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