Introduction
With rapid urbanization and the growing number of housing complexes in India, the need for efficient sewage treatment systems has become essential. Every residential society generates a significant amount of domestic wastewater daily — from bathrooms, kitchens, and toilets — that must be properly treated before discharge or reuse. A small sewage treatment plant (STP) for residential society not only helps in environmental protection but also ensures compliance with the Central Pollution Control Board (CPCB) and State Pollution Control Board (SPCB) regulations.
At 3D Aqua Water Treatment Company, we design and manufacture customized STP units from 1 KLD to 500 KLD suitable for residential societies, apartments, villas, and housing complexes. With more than 20 years of experience and a strong presence in over 1050 cities across 9 countries, 3D Aqua is one of India’s most trusted names in sewage and wastewater treatment solutions.
What is a Sewage Treatment Plant (STP) for Residential Societies?
A Sewage Treatment Plant (STP) is a system designed to treat domestic wastewater from residential areas to remove physical, chemical, and biological contaminants. The main goal is to make water clean enough for safe disposal or reuse in gardening, flushing, or landscaping.
A small-scale STP for residential societies generally handles wastewater capacities ranging between 5 KLD to 500 KLD, depending on the number of residents and water usage patterns.
Why Do Residential Societies Need an STP?
Residential societies are significant contributors to urban wastewater generation. Without proper treatment, this wastewater can contaminate groundwater and nearby water bodies, causing environmental hazards.
Here are the main reasons why an STP is essential:
- Regulatory Compliance:
The CPCB mandates that all housing societies with more than 20,000 square meters built-up area or generating more than 10 KLD of wastewater must install an STP. - Water Conservation:
Treated water can be reused for gardening, flushing, and cleaning, reducing dependency on freshwater. - Pollution Control:
Proper sewage treatment prevents the release of harmful pollutants into the environment. - Sustainability:
It promotes sustainable living by recycling wastewater and reducing ecological impact. - Cost Saving:
Reusing treated water reduces water bills and tanker water costs significantly.
Government Rules and Guidelines for STP in Residential Societies
CPCB and SPCB Regulations
In India, the installation and operation of an STP in residential societies are governed by the Central Pollution Control Board (CPCB) and respective State Pollution Control Boards (SPCBs). Below are the key regulatory highlights:
- Mandatory Installation:
As per the MoEFCC (Ministry of Environment, Forest and Climate Change), housing projects with a built-up area above 20,000 sq. meters or generating more than 10 KLD of wastewater must have an on-site Sewage Treatment Plant (STP). - Reuse of Treated Water:
It is mandatory to reuse 50% of treated wastewater for non-potable purposes like toilet flushing, gardening, and car washing. - Effluent Quality Standards (CPCB Norms):
- BOD (Biochemical Oxygen Demand): ≤ 10 mg/L
- COD (Chemical Oxygen Demand): ≤ 50 mg/L
- TSS (Total Suspended Solids): ≤ 10 mg/L
- pH: 6.5 – 8.5
- Fecal Coliform: < 100 MPN/100ml
- Consent to Establish & Operate:
Residential societies must obtain Consent to Establish (CTE) and Consent to Operate (CTO) from their respective SPCB. - Regular Maintenance & Monitoring:
STPs must be maintained regularly, and effluent samples should be analyzed periodically to ensure compliance with CPCB norms.
Design of Small Sewage Treatment Plant Unit for Residential Society
The design of a small STP depends on factors like population, water consumption, peak flow rate, land availability, and local discharge standards.
A typical STP design for residential use includes the following components:
1. Collection & Screening Chamber
All wastewater from bathrooms, kitchens, and toilets flows into a collection chamber.
Here, coarse solids like plastic, hair, and paper are removed through bar screens to prevent clogging of downstream units.
2. Equalization Tank
The equalization tank stores incoming sewage and balances fluctuations in flow and concentration.
This ensures steady and uniform feeding to the biological treatment unit.
3. Primary Sedimentation Tank
This unit allows suspended solids to settle at the bottom while oil and grease float to the top. The settled sludge is removed periodically for further treatment.
4. Biological Treatment Unit
This is the core of the STP, where organic matter is biologically decomposed by microorganisms.
There are several biological treatment technologies used for residential STPs, including:
- MBBR (Moving Bed Biofilm Reactor):
Uses bio-carriers in aeration tanks to provide a large surface area for bacteria to grow. It is compact, efficient, and ideal for small societies. - SBR (Sequential Batch Reactor):
Operates in cycles (fill, react, settle, decant) and provides high-quality treated water. It’s energy-efficient and suitable for moderate load variations. - MBR (Membrane Bioreactor):
Combines biological treatment and membrane filtration, producing ultra-clear treated water suitable for reuse.
Each of these systems is customizable at 3D Aqua, depending on the space, budget, and treatment goals of the residential project.
5. Secondary Clarifier
After biological treatment, the mixed liquor flows to a clarifier where biomass (sludge) settles and clear water moves ahead for further polishing.
6. Tertiary Treatment
To achieve CPCB discharge norms, treated water undergoes tertiary treatment involving:
- Sand Filtration
- Activated Carbon Filtration
- UV Disinfection or Chlorination
This stage ensures pathogen removal and odor control, making water reusable for non-potable applications.
7. Sludge Handling System
The sludge collected from sedimentation and clarifiers is treated in a sludge drying bed or filter press to reduce volume and moisture content before safe disposal.
8. Treated Water Storage and Reuse
The final treated water is stored in a separate tank and reused for:
- Toilet flushing
- Gardening and landscaping
- Floor washing
- Cooling tower makeup (in commercial complexes)
This closed-loop system promotes zero liquid discharge (ZLD) concepts and aligns with Green Building norms.
Compact STP Design Features for Residential Societies
At 3D Aqua, our compact STP designs are space-saving, low-maintenance, and cost-effective. Key features include:
- Modular and pre-fabricated units (1 KLD – 500 KLD)
- Low footprint – ideal for basements or limited spaces
- Energy-efficient blowers and pumps
- Odor-free operation
- Automated PLC-based control panels
- Easy installation and relocation
These systems are designed to meet all CPCB and RERA norms applicable to residential projects in India.
Operation and Maintenance of STP
An STP requires regular monitoring and maintenance to ensure long-term efficiency.
3D Aqua provides Annual Maintenance Contracts (AMC) and after-sales services that include:
- Regular sludge removal
- Equipment inspection
- Blower and pump maintenance
- Periodic water testing
- Operator training
Proper maintenance ensures consistent performance and compliance with regulatory standards.
Cost of Small Sewage Treatment Plant for Residential Society
The cost of an STP for a residential building in India depends on several factors such as capacity, technology used, level of automation, and treated water reuse options.
Here’s a general estimate:
| STP Capacity (KLD) | Estimated Cost (INR) |
|---|---|
| 5 KLD – 10 KLD | ₹2,00,000 – ₹4,00,000 |
| 10 KLD – 50 KLD | ₹4,00,000 – ₹9,00,000 |
| 50 KLD – 100 KLD | ₹9,00,000 – ₹15,00,000 |
| 100 KLD – 200 KLD | ₹15,00,000 – ₹25,00,000 |
| 200 KLD – 500 KLD | ₹25,00,000 – ₹45,00,000 |
Note: Prices vary depending on site conditions, civil work, and customization requirements.
At 3D Aqua, we provide affordable STP solutions customizable to the client’s budget and space availability.
Why Choose 3D Aqua for STP Solutions?
3D Aqua Water Treatment Company is a trusted leader in wastewater management in India.
Here’s why thousands of residential, commercial, and industrial clients prefer 3D Aqua:
- ISO 9001:2015, ISO 14001:2015 & ISO 45001:2018 Certified Company
- 20+ years of experience in water and wastewater projects
- Manufacturing units in Okhla (Delhi) and Sector 10, Noida (UP)
- Serving 1050+ cities in 9 countries
- Expertise in design, installation, AMC, and consultancy
- Fully customizable STPs from 1 KLD to 500 KLD
- Competitive pricing and on-time delivery
- Dedicated after-sales support and technical service team
We also provide integrated water solutions including ETP, RO, UF, ZLD, and WTP systems for industries, hospitals, hotels, and societies.
Conclusion
The installation of a small sewage treatment plant for residential society is not just a government mandate—it’s a necessity for sustainable urban living. By treating and reusing wastewater, societies can conserve water, reduce pollution, and comply with environmental norms.
At 3D Aqua Water Treatment Company, we combine innovation, reliability, and affordability to deliver world-class STP solutions across India. Whether you need a compact 5 KLD unit for a small apartment or a 500 KLD plant for a large township, we provide custom-designed, energy-efficient, and CPCB-compliant systems tailored to your needs.
Contact 3D Aqua Water Treatment Company
📍 Office Locations:
- Okhla Industrial Area, Delhi
- Sector 10, Noida, Uttar Pradesh
📞 Phone: 0120 – 415 3030
📱 Mobile: 70111 43366, 626262 9090
📞 Helpline: +91 89630 89630
✉️ Email: info@3daqua.in
🌐 Website: www.3daqua.in
👥 Clients List: https://3daqua.in/clients
📦 Products: https://3daqua.in/products
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