SEWAGE TREATMENT PLANT DESIGN

Sewage Treatment Plant (STP) Design as per CMDA Norms

Introduction

A Sewage Treatment Plant (STP) is a crucial infrastructure component for residential, commercial, and industrial projects, ensuring proper wastewater management. In Chennai, the Chennai Metropolitan Development Authority (CMDA) has set specific norms for STP design and implementation to promote sustainable and environment-friendly sewage disposal.

Why is STP Compliance with CMDA Norms Important?

• Ensures legal approval for building projects.
• Prevents groundwater contamination and promotes environmental sustainability.
• Facilitates efficient wastewater treatment before discharge.
• Essential for obtaining a Completion Certificate (CC) and Occupancy Certificate (OC) for buildings.

CMDA Norms for STP Design

The CMDA (Chennai Metropolitan Development Authority) mandates STP installation in all large-scale residential, commercial, and industrial projects. The key regulations include:

1. Capacity & Sizing Requirements

• STP capacity should be designed based on 80-135 liters per capita per day (LPCD) for residential buildings.
• For commercial buildings, hospitals, and industries, the wastewater load varies based on occupancy and operations.
• The plant must handle peak flow conditions effectively.

2. Treatment Process & Standards

The STP should follow a multi-stage treatment process as per CMDA and Tamil Nadu Pollution Control Board (TNPCB) standards, which includes:

• Primary Treatment: Screening, grit removal, and sedimentation.
• Secondary Treatment: Biological treatment (Activated Sludge Process, MBBR, or SBR).
• Tertiary Treatment: Filtration, disinfection (chlorination/UV treatment), and sludge handling.

3. Treated Water Quality

As per CMDA and TNPCB norms, treated sewage water must meet the following parameters:

• Biochemical Oxygen Demand (BOD): ≤ 10 mg/L
• Chemical Oxygen Demand (COD): ≤ 50 mg/L
• Total Suspended Solids (TSS): ≤ 10 mg/L
• pH: 6.5 – 8.5
• Fecal Coliform: <1000 MPN/100ml

4. STP Location & Construction Guidelines

• Should be located at a safe distance from water bodies and residential areas.
• Must have provision for future expansion.
• Designed with ventilation, odor control, and sludge management systems.

5. Reuse & Discharge Regulations

• Treated water must be reused for landscaping, toilet flushing, or cooling towers.
• Discharge into public drains or water bodies is allowed only after meeting prescribed norms.

STP Approval Process with CMDA

1. Prepare & Submit Design Plans to CMDA along with the building approval application.
2. Review & Inspection by CMDA and TNPCB officials.
3. Approval & Implementation after compliance verification.
4. Regular Monitoring & Maintenance is mandatory post-installation.

Why Choose Us for STP Design?

• Expertise in CMDA-compliant STP design.
• Advanced energy-efficient treatment technologies.
• End-to-end services from design to approval assistance.
• Compliance with TNPCB environmental standards.

Get in Touch

For STP design, approval assistance, and implementation, contact us today!