CPCB Guidelines for Sewage Treatment Plants

According to the legal guidelines gave by CPCB, different infrastructures like Apartments, Commercial Development Projects, Educational Institutions, Municipalities, and Area Advancement Undertakings meeting specific models need to introduce STPs for the treatment of sewage that they produce.

The guideline rules cover angles in regards to the area of STPs, the STP technology to take on, working as well as its maintenance to guarantee effective and safe activity of the machinery.

The Guidelines gave for STPs by CPCB are as per the following: CPCB Guidelines for Sewage Treatment Plants 1. The Technology of STP The approved STP technologies to go with areA. Activated Sludge Process (ASP) (just when over 500 KLD sewage is generated).

B. Membrane Bio Reactor (MBR) C. Moving Bed Bio Reactor (MBBR) 2. Unit Requirements of STP STPs have different individual units where different sewage treatment processes happen. The units and their criteria according to the guideline’s prerequisite are as per the following.

SNo.

Unit

Activated Sludge Process (ASP)

1

Equalization Tank

2

Anoxic Tank

3

Aeration Tank

4

Membrane Tank

Should have a minimum holding period of 8 hours Return activated sludge should be pumped to anoxic tank for denitrification.

Dissolved Oxygen in an excess of 4 mg/L has to be maintained in the Aeration Tank.

Not Required

Sequential Batch Reactor (SBR) Same as ASP

Membrane Bio Reactor (MBR)

Moving Bed Bio Reactor (MBBR)

Same as ASP

Same as ASP

Not Required

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Not Required

Membranes Not Required should be replaced regularly as per its manufacturer’s specifications

5

Sludge Holding Tank

6

Final Treated Water Holding Tank

7

Sludge Drying Bed

Sludge holding should be madatoriliy provided for holding excess sludge before its dewatering.

Capacity of the tank should be enough to hold water for 2 days minimum.

Instead of sludge drying bed, horozontal centrifuge system should be used for >500KLD STPs.

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

Same as ASP

For <500 KLD STPs, belt press or screw press system should be used.

3. Mechanical Equipment Requirement for STP There should to be clear and simple access to the Bar Screen Chamber and Oil and Grease Chamber of STPs introduced. Likewise, the supplies should to be of the submersible sort with a simple removal/it is expected to destroy choice at whatever maintenance is required.

Air blowers of STP should to have Vibration mounts and acoustic fenced in areas to diminish the noise pollution.

4. Location of STP STP should to be situated under the driveway, play area, or clubhouses, and distant from the residential housings to not make any subtlety individuals living.

Additionally, STP should not be installed in that basement of any structure or building.

Admittance to the STP room should to be from Ground Level or Upper Basement through all around designed walkways or headroom, and not from the lowest basement to stay away from subtleties that might occur because of rain flooding, smell or sound.

5. Treated Sewage Standards The sewage treated should meet the following standards.

S NO.

Parameter

Required Standards

pH

6.5-8.5

BOD(5th Day)

<10mg/l

COD

<50mg/l

Suspended Solids

<10mg/l

Ammonical Nitrogen

<5mg/l

Total Nitrogen

<5mg/l

Fecal Coliform

<100MPN/100ml

6. Guidelines for installing sensors It's compulsory to introduce sensors for observing sewage parameters like BOD, COD, TSS, stream, and pH. The CPCB suggested sensor types with their correspondence conventions are as per the following.

S. No.

Parameter

Measurement

Sensor Type

Type 1

pH

Inline

Communication Type

Ion Selective Glass

RS 485

Electrodes

Communication with Modbus

2

TSS

Inline

Turbidity to TSS

RS 485

correlation with

Communication

Nephelometric

with Modbus

technique 3

BOD

Inline

UV-Vis

RS 485

Spectrophotometry

Communication

&

with Modbus

combustion(Double beam with entire spectrum scanning 4

COD

Inline

UV-Vis

RS 485

Spectrophotometry

Communication

&

with Modbus

combustion(Double beam with entire spectrum scanning

5

Flow

Inline

Electromagnetic

RS 485

Flow Measurement

Communication with Modbus

7. Caution Board at STP Legitimate preventative billboards should to be displayed and security conventions should to be followed at the STP locations.

"Danger" Sign Sheets should to be introduced at the STP area for the maintenance personals and general public. What's more "water not well for drinking" should to likewise be featured at the taps conveying sewage water.

8. Use of Treated Sewage The treated water should to be compulsorily utilized for toilet flushing purposes that should to have a double pipes system.

9. Modular Operations of STPs Modern activity of STPs suggests that the STP should to be created/developed in smaller units so it tends to be utilized according to the heap or inhabitance of individuals. In huge tasks where a higher limit of STPs required, the inhabitance in the underlying stages can't meet the functional measures of the STP. Thus, the component should to be viewed as in the plan stage itself.