Common Effluent Treatment Plant (CETP)

There are some perquisites of the CETP design which form the basis for the entire solution –

• The type of industries that are located in the industrial estate.

• Characteristics of the wastewater, like the flow rate and quality.

• The fluctuations in the kind of discharges that are available in the effluent

• The kind of pretreatment to the wastewater by the various industries, in terms of meeting the CETP standards.

• Checking for the reusability of the treated wastewater and recycling of the wastewater or the safe disposal of the wastewater.

• Knowledge and expertise of the relevant treatment methods along with the availability of energy, manpower, and land for the plant to be set up.

• The industries that are part of the industrial estate need to agree to contribute towards the capital and the expenses for the operation of the CETP that would be set up.

The CETP can be set up as a combined effluent plant so that it can treat all the different types of wastewater from the industries located in the estate, through the use of various methods/steps within the CETP that are available. These include –

• Preliminary Treatment

• Primary Treatment

• Secondary treatment

• Tertiary treatment

• Sludge management

The advantages of the use of the various treatment methods are –

• Diluting the toxic components along with the inorganic solids that have been dissolved in the wastewater.

• Continuous seeding of microorganisms ensures better control over the quality of the wastewater.

• Sewage provides sufficient nutrients

• Operating costs are reduced related to the addition of chemicals.

There are two basic classification types for CETPs –

1. Homogenous – When the various industries in the estate are of similar nature.

2. Heterogeneous – When the various industries produce different products, due to which the quality of the wastewater differs.

Since it becomes difficult to classify the characteristics of the wastewater due to the different industries involved, heterogeneous type of CETP becomes a better option.

• Pretreatment of wastewater is not compulsory.

• Pollution is controlled as the wastewater is treated.

• The governing pollution control authority has only one treatment plant to monitor.

• Partaking industries have the responsibility to generate wastewater as per the CETP acceptance level.

• The responsibility of reduction in pollution and water consumption lies with the partaking industries.

There are various forms of ownership in case of CETP -

1. Private sector ownership

   • The partaking industries form a co-operative company and each industry becomes a shareholder.

   • Advantages of the ownership

     • The partaking industries are committed to pollution control.

     • The partaking industries take care of any problems that may arise concerning the manpower and equipment.

   • Disadvantages of the ownership

     • The partaking industries might have an issue or a conflict may arise when it comes to the quality of the wastewater that needs to be sent to the CETP system.

     • In case, if any partaking industry fails to make a payment, that industry would not be allowed to release their wastewater.

2. Public sector ownership

   • The State Industrial Development Corporation provides the infrastructural capabilities needed for CETP.

   • All industries might not support the compliance and enforcement of the system.

3. Joint Private and Public Sector Ownership

   • The industrial association and the state agency handle the company formation.

   • Though this might improve the funds availability; there might be a delay in execution and the defining of responsibilities. These include –

     • Basic information

     • Collection and conveyance

     • Pretreatment

     • Planning

     • Recycle and reuse of treated effluent or disposal.