Operation of CETP being a participatory mechanism, the  primary  requirement  is hence to define the ultimate responsibility for the proper functioning of the plant after it is commissioned. The important issues which merit consideration are :

Aspect of Ownership

Various  ownership alternatives  include-  the  plant  owned  by  government,  consortium  of  industries or by  an  independent body. Whatever  be  the case, the primary emphasis should be on responsiveness in terms of effective and optimal operation of the  plant  and  accountability. The  member  industries  should  also  be made to realise that they are equally responsible for the sustenance of the plant.

Conveyance System  

Different  from  the discharge  characteristics  of  an   integrated ( big)  industrial  unit, small scale  units usually generate higher proportion  of  floating  or  suspended  particles  in  their  effluent  streams.  At  times their job operation result in high corrosive effluent.  In  either  of  these  cases , to  effectively  convey  their effluent to the CETP , it becomes necessary for individual units to set-up a ‘pre - treatment’ device. It is also necessary that the conveyance network be so designed as to ensure their periodic de-sludging. Care should also be taken to minimise on cost of operation by facilitating conveyance through gravity flow, instead of multistage pumping. In fact the location of CETP should be selected after a careful topographical survey of the drainage area to keep the conveyance route as   short as possible. The chances of flooding in monsoon and accidental surface run-off into the conveyance route should  also  be  looked into. Conveyance by tankers is another option, provided the chances of leakage are effectively checked and their transit is strictly monitored in accordance to a properly laid down system.

Cost of Treatment

The cost effective treatment supported with a system of regular collection / payment of treatment charges by each member unit, while maintaining  its  effluent quality  within acceptable  norms are some of the prerequisites. The system of payment should be legally supported to provide a check for non-payment of dues and to take steps against defaulters.

Criteria for Cost

The cost sharing should be decided in such a way that volume of effluent becomes an important norm, but its share  in the total cost should not be such as to encourage by-passing of dilute streams and conveying highly toxic / non-biodegradable  waste to CETP. The treatability factor  should also be given due  consideration in cost estimation. An effort by the  industry to segregate toxic, highly  acidic / highly  basic, or  toxic metal bearing waste be made to explore the possibility to de-toxify / neutralize or to attempt  the  recovery  of  metals by  installing  recovery  plants,  which are feasible and economically viable on account of their pay-back potentials.

Plant Design

The approach to provide treatment  at low cost,  an  important factor in common treatment, depends on appropriate design of CETP. In keeping with the diverse nature and scale of  operations, typical of small scale units, low capital investment and lower operation and maintenance cost incurred on treatment is  a prime factor. In such a situation mechanical and chemical processes are advantageous over bio-logical systems. And the least  preferred are conventional anaerobic  processes on account of huge space requirements and least flexibility. Though,, the advanced   UASB  technique  with  less   hydraulic  retention  and  space requirement being significantly low, anaerobic system is also a possible option. In order to obviate the need of  excessive civil work at CETP in making huge equalization and settling units, the member units should also provide settling and neutralization of their individual waste.

In order to minimize on the electrical cost, the possibility of substituting bio-energy should be explored to the extent possible. Proper management of sludge with its nutritive value would mobilize resources to substitute the operational cost.

While designing the plant it would be of additional advantage to keep manpower requirement as low as possible but high in technical skills to reduce down-time for maintenance.

• Advantages of Common Treatment
  • Saving in Capital and operating cost of treatment plant. Combined treatment is always cheaper than small scattered treatment units.
  • Availability of land which is difficult to be ensured by all individual units in the event they go for individual treatment plants. This is particularly important in case of existing old industries which simply do not have any space.
  • Contribution of nutrient and diluting potential, making the complex industrial waste more amenable to degradation.
  • The neutralization and equalisation of heterogeneous waste makes its treatment techno-economically viable.
  • Professional and trained staff can be made available for operation of CETP which is not possible in case of individual plants.
  • Disposal of treated wastewater & sludge becomes more organised.
  • Reduced burden of various regulatory authorities in ensuring pollution control requirement.