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WHY A FEASIBILITY STUDY

The steps of a project on wastewater treatment and disposal



STEPS IN A SEWAGE TREATMENT AND DISPOSAL (or REUSE) PROJECT.

A project on sewage treatment and disposal usually requires the following steps:
  1. Pre-Feasibility Study (or preliminary study, 'anteproyecto' in Spanish).
  2. Feasibility study.
  3. General and detailed design.
  4. Preparation of TOR for bid or direct contract.
  5. Bid call and assignment and/or contract.
  6. Construction and inspection.
  7. Start-up.
  8. Normal operation.

The steps may be somewhat different in BOT (build, operate and transfer) projects, but the essential procedure is the same.



THE PRE-FEASIBILITY STUDY.

What is a Pre-feasibility Study ?

The Pre-Feasibility Study includes: If reuse of the treated effluents for irrigation is a potential disposal alternative, the Pre-Feasibility Study will also address the:
Who should perform the Pre-feasibility Study ?

In some cases the organization/institution that requires the study (water company, municipality, etc.) has the technical capacity to perform the Pre - Feasibility Study by itself.

If an external consultant is contracted, it must be an independent consultant, i.e., a consultant who is not a provider of equipment or products for sewage treatment and disposal / reuse.

Providers of equipment and products are more interested in selling their products than in minimizing the investments and O&M (operation and maintenance) costs.


What is the cost of a Pre-feasibility Study ?

The cost of this study depends on the location, size and complexity of the project. A typical Pre - Feasibility Study performed by an international consultant will last about two weeks and will fall in the range of US$ 10,000 - 15,000 including traveling costs (air tickets, etc.).



THE FEASIBILITY STUDY

What is a Feasibility Study for Sewage Treatment and Disposal ?

The Feasibility Study is the key step in the development of a project. The Feasibility Study will determine the data to be used for design, the disposal of the treated effluents, the required quality, the treatment technology, lay-out and size of the treatment units, and cost of the project. The Feasibility Study will prepare the TOR to contract the detailed engineering design.

The Feasibility Study includes: If irrigation with treated wastewater is a feasible alternative, the Feasibility Study will also address:
What is the difference between a Feasibility Study and a Master Plan ?

A Feasibility Study addresses one particular project, while a Master Plan has a regional scope and states how the sewage treatment and disposal problems of a whole region must be solved.

Some professionals refer to Master Plans as Regional Feasibility Studies.


Who should perform the Feasibility Study ?

An independent consulting firm.
That means a consultant firm that is not a provider of equipment or products for sewage treatment and disposal.

Providers of equipment and products are more interested in selling their products than in minimizing the investments and O&M costs of the client.

Providers can not perform an objective comparison between different treatment and disposal alternatives, because they will benefit by recommending the alternative which makes use of the equipment and products they sell.

Recompilation of local data is an important part of the Feasibility Study. Thus, if an international consultant firm is contracted to perform the Feasibility Study, it has to work together with a local engineering firm.


What is the cost of a Feasibility Study ?

The cost depends on several parameters, mainly on: A generally accepted rule is that a Feasibility Study should cost about 1-2 % of the cost of the designed treatment plant. For example: if the Pre-Feasibility Study estimated the cost of the treatment plant in 10 million dollars, the Feasibility Study should cost about US$ 100,000 - 200,000 .

But this rule has severe limitations: