The first phase of any commissioning process, after handover from construction, is to prove the pressure envelope of that system, for gaseous systems this typically is with air and for aqueous systems, water. After proving leak tightness’, commissioning usually proceed with water and air commissioning and trying to prove the design intent.
Some plants do have outfall limitations, even for a large scale chemical complex, in that the environmental discharge limitations on volume and specification are extremely tight. Many plants are designed to not create aqueous waste at all, this design factor may be challenged during initial commissioning when water treatment systems are not available, (chemical introduction comes after the water commissioning phase).
Therefore consider the development of a waste water management plan. Typically these are based on the logical commissioning of the asset, discharging water from one tank to another, in such a manner as to minimise waste water created. However the handover of systems from construction to commissioning can on many occasions, not actually occur in the ideal sequence required and the commissioning team can have significant challenges in reducing water wastes. So please consider by exploring additional options, e.g. use of foul drains, tankering water off site (costly and not sufficient money in the commissioning budget?) and significant extra “out of the box” thinking to pump water via different inter-tank routes within the process. Filtration of waste water can was also be considered.
It could be to your advantage during the commissioning preparation phase, to consider a desk top exercise to consider how to manage the extra water commissioning may potentially produce. Run “none ideal” tank availability scenario’s and its processing consequences, make procedural action plans and obtain quotes and lead times for filtration and polishing systems to reuse the optimum amount of water possible. Also consider the additional materials, tanks, pumps and hoses that would potentially be required and include these costs in your budget.
It is also worth considering if steam is being used in the process, how condensate is managed as considerable amounts of dirty and waste condensate are produced until the condensate is of a quality that can be used, say as boiler feed water.
Safe and successful commissioning always….