TCO water projects
Alternate water sources
One of the first outcomes of the risk assessment was that the reliability of the water source required improvement. Besides improving the reliability of the current source, a prefeasibility study of using alternative water sources was conducted. Various sources of surface water and groundwater were considered, as were connections and expansions to existing treatment facilities. An economic assessment of the most promising options was made based on the advantages, disadvantages and opportunities offered. The assessment took into account future developments, such as reduced water requirements and influence on other water users outside Tengiz. The most promising option was revealed to be the utilisation of local water sources, accomplished by constructing a desalination plant in Tengiz and using water from the Caspian Sea or saline groundwater. A third source of water could be brackish groundwater from outside Tengiz, provided by a third party. Initial calculations showed that the cost of water could be reduced in comparison to the current price.
A second result of the risk assessment was the decision to take a closer look at present water usage in Tengiz and study the possible ways in which to optimise water conservation. In order to gain a more comprehensive understanding of present water usage processes, a water balance was set up for Tengiz, showing all average water flows from the intake level to the waste water or effluent discharge points.
This water balance showed that some camps use much more water per capita per day than others. These considerable differences are likely to be a result of leakage, metering and the level of consumer awareness of water usage in some of the villages. If water usage were to be reduced to a level similar to the camp with the lowest water usage, a huge saving on water consumption could be achieved. These projected savings are so substantial that they would return on their required investment after only a couple of years.
The most important water saving project is to use recycled effluent from one of the wastewater treatment plants. A water recycling facility is under design that will recycle effluent to technical water, to make it suitable for use in industrial acitvities. Although technically possible, effluent will not be recycled to be used as drinking water.
The total amount of water which could feasibly be saved in the camps and industrial areas by means of the abovementioned measures is estimated to be approximately 50 %. By treating the water from the new source until it reaches a level of quality equal to that of the present drinking water treatment plants, a centralised treatment plant in Tengiz could render the present four treatment plants obsolete. This would reduce costs with regard to operation and maintenance.
The main water consumption processes identified in the industrial areas have been studied in more detail. Effluent from several of these processes can be reused, for example as make-up water, thereby reducing the total effluent flow. Once the capacity of the existing industrial treatment plants is exceeded, these measures will improve treatment capacity and reduce effluent discharge volumes.
The defined measures will be developed further in the following phases of the project. The results of each phase, including more detailed cost estimates, will ensure the right decision is made regarding if and how to continue with each defined project.