Semih Idiz | Aug 15, 2018 | 0
Deep Sea Discharge Regulations on the Med Coast
Recently your writer has received a question/ a request from an experienced power plant engineer from a different country.
He says that he was interested to find some data about the seashore (Mediterranean) located power plants – based on public references.
Specifically, he would like to know what would be the temperature rise in the seawater cooled condensers. Is there any environment protection law in Turkey that limits this value (or the maximum discharge temperature)? What he would like to know, as “neighbors” on the Mediterranean Seashore, if there is any environment protection law in Turkey limiting the temperature of the power plant discharge cooling seawater (or the temperature increase). Such laws are in effect in the USA, Japan, and since Turkey has recently built seashore power plants and this is the reason he would like to try to look for an answer there.
Your writer asked trusted friends to help to answer the question. One of our experienced friends, who worked in Jubail Desalination plant in Saudi Arabia, shared his experience. Saudis have a big desalination plant in Jubail. They pump huge amount of desalinated purified waster to Riyadh city almost 400 km west of Jubail. Desalination plants have also thermal power plants nearby. The Gulf sea water in Jubail, which would be approximately at 34-36 degrees Celsius, is used in water cooling systems of the thermal power plant. The plant operators first pump the outgoing discharge water into an artificial pond/ lagoon to dilute the hot water with ambient sea water to reduce the water temperature. That pond has approximately 2 km diameter in construction. He told that he caught lots of fish each with approximately 2 kg in weight within 2 hours of boat sailing, since hot water was a quite comfortable place for tropical fauna.
Another friend advised me to review the “Water Pollution Control” Direction of Turkish Ministry of Environment, dated 31st December 2004 numbers 25687. On Table 22-23, it is clearly stated that sea water discharge is limited to 35 degrees Celsius. However whatever would be the dilution rate, Sea water can not exceed 35 degrees Celsius, and moreover During June- September period, Deep water sea discharge can not be increased more than 1 C degrees, in all other months it can not be increased more than 2 degrees however if seawater is less than 28 degrees Celsius then seawater deep sea discharge can be increased not more than 3 degrees Celsius.
Still, my foreign colleague is not satisfied, and he stated that he doubt that the Turkish Power Plants on the Mediterranean shore are cooled with only 1 to 3 degree Celsius seawater temperature increase. Under such a strict condition they need huge seawater flows!!! He thinks that the thermal power plants on Turkish Mediterranean coast should have special permits since they cannot meet the conditions of the Direction.
Moreover the hot water at the plant discharge could allow some nice tropical fish to live in such as big size dangerous sharks, etc. Still, we doubt that the Turkish Power Plants on the Mediterranean shore are cooled with only 1 to 3 degree Celsius seawater temperature increase. Under such a strict condition they need huge seawater flows!!!
We should not get provoked immediately. We need to review situation in cold thinking.
We really wonder if the imported coal firing Adana Ceyhan SUGOZU 2x 660 MWe Thermal Power plant in Yumurtalık meets that environmental condition. It is our feeling that the thermal power plants as well as nuclear power plants on Aegean, Marmara, Black Sea coasts can meet and satisfy that discharge temperature limitations since the overall seawater temperature is quite low there.
We feel that imported coal firing thermal power plants are not suitable for our country, since they have “energy supply risk” as well as they bring ask/ sulphur/ CO2 emissions/ dirt and huge pollution to our sea ports. They also block the development of our local indigenous lignite. We really wonder if our authorities make regular / periodical sea water discharge controls on Adana Ceyhan SUGOZU. That is almost 7 years after groundbreaking at site. Plant is in smooth operation, getting imported coal from Columbia, South Africa, Australia and generating electricity for the country and earning money for the investors.
However when it was the time they applied for “Environmental Impact Report”, the design parameter was based on limitation of sea water temperature not more than 35 degrees Celsius. However that is not possible with the existing average sea water around the thermal power plant. So decision makers advised that the existing direction would be modified in time to be in parallel with the design parameters. Therefore the existing power plant water Deep sea discharge should exceed the limitations.
Life on seashore in on a delicate knife edge natural balance. If you increase the seawater by 2 degrees at almost a random time frame, the creatures, flora and fauna cannot fit their lives into new conditions. They do not live with Ministerial directions. They have their own natural directions. They do not live in hot springs.
So only the fittest creatures will continue to survive, they are single cell planktons. All other fish species are endangered. New bigger and dangerous creatures are invited, such as sharks and others. The return to the early stage would take centuries.
There is no deep sea water injection that is purely direct water injection to the ambient sea water. We normally retrieve cool water from deep sea and discharge the outgoing plant cooling water into sea surface.
In Saudi Arabia 11 x 400 MW Shoaiba Thermal power plant, cooling water is taken from -25m of Red Sea at about 22 to 25 degrees Celsius, and with 7degree Celsius maximum temperature increase it is discharged at 29- 32 degree Celsius which is almost the same temperature at sea surface. Each unit consumes approximately 57,500 m3/hour, total 632,500 m3/hour sea water is pumped in cooling process.
That is said to be minimum effect to the sea life. That much sea water in chlorine then all planktons inside are eliminated, and treated with “residual chlorine” and delivered back to the sea water. Any statement saying “No impact on deep sea water life” is absolutely meaningless.
For Turkish Sugozü 2x 660 MWe thermal power plant, our nearby seawater temperature is 28 degrees Celsius. The water cooling circulation per units is estimated to be 55,000-60,000 m3/hour, so the temperature increase should be around 10- 11 degrees Celsius in single pass cooling. That yields a discharge water temperature of 37 degrees Celsius.
We need to check where we make the discharge, at what distance and at what dept of the sea. We talk about Mediterranean Sea, not a river basin. Any temperature difference as low as 1-2 degrees Celsius will make some creatures in more advantageous and some creatures at less advantageous situation.
We are not in position/ nor have any right to change the natural laws of the world, otherwise we pay back dearly.
Your comments are always welcome.