Problem zrzutu solanki do Zatoki Puckiej
Abstract
Brine discharge to the Puck Bay — a real problem for future investments
A b s t r a c t. Building of gas storage facilities (underground caverns) in the Kosakowo district by salt body leaching is the second investment of that kind in Poland. However, for the first time brine is to be discharged to the marine environment of the Puck Bay—the area protected within the Natura 2000 network. Over the world, technologies producing brine as a byproduct and its discharge to the water bodies are commonly applied. In regard to marine waters, brine concentration is essential, less than its composition. Procedures preceding the construction of caverns in the Kosakowo district lasted from 1998 to 2008 when the investor finally obtained environmental permit. Selection of the Puck Bay for brine discharge resulted from proximity of salt deposits and from economic reasons, i.e. cost-effectiveness of constructing a pipeline for brine produced in 10 caverns. The main problem of such an investment in marine environment was to meet the requirements of regional authority on not more than 0.5 PSU increase in salt concentration in the close area of discharge outlet (measured over the seabed); a basic salinity amounting 7.5 PSU. This condition should minimize the negative influence of 3.6 million ton of brine discharged during ten-years period into the Puck Bay. During ten years of preparatory works no study was conducted to assess the impact of brine discharge on marine environment, particularly on marine organisms. The only calculations and modeling regarded efficiency of brine diffusion in the water column as it was essential to design diffusers (IBW PAN & Deltares Institute in Netherlands). The studies showed that application of selected technical solutions should enable meeting requirements of regional authorities. The results were incorporated in 2007 Report on Environmental Impact Assessment (EIA) which states that impact of brine discharge on biocenosis of the Puck Bay will be negligible (Jenczelewski et al., 2007; Kruk-Dowgiałło et al., 2008), as the discharge should not cause any considerable changes in water salinity in the diffuser vicinity comparing with natural salinity fluctuations of 2 PSU and salinity increase should not exceed 0.5 PSU. The problem with acquiring the environmental permit appeared when effectiveness of diffuser presented in the EIA Report was questioned by a group of “conservative ecologists”. Consequently, the predicted impact of brine discharge on marine environment was denied. The predicted vision of “ecological catastrophe” was not, however, supported by any scientific evidence. Conclusions of the 2007 EIA were confirmed in the supplementary 2008 EIA and proved that the location of the installation and the method of the discharge of brine to the marine environment is optimal and it can be regarded environmentally sound in context of the nature protection of the Puck Bay. It showed that no brine, but the outflow from the Dębogórze sewage treatment plant will be the main factor negatively affecting the environment of the area. The case study of the gas storage caverns in Kosakowo preparation process shows that a number of arguments used in the interim discussion lacked professional background. Nevertheless they hindered the procedures and led to the situation that previously performed calculations and modeling had to be repeated; and ultimately gave identical results. Spending that time and money on studies on the impact of the brine on the marine biocenoces would be, beyond any doubt, much more beneficial to the environment.
A b s t r a c t. Building of gas storage facilities (underground caverns) in the Kosakowo district by salt body leaching is the second investment of that kind in Poland. However, for the first time brine is to be discharged to the marine environment of the Puck Bay—the area protected within the Natura 2000 network. Over the world, technologies producing brine as a byproduct and its discharge to the water bodies are commonly applied. In regard to marine waters, brine concentration is essential, less than its composition. Procedures preceding the construction of caverns in the Kosakowo district lasted from 1998 to 2008 when the investor finally obtained environmental permit. Selection of the Puck Bay for brine discharge resulted from proximity of salt deposits and from economic reasons, i.e. cost-effectiveness of constructing a pipeline for brine produced in 10 caverns. The main problem of such an investment in marine environment was to meet the requirements of regional authority on not more than 0.5 PSU increase in salt concentration in the close area of discharge outlet (measured over the seabed); a basic salinity amounting 7.5 PSU. This condition should minimize the negative influence of 3.6 million ton of brine discharged during ten-years period into the Puck Bay. During ten years of preparatory works no study was conducted to assess the impact of brine discharge on marine environment, particularly on marine organisms. The only calculations and modeling regarded efficiency of brine diffusion in the water column as it was essential to design diffusers (IBW PAN & Deltares Institute in Netherlands). The studies showed that application of selected technical solutions should enable meeting requirements of regional authorities. The results were incorporated in 2007 Report on Environmental Impact Assessment (EIA) which states that impact of brine discharge on biocenosis of the Puck Bay will be negligible (Jenczelewski et al., 2007; Kruk-Dowgiałło et al., 2008), as the discharge should not cause any considerable changes in water salinity in the diffuser vicinity comparing with natural salinity fluctuations of 2 PSU and salinity increase should not exceed 0.5 PSU. The problem with acquiring the environmental permit appeared when effectiveness of diffuser presented in the EIA Report was questioned by a group of “conservative ecologists”. Consequently, the predicted impact of brine discharge on marine environment was denied. The predicted vision of “ecological catastrophe” was not, however, supported by any scientific evidence. Conclusions of the 2007 EIA were confirmed in the supplementary 2008 EIA and proved that the location of the installation and the method of the discharge of brine to the marine environment is optimal and it can be regarded environmentally sound in context of the nature protection of the Puck Bay. It showed that no brine, but the outflow from the Dębogórze sewage treatment plant will be the main factor negatively affecting the environment of the area. The case study of the gas storage caverns in Kosakowo preparation process shows that a number of arguments used in the interim discussion lacked professional background. Nevertheless they hindered the procedures and led to the situation that previously performed calculations and modeling had to be repeated; and ultimately gave identical results. Spending that time and money on studies on the impact of the brine on the marine biocenoces would be, beyond any doubt, much more beneficial to the environment.