Influence of brine discharge on the Puck Bay environment

Transcription

1 Influence of brine discharge on the Puck Bay environment M. Robakiewicz

2 Overview Goal of the study Characteristic of the investment Theoretical approach and technical solution Influence of brine on Puck Bay based on measurements Conclusions

3 Goal of the study Select the optimum location of brine discharge into the sea taking into account restrictions imposed by: - environmental agency - marine administration - ecologists

4 Characteristic of the investment Rewa Zewnętrzna Zatoka Pucka 5 6 zrzut ługowanie rurociąg podwodny Mechalinki rurociąg lądowy OD 7 construction of 10 gas stores in salt deposites at a depth m; total volume 250x106 m3 5.6 x106 t of salt to be dilluted (expected time - 10 years) max. brine parameters: volume m3/h; saturation kg/m3 restrictions: excess salinity not exceeding 0.5 PSU maximum salinity not higher than 9.2 PSU the minimum distance from the installation and water surface 5 m 12th Polish-German Seminar: The Baltic Sea at the middle of 21st

5 5.00 m Theoretical approach and technical solution: analysis of dillution in the near-field C0=5 10 dysze f 8 mm ~1.5 m C» 250 ~ 0.45 m o 2.00 m 3.00 m f 400 mm, stal nierdzewna C» C0+0.7 blok dyfuzora, żelbet m m 45 ~1.5 m ~ 0.5 m ~ 0.5 m ~ 2.00 m f 100 mm lub f 150 mm f 100 mm rurociąg z solanką 2.20 m 3.00 m 7.50 m 6 Widok z góry ~ 0.45 m m m 1.00 m m OD 7.50 m 7 12th Polish-German Seminar: The Baltic Sea at the middle of 21st

6 Theoretical approach and technical solution: analysis of a dillution in near- & far field

7 Spreading of brine in the near-field of installation

8 Spreading of brine in the Puck Bay Simulations: II - III 1997 VI - VII days of still 10 days of uniform wind 2 m/s N, E, S, W 10 days of uniform wind multi-year average N, E, S, W

9 Spreading of brine in the Puck Bay 1997 location location 1 location 4 location 4

10 Applied solution 16 heads with 3 nozzles each heads spaces every 45 m diameter of nozzle - 8 mm exit flow velocity - 35 m/s location 2300 m off-shore (location 1) depth - 8m

11 Execution October 2010

12 Monitoring in the early stage of construction (X 2010 XII 2012) Scope&goal of measurements: - contineous measurements of salinity and currents in the near-field (locations A, B) specify salinity difference between extreme ends of the area in a function of water currents - CTD measurements in the near-field determination of spatial distribution of salinity in the near-field of installation in various conditions - measurements in the vicinity of the single head of diffuser determination of the real mixing conditions of a single jet with the marine environmet

13 Contineous measurements

14 Short-term measurements

15 Measurements in the vicinity of single head f 400 mm, stal nierdzewna blok dyfuzora, żelbet D1-1 f f 2.00 m C= C» 250 dysze f 8 mm ~ 0.45 m ~1.5 m 45 o ~1.5 m C» C m 5.00 m ~ 0.5 m ~ 0.5 m ~ 2.00 m 100 mm lub 150 mm f 100 mm rurociąg z solanką 2.00 m m 1.70 m D m 3.00 m 7.50 m Widok z góry distance [m] A - A ~ 0.45 m 2.00 m 1.00 m 2.20 m 7.50 m distance [m] distance [m] distance [m]

16 Measurements in the vicinity of single head m 5.00 m 2.00 m m 1.70 m dysze φ 8 mm φ 100 mm lub φ 150 mm ~1.5 m 45 o ~1.5 m C 250 ~ 0.45 m φ 400 mm, stal nierdzewna blok dyfuzora, żelbet φ 100 mm rurociąg z solanką ~ 0.5 m ~ 0.5 m ~ 2.00 m C= C C m 3.00 m 7.50 m Widok z góry ~ 0.45 m 2.00 m 2.00 m m 2.20 m 7.50 m

17 Changes of brine parameters ( ) U 0 exit flow vel. d nozzle diameter, ρ a density of ambient water ρ 0 density of effluent

18 Changes of brine parameters ( )

19 Salinity in the bottom layer s

20 Wind velocity changes

21 Salinity changes in the near-field Salinity in the sub-surface layer Salinity in the bottom layer

22 Salinity increase due to brine discharge Salinity measured = natural background + excess salinity due to brine discharge Puck Lagoon ZN6 Cape of Rewa Rybitwia Mielizna Baltic Sea Kuźnica Outer Puck Bay P104

23 Salinity increase estimates based on measurements Salinity measured = natural background + excess salinity due to brine discharge Estimate methods: 1.Salinity difference between sub-surface and botton in S vertical 2.Maximum salinity difference between sub-surface and bottom in the vicinity of installation (verticals S, 9, 10, 17, 18) 3.Maximum salinity difference in the bottom layer in the nearfield of installation (17 verticals) date method 1 method 2 method ,258 0,537 0, ,504 0,604 0, ,422 0,440 0, ,181 0,367 0, ,316 0,362 0, ,414 0,447 0, ,379 0,424 0,486

24 Conclusions Thanks to a system of diffusers mixing of brine in the Puck Bay is good; no permanent salinity increase in the near-field of installation can be observed. Estimated excess salinity due to brine discharge is in the range required by the environment decision. Excess salinity estimated in the pre-investment study (based on laboratory studies) was higher than that observed in natural conditions.

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