Table 1 Chemical and isotopic composition of the groundwaters. Concentrations of chemical elements and ions are given in mg L⁻¹ except for Cs which is in μg L⁻¹. The ¹⁸O/¹⁶O ratio (δ¹⁸O) is reported via the δ notation “per mil” as a deviation from the Standard Mean Ocean Water (SMOW)

pH

7.5

7.4–7.5

7.8

7.2–7.8

Na

1465

1430–1530

3085

3040–3130

Mg

138

121–148

32

31–32

K

40

32–42

14

13–16

Ca

189

186–269

3870

3760–3980

Cl⁻

2780

2683–3050

13400

10810–14600

SO₄ ²⁻

280

280–337

673

637–703

DOC

6.4

6.4–6.4

bd^c

bd–bd

HCO₃ ⁻

212

202–220

6.5

5.5–6.8

δ¹⁸O

−7.5

−7.8 to −7.4

−12.4

−12.4 to −12.4

Fe-total

1.7

1.5–1.7

0.037

0.011–0.063

Fe²⁺

1.6

1.2–1.7

0.06

db–0.06

Mn

0.71

0.70–0.97

0.23

0.23–0.23

HS⁻

0.05

0.01–0.08

0.01

bd–0.07

NH₄ ⁺_N

2.4

2.3–3.1

0.01

0.01–0.02

PO₄ ³⁻_P

0.0071

0.0006–0.0136

bd

bd–bd

NO₃ ⁻

bd

bd–bd

bd

bd–bd

NO₂ ⁻

0.00055

0.0005–0.0006

bd

bd–bd

Cs

4.6

4.5–4.8

4.2

4.2–4.2