No of sites in ammonium concentration classes	Ammonium < 0.04 [mg N/l]	Ammonium 0.04-0.1 [mg N/l]	Ammonium 0.1-0.2 [mg N/l]	Ammonium 0.2-0.4 [mg N/l]	Ammonium >= 0.4 mg [mg N/l]	<0.04	>=0.04, <0.1	>=0.1, <0.2	>=0.2, <0.4	>=0.4
Tisa (8)	0	0	8	1	0	0	0	89	11	0
Dnipro (54)	0	0	9	32	13	0	0	17	59	24
Prut (7)	0	0	4	3	0	0	0	57	43	0
Desna (6)	0	0	0	6	0	0	0	0	100	0
Dnister (19)	0	2	5	6	6	0	11	26	32	32
Pivdennii But (20)	4	1	6	1	8	20	5	30	5	40
Sievercki Donets (16)	0	0	0	4	12	0	0	0	25	75
Total (131)	1	12	29	58	31	1	9	22	44	24