Sources of Nitrate in Ground Water Aquifers of the Semiarid Region of Tanzania

Table 4

δ¹⁵N and δ¹⁸O isotope signatures for nitrate nutrients in boreholes and shallow wells during the dry and wet seasons.

Boreholes							Shallow Wells
Wet				Dry			Wet				Dry
ID			Rem.			Rem.	ID			Rem.			Rem.
BH 1	23.11	13.66	MN/SE	21.74	12.72	MN/SE	SW 3	16.57	5.90	MN/SE	16.82	7.60	MN/SE
BH 2	33.92	18.58	FT	14.42	20.58	FT	SW 5	24.35	11.47	MN/SE	25.13	16.25	MN/SE
BH 6	22.98	15.83	MN/SE	20.97	11.94	MN/SE	SW 8	33.89	15.94	MN/SE	31.46	15.86	MN/SE
BH 9	22.70	14.30	MN/SE	24.06	14.97	MN/SE	SW 11	31.31	17.70	FT	24.54	11.65	MN/SE
BH 10	13.71	6.41	MN/SE	14.13	8.90	MN/SE	SW 13	21.18	18.79	FT	22.41	11.18	MN/SE
BH 17	16.16	5.59	MN/SE	23.62	16.28	MN/SE	SW 14	14.08	8.13	MN/SE	15.37	10.45	MN/SE
BH 28	10.29	7.83	MN/SE	15.97	7.09	MN/SE	SW 19	18.62	8.04	MN/SE	21.46	12.16	MN/SE
BH 30	25.13	17.29	FT	23.63	17.35	FT	SW 20	18.54	8.08	MN/SE	20.33	11.30	MN/SE
BH 31	24.24	17.60	FT	18.70	16.09	FT	SW 21	18.40	8.25	MN/SE	24.64	14.86	MN/SE
BH 35	15.08	11.67	MN/SE	15.26	12.63	MN/SE	SW 22	20.82	9.99	MN/SE	22.62	13.02	MN/SE
BH 36	16.43	14.52	MN/SE	16.34	12.86	MN/SE	SW 25	24.49	13.42	MN/SE	23.91	13.38	MN/SE
BH 42	15.74	12.50	MN/SE	17.14	15.04	MN/SE	SW 26	24.38	19.84	FT	34.63	19.27	FT
BH 43	13.83	9.58	MN/SE	17.14	13.31	MN/SE	SW 27	20.45	8.25	MN/SE	25.33	16.32	MN/SE
BH 45	14.03	10.43	MN/SE	23.58	16.00	MN/SE	SW 29	23.57	16.71	MN/SE	21.53	13.22	MN/SE
BH 53	29.39	14.63	MN/SE	16.18	11.83	MN/SE	SW 32	20.32	14.64	MN/SE	18.96	13.05	MN/SE
BH 54	27.40	13.91	MN/SE	27.41	15.17	MN/SE	SW 33	27.29	18.35	FT	22.14	15.01	MN/SE
BH 55	22.48	14.36	MN/SE	22.86	13.92	MN/SE	SW 37	31.12	19.52	FT	21.38	16.30	MN/SE
BH 56	23.02	14.45	MN/SE	26.12	15.55	MN/SE	SW 40	24.06	17.76	FT	19.90	15.46	MN/SE
BH 57	22.78	14.36	MN/SE	23.54	16.89	MN/SE	SW 41	20.60	15.48	MN/SE	26.14	14.15	MN/SE
BH 58	23.58	17.00	FT	27.88	17.10	FT	SW 46	25.96	17.55	FT	28.67	18.64	FT
							SW 47	28.57	18.87	FT	25.90	17.15	FT
							SW 49	23.92	15.24	MN/SE	23.25	11.24	MN/SE
							SW 23	16.03	5.16	MN/SE	18.29	9.30	MN/SE

MN/SE; manure/sewage effluents; FT: fertilizers; Rem: remark.