Analysis of Hydrogeochemical Characteristics of Tunnel Groundwater Based on Multivariate Statistical Technology

Table 1

Conventional indexes and limits of groundwater quality (mg/L).

Class	pH	TDS	SO4^2-	Cl^-	Fe	Al	NH4^+	Na^+	NO3^-	F^-	As
I	8.5	300	50	50	0.1	0.01	0.02	100	2	1	0.001
II	8.5	500	150	150	0.2	0.05	0.1	150	5	1	0.001
III	8.5	1000	250	250	0.3	0.2	0.5	200	20	1	0.01
IV	9	2000	350	350	2	0.5	1.5	400	30	2	0.05
V	9	2000	350	350	2	0.5	1.5	400	30	2	0.05