The Metropolitan Water District of Southern California
General Mineral and Physical Analysis of Metropolitan's Water Supplies
Table D
August 2025
		SOURCE WATERS								TREATMENT PLANT EFFLUENTS
CONSTITUENTS	UNITS	Lake Havasu	San Jacinto Tunnel	Lake Mathews	Castaic Lake	Silver-Wood Lake	Lake Perris	Diamond Valley Lake	Lake Skinner	Wey-Mouth	Diemer	Jensen	Skinner	Mills
SILICA	mg/L	7.6	8.2	8.3	12.4	10.6	5.7	8.9	9.5	9.3	9.3	12.4	9.8	10.7
CALCIUM	mg/L	72	72	71	31	18	26	26	53	50	51	31	54	18
MAGNESIUM	mg/L	26	25	27	13	10	13	12	20	20	20	13	21	10
SODIUM	mg/L	95	94	98	42	36	52	47	75	84	85	50	85	40
POTASSIUM	mg/L	4.9	4.8	5.2	2.8	2.5	3.4	3.4	4.2	4.1	4.1	2.7	4.2	2.3
ALKALINITY, CARBONATE AS CO3	mg/L	0	0	0	0	0	0	0	0	4	4	4	0	4
ALKALINITY, BICARBONATE AS HCO3	mg/L	160	161	151	111	89	117	109	138	124	122	113	129	78
SULFATE	mg/L	220	215	224	62	25	39	42	150	161	166	70	165	32
CHLORIDE	mg/L	98	98	101	47	45	68	60	82	85	85	51	89	46
NITRATE	mg/L	1.1	1.4	1	1.8	0.5	<0.1	<0.1	0.2	0.9	0.9	1.9	0.3	1.0
FLUORIDE	mg/L	0.3	0.3	0.3	0.2	<0.1	0.1	0.1	0.2	0.7	0.7	0.7	0.7	0.7
TOTAL DISSOLVED SOLIDS (TDS)	mg/L	605	599	611	268	192	266	254	463	481	487	293	494	203
TOTAL HARDNESS AS CaCO3	mg/L	293	288	285	133	88	119	120	218	211	213	133	219	89
TOTAL ALKALINITY AS CaCO3	mg/L	131	132	124	91	73	96	89	113	108	106	99	106	70
FREE CARBON DIOXIDE	mg/L	1.5	1.6	4	4.9	1.3	2.6	1.1	1.2	0.6	0.6	0.5	1.4	0.3
pH	pH	8.25	8.22	7.8	7.58	8.07	7.87	8.22	8.28	8.6	8.58	8.61	8.18	8.64
SPECIFIC CONDUCTANCE	μS/cm	996	991	1010	467	354	498	462	788	811	821	509	824	361
COLOR	CU	--	--	--	--	--	--	--	--	--	--	--	--	--
TURBIDITY	NTU	0.91	0.4	1	0.73	1.5	1	0.55	1.2	0.04	0.03	0.03	0.05	0.05
TEMPERATURE	°C	24	27	24	15	23	24	18	26	24	26	21	30	26
BROMIDE	mg/L	0.08	0.05	0.08	0.14	0.13	0.21	0.18	0.09	--	--	--	--	--
TOTAL ORGANIC CARBON	mg/L	3.78	3.3	3.22	2.86	3.72	4.22	3.32	3.88	--	--	--	--	--
SATURATION INDEX	--	--	--	--	--	--	--	--	--	0.95	0.96	0.7	0.63	0.44
STATE PROJECT WATER	%	0	0	0	100	100	100	100	41	44	40	100	40	100