2011 Report Summary Tables

St. Johns River Water Management District

St. Johns River Water Management District - floridaswater.com

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Surface Water Quality Index

2011 Water quality status and trends report summary tables

Note: See report page for definitions.

Median analyte values by major basin

Analyte	Indian River Lagoon	Lake George	Lower St. Johns River	Middle St. Johns River	Nassau River	Northern Coastal	Ocklawaha River	St. Marys River	Upper St. Johns River
Ca Mg hardness (calculated mg/L as CaCO₃)	3060.09	208.77	272.30	148.76	1094.21	2683.73	126.39	61.01	137.70
color (platinum-cobalt units)	25.97	64.04	82.51	95.29	251.84	29.18	49.27	387.50	176.15
corrected chlorophyll-a (ug/L)	7.06	13.60	6.85	18.25	5.80	4.71	42.55	0.65	11.54
dissolved oxygen analysis by probe (mg/L)	6.33	6.61	7.08	7.09	5.94	5.66	7.18	6.52	4.93
lab turbidity (NTU)	4.28	3.77	3.69	5.32	9.29	7.27	10.11	2.84	4.83
pH (standard units)	7.91	7.57	7.36	7.62	6.82	7.62	7.91	6.35	7.15
salinity (ppt)	21.67	0.61	2.86	0.29	5.98	24.76	0.17	0.25	0.56
secchi disc transparency (meters)	1.02	0.98	1.09	0.54	0.50	0.94	0.66	0.62	0.50
specific conductance field (uhmhos/cm at 25° C)	33702.69	1227.32	3901.20	751.81	10151.75	38116.10	323.85	946.60	628.38
total alkalinity (mg/L as CaCO₃)	172.72	73.99	44.58	57.03	42.72	113.71	95.34	10.77	67.97
total calcium (mg/L as Ca)	245.25	50.16	46.78	38.59	75.35	185.46	33.89	7.14	40.10
total chloride (mg/L)	9777.13	279.60	479.36	147.22	3349.16	8198.06	27.45	137.00	94.65
total dissolved solids (mg/L dried at 180° C)	17712.00	648.93	1049.36	489.01	5732.25	14397.05	169.56	390.93	343.52
total kjeldahl nitrogen (ug/L as N)	874.52	971.91	797.12	1325.53	1213.13	633.66	2182.66	988.55	1711.05
total magnesium (mg/L as Mg)	595.12	20.11	37.85	12.78	220.04	544.99	10.05	10.44	9.16
total nitrogen (ug/L as N)	931.30	1081.26	855.36	1476.10	1256.78	661.20	2309.74	1013.76	1765.84
total organic carbon (mg/L as C)	11.19	12.81	16.24	18.40	23.27	14.37	22.10	42.86	30.45
total phosphorus (ug/L as P)	75.25	64.11	95.00	93.35	119.80	100.28	73.19	38.99	107.85
total potassium (mg/L as K)	222.82	5.85	12.44	4.28	67.61	203.32	6.13	3.28	3.49
total sodium (mg/L as Na)	5140.93	142.78	245.60	73.58	1788.15	4615.39	13.89	75.67	44.47
total sulfate (mg/L as SO₄)	1363.76	69.81	116.81	59.70	451.80	1178.77	19.58	19.41	27.05
total suspended solids (mg/L)	10.62	6.34	5.41	9.70	22.93	21.90	18.92	4.16	7.44
water temperature (degrees C)	25.06	23.01	21.54	22.26	22.00	23.13	23.25	19.27	24.01

Trend results by analyte
(expressed as the percent of sites)

Analyte	Increasing	Decreasing	Stable	Insufficient Data	No Data
Ca Mg hardness	21.03	5.56	27.78	16.67	28.97
color	3.17	40.08	29.37	24.21	3.17
corrected chlorophyll-a	26.19	12.70	33.33	19.84	7.94
dissolved oxygen analysis by probe	18.25	15.48	54.37	11.51	0.40
lab turbidity	37.30	10.71	32.14	17.06	2.78
pH	55.56	9.92	22.62	11.90	0.00
salinity	43.65	1.19	12.30	13.89	28.97
secchi disc transparency	13.49	21.03	28.17	27.38	9.92
specific conductance field	62.70	5.56	19.84	11.90	0.00
total alkalinity	24.21	8.73	23.02	32.14	11.90
total calcium	21.43	6.35	26.59	16.67	28.97
total chloride	29.76	4.37	22.62	14.68	28.57
total dissolved solids	20.24	4.76	29.76	15.08	30.16
total kjeldahl nitrogen	11.90	39.29	30.16	15.87	2.78
total magnesium	23.02	3.97	27.38	16.67	28.97
total nitrogen	12.30	38.89	30.16	16.27	2.38
total organic carbon	19.05	12.30	44.05	18.25	6.35
total phosphorus	23.41	17.86	40.08	15.87	2.78
total potassium	26.59	3.17	20.63	20.24	29.37
total sodium	25.40	1.98	22.22	21.43	28.97
total sulfate	20.24	5.95	28.17	17.06	28.57
total suspended solids	9.92	34.52	36.90	15.87	2.78
water temperature	3.57	4.76	79.76	11.90	0.00

Note: The trend analysis demonstrates change during the report time period. This report does not attempt to analyze the cause of any change, nor the impact of any change.

Updated on 2-21-2013