|
|
Disinfected
(with chlorine)
|
Treated at Richard A.
Reynolds Demineralization Plant
|
Treated at Robert A.
Perdue Water Treatment Plant
|
|
|
Inorganic Contaminants
|
MCL
|
PHG (MCLG)
|
Range and Average
|
National City Well #2 (before treatment)
|
National City Well #3 (before treatment)
|
San Diego Formation Wells 1 thru 5 (before
treatment)
|
Lake Skinner Outlet (Aqueduct,
before treatment)
|
Sweetwater Reservoir (before treatment)
|
Sweetwater Authority Drinking Water (after
treatment)
|
Typical Source of Contaminant
|
|
Fluoride (ppm)
|
2
|
1
|
Range
|
0.34 - 0.36
|
0.41 - 0.43
|
0.15 - 0.331
|
0.20 - 0.25
|
0.28 - 0.30
|
0.26 - 0.30
|
Erosion of natural deposits; discharge from
fertilizer and aluminum factories
|
|
Average
|
0.35
|
0.42
|
0.26
|
0.22
|
0.29
|
0.28
|
|
Alluminum (ppm)
|
1
|
n/a
|
Range
|
|
0.06
|
|
|
0.16
|
|
Erosion of natural deposits; residue from some
surface water treatment processes
|
|
Average
|
|
0.06
|
|
|
0.16
|
|
|
Barium (ppm)
|
1
|
(2)
|
Range
|
|
|
0.054 - 0.1151
|
|
|
|
Erosion of natural deposits; discharges of oil
drilling wastes and from metal refineries
|
|
Average
|
|
|
0.072
|
|
|
|
|
Chromium (ppb)
|
50
|
2.5
|
Range
|
|
14
|
6.9 - 131
|
|
|
|
Erosion of natural deposits; discharge from stell
and pulp mills and chrome plating
|
|
Average
|
|
14
|
10.2
|
|
|
|
|
Radionuclides (a)
|
|
Gross Alpha (pCi/L)
|
15
|
(0)
|
Range
|
|
ND - 4.22
|
ND - 12.11
|
ND - 8.531
|
ND - 4.91,2
|
|
Decay of natural and manmade deposits
|
|
Average
|
|
1.9
|
5.6
|
3.99
|
2.5
|
|
|
Gross Beta (pCi/L)
|
50
|
(0)
|
Range
|
|
ND - 13.42
|
ND - 10.91
|
ND - 7.481
|
1.9 - 4.41,2
|
|
Decay of natural and manmade deposits
|
|
Average
|
|
4.9
|
5.3
|
5.24
|
3.4
|
|
|
Uranium (pCi/L)
|
20
|
(0)
|
Range
|
|
|
ND - 6.461
|
ND - 3.181
|
6.71
|
|
Erosion of natural deposits
|
|
Average
|
|
|
3.0
|
2.61
|
6.71
|
|
|
Turbidity (b)
|
|
Combined Filter Effluent Turbidity (NTU)
|
TT
|
no standard
|
Highest single measurement
|
0.45
|
Soil runoff
|
|
Lowest monthly percent of samples meeting MCL
|
100%
|
|
Unregulated Contaminants
|
|
Perchlorate (ppb)
|
Not regulated
|
Range
|
|
|
|
ND - 6
|
|
|
EPA regulations require us to monitor this
contaminant while EPA considers setting a limit on it.
|
|
Average |
|
|
|
ND |
|
|
|
Unregulated Radiological
|
|
Radon (pCi/L)
|
No standard
|
Range
|
|
|
190 - 3001
|
|
|
|
Decay of natural deposits
|
|
Average
|
|
|
232
|
|
|
|
| |
|
Water Distribution Regulatory Compliance
|
|
Organic Chemical Contaminants
|
|
Total Trihalomethanes (TTHMs) (ppb)
|
100
|
Not applicable (c)
|
Highest running annual average
|
|
|
|
|
|
49
|
By-product of drinking water chlorination
|
|
Range of all distribution sample points
|
|
|
|
|
|
1.0 - 109.23
|
|
Lead and Copper Rule |
# of sites found above AL
|
90 percent of samples below
|
|
|
Lead (ppb)
|
AL=15
|
2
|
5 sites above AL out of 50 sites sampled
|
|
|
|
|
|
13.52
|
Corrosion of household plumbing systems
|
|
Copper (ppb)
|
AL=1300
|
170
|
1 site above ALout of 50 sites sampled
|
|
|
|
|
|
5502
|
Corrosion of household plumbing systems
|
|
Microbiological
(d)
|
Highest monthly percentage
|
|
|
Total Coliform Bacteria
|
5.0%
|
(0)
|
# of positive samples taken this year = 0
|
|
|
|
|
|
0
|
Naturally present in the environment
|
|
Fecal Coliform Bacteria
|
(d)
|
(0)
|
# of positive samples taken this year = 0
|
|
|
|
|
|
0
|
Human and animal fecal waste
|
| |
Disinfected
(with chlorine)
|
Treated at Richard A.
Reynolds Demineralization Plant
|
Treated at Robert A.
Perdue Water Treatment Plant
|
|
|
Inorganic
Contaminants
|
Secondary MCL
|
Range and Average
|
National City Well #2 (before treatment)
|
National City Well #3 (before treatment)
|
San Diego Formation Wells 1 thru 5 (before
treatment)
|
Lake Skinner Outlet (Aqueduct,
before treatment)
|
Sweetwater Reservoir (before treatment)
|
Sweetwater Authority Drinking Water
(after treatment)
|
Typical Source of Contaminant
|
|
Iron (ppb)
|
300
|
Range
|
|
130
|
|
|
232
|
|
Leaching from natural deposits; Industrial wastes
|
|
Average
|
|
|
|
|
|
|
|
Manganese (ppb)
|
50
|
Range
|
|
|
62 - 15001
|
|
45
|
|
Leaching from natural deposits
|
|
Average
|
|
|
504
|
|
45
|
|
|
|
Specific Conductance (microseimens/ centimeter)
|
1600
|
Range
|
975 - 1092
|
1117 - 1194
|
1745 - 41371
|
759 - 827
|
861 - 922
|
861 - 951
|
Substances that form ions when in water; Seawater
influence
|
|
Average
|
1032
|
1148
|
2636
|
786
|
894
|
875
|
|
Total Dissolved Solids (ppm)
|
1000
|
Range
|
593 - 618
|
644 - 692
|
1039 - 24751
|
452 - 491
|
539 - 596
|
499 - 596
|
Runoff/leaching from natural deposits; Seawater
influence
|
|
Average
|
605
|
674
|
1534
|
467
|
562
|
546
|
|
Chloride (ppm)
|
500
|
Range
|
208 - 221
|
210 - 220
|
443 - 10781
|
62 - 80
|
127 - 149
|
80 - 166
|
Runoff/leaching from natural deposits; Seawater
influence
|
|
Average
|
215
|
215
|
601
|
72
|
139
|
132
|
|
Sulfate (ppm)
|
500
|
Range
|
47 - 50
|
64 - 66
|
104 - 2741
|
160 - 176
|
91 - 99
|
93 - 170
|
Runoff/leaching from natural deposits; Industrial
wastes
|
|
Average
|
49
|
65
|
180
|
169
|
94
|
121
|
|
Sodium (ppm)
|
NS
|
Range
|
147
|
172
|
281 - 690
|
64 - 73
|
71
|
73
|
Runoff/leaching from natural deposits; Seawater
influence
|
|
Average
|
147
|
172
|
396
|
67
|
71
|
73
|
|
Hardness (Total Hardness) (ppm)
|
NS
|
Range
|
191 - 199
|
204 - 209
|
269 - 656
|
221 - 240
|
252 - 280
|
238 - 272
|
Leaching from natural deposits
|
|
Average
|
194
|
207
|
432
|
230
|
266
|
255
|
