3. Identification and Treatment of Emerging Contaminants in Wet Weather
Flows, US Environmental Protection Agency, 2007 - 2013
The presence of emerging contaminants (ECs) in wet weather flows (WWFs) has not been welldocumented, while there has been extensive efforts investing these compounds in wastewater
discharges, water systems, and in natural waters. The initial project activities focused on an extensive
literature review of emerging contaminants in wet weather flows, specifically separate stormwater,
combined sewer overflows (CSOs), and sanitary sewer overflows (SSOs). Characterization (presence and
concentrations) of ECs in wet weather flows and on their treatment is of the most concern for this
project. Although little information exists for separate stormwater, much more exists for sanitary
wastewaters and surface waters. This information allowed us to identify which constituent categories
are likely present in wet weather flows, and in what concentrations. Much information exists for
treatment of ECs in municipal wastewater treatment facilities, and in public water treatment plants.
From this literature information, we are developing a simple screening tool that will consider the likely
presence of the different ECs in the three WWFs of interest, and their treatability by typical and
advanced unit processes applicable to WWFs.
Influent
After primary treatment
Final effluent
After secondary treatment
Tuscaloosa Wastewater Treatment Plant PAHs during rain event #1.
The following are some of the pharmaceutical and personal care products (PPCPs) for which our project
team have developed analytical methods for contaminated surface waters. We are evaluating selected
compounds in our analytical scheme:
Ibuprofen
Diltiazem hydrochloride
Gemfibrozil
5,5-Diphenly hydentoin
Divalproate sodium
0
2
4
6
8
10
12
14
Minutes
16
18
20
22
24
26
28
30
0
Minutes
12
60
30
0
14
2
4
16
6
18
20
40
8
10
20
Pk #
Area
Retention Time
SPD-M20A-263 nm
0510Final010116Acid
12
22
10
0
14
16
24
20
18
20
26
22
24
26
28
mAu
40
21 63438 23.088
15697 23.492
22686 23.960
22
23 14424 24.448
24
25.420
25 1436825.728
7117 26.328
26
26.532
1641
27 4639
27.000
28 1806 27.368
29 2638 27.744
30 4721
31
28.704
32 26622
10723 28.972
29.300
29.592
5268
33 10458
34
35
36
40
19.880
12
11
18.852
8
18.468
705924
19.484
450352
325656
241514
27
47184 26.560
27.024
289712 27.364
29 2434
37928 27.732
28.008
30
8390
31
44133 28.624
32
29253 28.916
104927
29.280
33
34
35
mAu
16.296
19.684
17.408
1005924
6
643625
16.740
317822
13
20.164
14
261643
20.712
137392
16 20.968
319533
17
21.420
18
57416 21.784
215801
19
22.144
20
21 139027
23.084
40733 23.456
22
23.992
23 26383
35350 24.352
24
25
12985 25.416
25.744
26 6754
651031
5
176887
15.536
12.960
194623
140950
2
14.428
1027515
1131617 17.628 7
18.024
15.112
3
142916
60
97608 13.416
1
80
15
20
819074
mAu
SPD-M20A-263 nm
0510Prim010116Acid
1612
14.232
832714.508
3
22366 14.952
4 687
48771 15.552
5
15.764
6
195960
16.308
7
138021
167221 16.772
17.172
9 1 8
209190
10
17.584
11
12
191337
18.508
300781
13
28584518.908
19.192
97425 19.524
15
19.928
16
17
8961
20.724
31880 18
19
181195
20
21.904
Influent
mAu
80
Pk #
Area
Retention Time
2
19.480
16.400
120
9
10
20
16480 12.500
14389 13.068
19796 13.444
13.772
4
38
61154 28.708
54432 28.984
36
29.508
37 26871
35
60
mAu
mAu
26
38 485
39
24
27.096
32 7967 27.432
33 1494
65616 27.820
34
12720 25.468
25.800
30 7483
31
50261 26.652
29
33146 24.468
28
19.984
972654
269809
15
14
1443008
100
18.068
20
22
1
SPD-M20A-263 nm
0510Second010116Acid
20
22 56186 23.076
17187 23.500
23.932
26229
23
24.424
24 11637
24.972
25
13097 25.408
26 1484
25.740
27 7002
26.336
28
26.520
1824 26.700
29 2100
1314 26.968
30 1939 27.348
31
2401 27.728
32
33
7397
34
28.736
35
29664 28.952
8918
29.564
36 15028
29.900
37
18
18.072
Pk #
Area
Retention Time
16452432
20.276
75336 20.576
13602 20.784
18
231731
21.136
19
445163
20
21.532
406030
21
21.860
206046
22
22.248
23
22.736
24
1575
167330
23.160
25
61777 23.520
26
27 70325 24.072
1573178
17.232
9
15.616
18.536
411595
18.916
301419
8
15.260
92586 463964
SPD-M20A-263 nm
0510Influ010116Acid
406059
10
16.280
16
432884
30
14
776738
1366333
17.532
1364187 17.772
10
18.092
20
14
0
267524
12
7
13.108
13.368
3386 157806 13.668
2
3 41064 14.340
4
62425 14.648
80
15
11
40
Pk #
Area
Retention Time
17
11
12
13
60
20339 12.776
139770
100
5
6
1
mAu
120
26432 13.064
55888 13.420
33528 13.748
14.012
14.232
61832 14.480
1
29555
127748
2 323
14.932
3 21619 15.344
45
21819 15.560
35799 15.824
6
7
8
87648 16.772
10
9 106588
17.172
128132
17.592
12
114497
13
18.500
180631
14
15665818.912
19.204
273096
19.536
16185962
19.936
17
18
20.724
4220219
20
123186
21
21.892
mAu
Dichlofenac
Caffeine
Trimethoprim
Triclosan
In addition, estrogen, common veterinary medications, along with some lotions and fragrances are
being added to our list, depending on reported frequency and concentrations from the literature, and
the likelihood of their presence in WWFs. The analyses of characterization samples are being conducted
using HPLC and GC/MSD. Pesticides are being analyzed using GC/ECD, while heavy metals are being
examined using a variety of methods (ICP and ICP/MS).
The analytical scheme includes sampling at a wastewater treatment plants during wet weather. The
treatment plant is a separate sanitary sewage treatment facility, but is affected by typical infiltration and
inflow, or I&I during large flows. Source area samples in different land uses are also being collected.
About 50 source area sheetflow samples are being collected during many different rains. Four locations
at the wastewater treatment facilities are also being sampled during seven rains and seven dry weather
periods. This information, along with specialized laboratory tests, is being used to identify treatability of
the ECs found in wet weather flows.
80
60
40
20
28
Minutes
28
After primary treatment
60
40
20
0
Minutes
30
After secondary treatment
Effluent
HPLC analyses for other organic ECs for first event at the Tuscaloosa treatment plant. Compounds
commonly identified include the acidic pharmaceuticals sulfamethoxole, trimethoprim,
carbamazepine, and fluoxetine.