Gurpal S. Toor

1. Developing Tools to Attenuate Emerging
Contaminants in Onsite Wastewater
Treatment Systems
Gurpal Toor and Chris Wilson
2015 USDA-NIFA NIWQP and AFRI Annual Project Directors’ Meeting, Greensboro, NC
Yun-Ya Yang
Post-doctoral
Researcher

2.  Used to treat and dispose relatively small
amounts of wastewater-usually from
houses and businesses (mostly in rural
areas).
 Evolution: French prototype (only septic
tank). Introduced in 1883 in US. Drainfield
was added in 1930-40s.
 Today’s conventional septic system:
Septic tank and drainfield or leachfield or
soil treatment unit
Background: Septic Systems!
 Florida:
 ~2.5 million septic systems.
Used by 33% households or
~6 million people
 Annual discharge: 156 billion
gallons [40% located in
coastal areas]
 Population using septic systems to
dispose household wastewater:
 US: 25% of households
 Europe: 26% of households
 Australia: 20% of households

3. Objectives
Research: Investigate the occurrence, fate, and transport of
selected emerging contaminants (EC) from septic systems to
shallow groundwater.
Extension: Provide training, education, and outreach on the
risk and ways to reduce groundwater contamination by EC.
3

4. Research Objective # 1:
Fate of EC in Septic Drainfields
4
Center of a DrainfieldEC
TransportEffluent
Septic tank
• Investigate occurrence of EC in effluent and drainfields.
• Determine the mass balance of selected EC in drainfields.

5. 5
Methods: Construction of Drainfields
Drip line
9 L/day of effluent (3L/ft2)
6 doses at 4 h intervals
Leachate
Effluent tank

6. Analysis
• Samples were analyzed by solid-phase extraction and LC-MS/MS
• Targeted 17 selected EC:
6
Markers/
Tracers
(2 )
Pharmaceuticals
(4)
Hormones
(3)
PCPs
(7)
Plasticizer
(1)
Sucralose
(sweetener)
Acetaminophen
(analgesic)
Estrone
(reproductive
hormone)
Triclosan
(anti-microbial
agent)
Bisphenol-A
(plasticizer)
Caffeine
(stimulate)
Carbamazepine
(anti-convulsant)
Estradiol
(reproductive
hormone)
Triclocarban
(antimicrobial agent)
Ibuprofen
(anti-inflammatory)
Sulfamethoxazole
(antibiotic)
Ethinyl Estradiol
(ovulation
inhibitor)
PARABENS
Butyl-
Ethyl-
Heptyl-
Methyl-
Propyl-
(preservatives)

7. 7
Detection Frequency (Jan-Aug)
• 14 EC were detected in the effluent
• Most frequently detected compounds were:
• Markers: sucralose and caffeine (100%)
• Pharmaceuticals: acetaminophen and ibuprofen (>90%)
• Hormones: estrone (88%)
• PCPs: triclosan, triclocarban, ethyl-, methyl-, and propyl paraben (>90%)
• Bisphenol-A: 88%
0 20 40 60 80 100
Sucralose
Caffeine
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
17β-Estradiol
Triclosan
Triclocarban
Butyl Paraben
Ethyl Paraben
Heptyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Septic tank effluent
Sucralose
Caffeine
Acetaminophen
Ibuprofen
Triclosan
Triclocarben
Ethyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol‐A
N = 34

8. 8
Detection Frequency (Jan-Aug)
• 12 EC were detected in leachate
• The most frequency detected compounds:
• Markers: sucralose (83%)
• Pharmaceuticals: ibuprofen (65%)
• Hormones: <20%
• PCPs: triclocarban (68%)
• Bisphenol-A: 48%
0 20 40 60 80 100
Sucralose
Caffeine
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
17β-Estradiol
Triclosan
Triclocarban
Butyl Paraben
Ethyl Paraben
Heptyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Leachate
Sucralose
Triclocarben
Bisphenol‐A
Ibuprofen
N = 120

9. 0
100
200
300
400
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Rainfall(L)
0
20
40
60
80
100
120
140
160
180
200
0
10000
20000
30000
40000
50000
60000
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Clconcentration(mg/L)
Concentration(ng/L)
Sucralose
Caffeine
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
Triclosan
Triclocarban
Butyl Paraben
Ethyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Cl
Septic tank effluent
25-54,000 ng/L
N = 34
9
Temporal Variability (Individual) in Effluent

10. 10
Temporal Variability of Tracers in Leachate
0
200
400
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Rainfall(L)
0
20
40
60
80
100
120
140
160
180
200
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Clconcentration(mg/L)
Concentration(ng/L)
Sucralose
Cl
Leachate
290-8,900 ng/L
N = 120

11. Temporal Variability (Individual) in Leachate
0
200
400
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Rainfall(L)
N = 120
0
20
40
60
80
100
120
140
160
180
200
0
20
40
60
80
100
120
140
Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13
Clconcentration(mg/L)
Concentration(ng/L)
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
Estradiol
Triclocarban
Heptyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Cl
Leachate
6-130 ng/L
11

12. 12
Summary: Mean Concentrations in Effluent & Leachate
• EC are present in effluent and septic drainfields
• Conc. decreased as effluent percolated in vadose zone
N = 34 N = 120
Septic tank effluent Leachate
Conc. were <50 ng/L

13. 13
Mass Balance of EC in Drainfields
• <14% of applied EC in STE recovered in leachate
• >84% either remained (stored) in soil, degraded in unsaturated soil zone
• <2% plant uptake (based on literature)
0 20 40 60 80 100
Sucralose
Caffeine
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
Estradiol
Triclosan
Triclocarban
Butyl Paraben
Ethyl Paraben
Heptyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Leachate
STE
%
Sucralose
Caffeine
Acetaminophen
Carbamazepine
Ibuprofen
Sulfamethoxazole
Estrone
Estradiol
Triclosan
Triclocarban
Butyl Paraben
Ethyl Paraben
Heptyl Paraben
Methyl Paraben
Propyl Paraben
Bisphenol-A
Leachate
Soil storage

14. 14
Methods: Sorption and Biodegradation of EC
Sand
Soil
Soil collected from drainfields
Incubation
Study
60 d incubation study
• 5 g sterilized (autoclaved) or
unsterilized soil/sand
• Spiked 25 ng/g of EC
• ~10% of moisture content
• Anaerobic: N2 for 5 min
• Aerobic: kept aerated
• 3 replicates for each treatment
• at 22°C in the dark
EC
Extraction
• What are the mechanisms of EC
attenuation in the drainfields?
• Do microorganisms in the
drainfields break down EC?
?

15. Sorption and Biodegradation?
Carbamazepine
cm
cm
Drip line
Sand
Sand
Soil
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Sand
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Soil
Sorption (sterile)
Aerobic
Anaerobic
• 77- 594 pg/g on the top and side 15
Leaching: 13%

16. Sorption and Biodegradation?
• 250- 2024 pg/g at the bottom
Acetaminophen
Sand
Sand
Soil
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Sand
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Soil
Sorption (sterile)
Aerobic
Anaerobic
16
Leaching: 6%

17. Sorption or Biodegradation?
• 134-5109 pg/g in the middle
Sulfamethoxazole
Sand
Sand
Soil
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Sand
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5 10 15 20 25
Ct/C0
Time (d)
Soil
Sorption (sterile)
Aerobic
Anaerobic
17
• Mechanisms of EC attenuation in the drainfield may include a combination
of sorption and degradation in the vadose zone
Leaching: 3%

18. 18
Septic drainfieldsEC
TransportEffluent
Septic tank
• Are EC applied with effluent are attenuated in septic
drainfields before effluent reaches shallow groundwater?
Research Objective #2:
Transport to Shallow Groundwater

19. 19
Drip Dispersal
Gravel Trench
0.3 m gravel
layer
Methods: Construction of Large Drainfields
P
L
Tensiometer
Lysimeter
Piezometer
Lysimeter
Piezometer
Tensiometer
• 120 L/day/drainfield (~3 L/ft2/day)
in 6-doses at 4-hr intervals
T

20. Drip Dispersal System
30 cm Sand
15 cm Sand
Natural Soil
Drip line
with emitters
Instruments
• Tensiometers: 0.3, 0.6, 1.1 m
• Suction lysimeters: 0.3, 0.6, 1.1 m
• Piezometers: upto 3.7 m

21. Gravel Trench System
30 cm Sand
30 cm Gravel
15 cm Sand
Natural Soil
Drip line with
emitters
Instruments
• Tensiometers: 0.3, 0.6, 1.1 m
• Suction lysimeters: 0.3, 0.6, 1.1 m
• Piezometers: upto 3.7 m

22. 22
Transport from Effluent to Groundwater
Sulfamethoxazole
Mean = 4,242 ng/L
61.5
44.5 9.0
Bisphenol‐A
327.9
42.3 30.4
ND
Acetaminophen
12.814
61.6
316.8
n = 30
Carbamazepine
57.3
14.7 15.8
1.5

23. • Do emerging contaminants persist in the
watersheds that drain areas served by septic
systems?
River SedimentsECWastewater
23
Research Objective # 3:
Persistence in Stream Sediments

24. 37 32
12
24
14
39
66
71
25
35 23 24
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Buckhorm Creek
Bell Creek
English Creek
Turkey Creek
North Prong
Fishhawk Creek
South Prong
Forest Agricultural Pasture Mined Urban
Land Use
12‐37% 1‐24% 2‐23% 0‐66% 4‐71%
24
270, 000 acre
Alafia River watershed, FL
WWTP: No No No One One No No
Septic: 0.37 0.12 0.10 0.11 0.57 0.007 0.034
Methods: Sampling Locations

25. Summary: EC in the Sediments
Concentrations (ng/g)
South
Prong
North
Prong 1
English
Creek
Turkey
Creek
North
Prong 2
Buckhorn
Creek
Bell
Creek
Fishhawk
Creek 1
Fishhawk
Creek 2
Total (ng/g) 61.9 41.2 4.2 1.2 1.2 18.8 1.5 0.7 0.5
Acetaminophen
Caffeine
Carbamazepine
Diphenhydramine
Lidocaine
Nicotine
Pseudoephedrine
Trimethoprim
25
Yang, Y. Y.; Toor, G. S.; Williams, C. F. 2015. Pharmaceuticals and organochlorine pesticides in
sediments of an urban river in Florida, USA. Journal of Soils and Sediments. 15 (4): 993‐1004.

26. 39
66
71
24
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Buckhorm Creek
Bell Creek
English Creek
Turkey Creek
North Prong
Fishhawk Creek
South Prong
Forest Agricultural Pasture Mined Urban
Land use
WWTP: No No No One One No No
Septic: 0.37 0.12 0.10 0.11 0.57 0.007 0.034
Summary: EC in the Sediments
• Septic systems and the WWTP are the main sources.
26

27. 27
Summary
• EC are present in effluent and septic
drainfields
• Conc. decreased as effluent percolated in
vadose zone
• Mechanisms of EC attenuation in the drainfield
depend on the compound and include sorption
and/or degradation
• Septic systems contribute EC in rural and
urbanizing watersheds

28. 28
Extension Education (Continuing…)
• Presentations: “Managing EC in the Environment” in
2015 Tri-Country Water Summit and at other extension
events
• Extension factsheets: :Pharmaceuticals and Personal
Care Products”. “Trace Organics in Septic Systems”.
Available at http://edis.ifas.ufl.edu
• Training: In-service training at the Extension Professional
Association of Florida Annual Conference in Sept. 2015
• Citizens Education: Local magazines: “In the Field”