rem21475

REMEDIATION Summer 2016
Nanotechnology Approach for Removing
Hydrocarbons and Other Contaminants
From Utility Vault and Substructure
Wastewater
Allan D. Pronovost
The feasibility of a nanotechnology-based hydrocarbon and other contaminants removal pressure
filtration device has been demonstrated for dewatering industrial utility vaults and substructures
for discharge to local storm drains. The use of the filter device facilitated compliance of utility
companies with the General National Pollutant Discharge Elimination System (NPDES) Permit for
Discharges from Utility Vaults and Substructures to Waters of the United States. The filter device,
employing agglomerated oleophilic nanomaterials demonstrated the removal of dissolved priority
pollutants, total suspended solids, and hexane extractable materials below U.S. Environmental Pro-
tection Agency criteria with an overall efficiency of 97.4 percent. Overall reduction per contaminant
averaged 90 percent. c⃝ 2016 Wiley Periodicals, Inc.
INTRODUCTION
Utility vault and substructure dewatering and discharge have become more difficult as
the minimum allowable threshold limit has been revised by the U.S. Environmental
Protection Agency (EPA) and State of California regulatory agencies to include a large
quantity of priority pollutants as part of National Pollutant Discharge and Elimination
System (NPDES) Permits for point sources that discharge into waters of the United States
(Federal Water Quality Order WQ 2014-0174-DWQ, General Permit number
CAG990002, July 1, 2015, General National Pollutant Discharge Elimination System
Permit [NPDES] for Discharge from Utility Vaults and Underground Structures to Waters
of the United States, California State Water Resources Control Board, 2015). These new
regulations, issued by the State of California under federal authority, and became effective
on July 1, 2015. As California has set precedence by being the first state to comply with
the federal requirements, it is expected that numerous other states will follow suit.
These permits have required the use of vacuum trucks to remove storm water runoff
that collects in utility vaults for transport to treatment and disposal facilities. In addition,
the use of in ground sump pumps has been prohibited in substructures. The outcome is
higher costs to utility companies for electrical power, which are passed on to customers.
c⃝ 2016 Wiley Periodicals, Inc.
Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/rem.21475 169

Nanotechnology Approach for Removing Hydrocarbons and Other Contaminants
In general, NPDES per-
mits require the removal
of all hexane extractable
materials (HEMs) such as
oil and grease, which in-
clude oil range organics
(ORO), diesel range or-
ganics (DRO), and gaso-
line range organics (GRO).
Dissolved pollutants are difficult, if not impossible, to remove from utility vault
wastewater under routine field conditions. This is based on the lack of field deployable
filtration devices designed to remove the broad spectrum of priority pollutants present in
utility vault wastewater, and designed to also work with the smaller volumes of water that
accumulate in such vaults. In general, NPDES permits require the removal of all hexane
extractable materials (HEMs) such as oil and grease, which include oil range organics
(ORO), diesel range organics (DRO), and gasoline range organics (GRO). In addition,
these permits require the removal of up to 126 suspended and/or dissolved priority
pollutants. These include volatile organic compounds (VOCs), semi-VOCs, polycyclic
aromatic hydrocarbons (PAHs), organochlorine pesticides, polychlorinated biphenyls
(PCBs), and toxic heavy metals. NPDES permits also require removal of total suspended
solids (TSS) above one micron in diameter. Removal of total dissolved solids below 1
micron in diameter is not a requirement of the permit.
Approaches of utility companies for removing pollutants from substructures have
historically been limited at best. The primary option is vacuum truck removal followed by
treatment for disposal and/or incineration. A variety of filters are available for sand and
debris removal and some are configured with polypropylene or polyester fabric, which
absorb a small amount of oil and grease, but they generally have proven ineffective for
pressure filtration of dissolved pollutants and toxic heavy metals to meet EPA mandated
discharge criteria.
The EPA requires nanomaterial adsorbents to remove oil and grease after field use.
The design, construction, and materials used for the pressure filter device allowed for
retention of the agglomerated nanomaterials, which averaged 3 microns in diameter,
thereby, enabling compliance with this EPA requirement.
For heavy metal removal, water-insoluble ceramic ion exchangers were utilized in the
lumen of the filter sac to afford a continuous back flush design. The filter sac material layers
were likewise constructed of polyester fiber of selected heavy bulk density to withstand up
to 400 gallons a minute (gpm) pressure and to afford an additional multilayered, oleophilic
barrier separation means for oil and grease for wastewater perfusion.
MATERIALS AND METHODS
A filter was designed to remove hydrocarbons and other contaminants from wastewater
and storm water runoff that accumulates in utility vaults and substructures. The filter
device utilizes a portable submersible pump. The system design incorporates the use of a
filter sleeve comprised of the following: A six-layer polyester fiber sleeve to capture HEMs
such as oil, diesel, and gasoline; an inner lumen ion exchange chamber for removing
selected toxic heavy metals; and a three-dimensional inner perfusion layer comprised of
agglomerated, oleophilic nanomaterials for removing dissolved contaminants, particularly
those on the priority pollutants list of the Clean Water Act.
Recent advances in materials science and nanotechnology have enabled the
production of highly oleophilic nanomaterials. For this study, three types of functionally
reactive, amorphous, hydroxyl-derived silica subparticulate nanostructure subassemblies
were prepared and utilized. Silica nanostructure subassemblies were further derivatized to
contain methyl, butyl, or tert-butyl groups with a surface density of 10 to 12 functional
moieties per square nanometer. The derivitized silica was agglomerated into a
170 Remediation DOI: 10.1002/rem c⃝ 2016 Wiley Periodicals, Inc.

Exhibit 1. Filter sleeve device under flow
supramolecular three-dimensional labyrinth, 3 microns in diameter, with a specific surface
area (Brunauer–Emmett–Teller, BET) of up to 400 square meters per gram (m2
/g). The
use of one and a half pounds of material per filter represented a total available reactive
surface area of 300,000 m2
or approximately 74 acres of reactive oleophilic nanomaterial
filter area per filter sleeve. To increase contact with the nanomaterial, a three-dimensional
perfusion sleeve design comprised of a construct of six oleophilic fabric layers one of
which contained the oleophilic nanomaterials. The three-dimensional design involved
construction of a filter sleeve that allowed for processing of wastewater by perfusion
through walls within the sleeve to which water was exposed under pressure filtration. The
design forced the flow of water through a one-inch layer of nanomaterial held and
cushioned between two fabric layers and the construction was such that pinholes and
points of possible leakage without perfusion filtration were eliminated. The size of the
pressure filtration device was 12 inches × 48 inches, fitted with a 2-inch cam lock for
connection to hosing used with portable utility vault pumps
Exhibit 1 shows the design of the completed hydrocarbon and contaminants removal
filter sleeve while in use under field discharge conditions from a utility vault.
Before field testing, an initial study for the filter sleeve device was performed that
involved filtering 500 gallons (1892.51 L) of water spiked with a variety of contaminants.
Pollutants were added (“spiked”) into a 5,000-gallon tank at target levels of 150 percent of
the EPA’s water quality criteria expressed in milligrams per liter (mg/L), micrograms per
liter (𝜇g/L), or nanograms per liter (ng/L) units depending upon the pollutant.
To test the device under controlled conditions, the following were added to a
500-gallon tank of water designed to simulate a vault: HEMs, 78 available priority
pollutants, selected toxic heavy metals, and silt at greater than 150 percent of the EPA
threshold water quality criteria as specified in the NPDES Permit.
A variety of HEMs were added to cover the full spectrum of hydrocarbon chain
lengths from 1 carbon to greater than 44-carbon chain length, complex grease, and waxes.
HEMs included asphalt, Stoddard solvent, Texas heavy crude oil (from Gulf Horizon
without dispersant), Pennsylvania light crude oil, pitch (roof tar), nonsynthetic grease,
diesel fuel, kerosene, jet A fuel, and gasoline.
To match EPA criteria on a 𝜇g/L (or other unit weight) basis, mass-based
standardization was used for sample spiking. In each case, the pollutant was added to
achieve target spike values of 150 percent EPA water quality criteria.
For solids in the high microgram total weight level, or higher, a Mettler-Toledo
balance with accuracy five decimal points past the gram level was used. Below the mid
c⃝ 2016 Wiley Periodicals, Inc. Remediation DOI: 10.1002/rem 171

Water samples were
collected before and after
treatment and submit-
ted to an independent
National Environmental
Laboratory Accreditation
Program (NELAP) certified
laboratory (Weck Labora-
tories, Los Angeles, CA)
for analysis following EPA
methods.
microgram total weight level, dilutions of solid in pre-prepared aqueous solutions or
appropriate solvent solutions were utilized.
For liquids, mass-based calculations were performed to account for the density of the
material to determine the relative mass. Then, the final weight was adjusted up or down if
liquid densities at 25 ◦
C were below or above the density of water (1.00 g/mL).
Prediluted chemicals in ampoules below the mid 𝜇g/L range were diluted serially in
water or appropriate solvent to achieve mass standardization. All dilutions were serial
10-fold and utilized Eppendorf pipettes. Pipette tips were changed between dilutions.
Filtration was facilitated at 117 gpm using a portable, submersible Power-Flo Pump
and Systems pump with two-inch cam lock and hose coupled to the filtration device.
Water samples were collected before and after treatment and submitted to an independent
National Environmental Laboratory Accreditation Program (NELAP) certified laboratory
(Weck Laboratories, Los Angeles, CA) for analysis following EPA methods.
EPA and other analytical procedures included the following:
• EPA Method 625 for semi-VOCs
• EPA Method 8081A for organochlorine pesticides,
• EPA Method 608 for organochlorine pesticides and PCBs
• APHA Method SM 4500 H+B for pH
• EPA Method 1664A for oil and grease (HEM)
• EPA Method SM 2500D for TSS
• EPA Method for 8015B for DRO/ORO TPH
• EPA Method 8015B for GRO TPH
• EPA Method 1631E for mercury (total, low-level)
• EPA Method 7470A for mercury
• EPA Method 200.7 metals plus calcium
• EPA Method 200.8 for toxic heavy metals
• EPA Method 8082 for PCBs
• EPA Method 8270C for semi-VOCs
• EPA Method 8260B for VOCs
• EPA Method 624 for VOCs
Some redundancy in pollutant testing among EPA methods was encountered in order
to account for all the priority pollutants tested.
Exhibit 2 shows the sampling containers used for collecting the prefiltered
contaminated water (left) and postfiltration water processed by the filter sleeve (right).
RESULTS
The overall results for the initial study on the filter sleeve were as follows: An overall
concordance of 98.5 percent was observed between filter sleeve and EPA Methods; 97.4
percent of all pollutants tested were equal to or below EPA water quality criteria after
filtration through the filter sleeve; the average percent reduction was 90 percent for all
pollutants; and the filter sleeve device exhibited structural integrity under pressure
pumping at 117 gpm.
Although multiple types of HEM were added, they were clumped into four permit
categories for reporting purposes; these categories were oil and grease, DRO, GRO, and

Exhibit 2. Pre- and postfiltration sampling containers
Exhibit 3. Overall concordance of filter sleeve to EPA water quality criteria analytical testing
Correct Positive Result
Spiked
Number in
Category Pollutants Tested <EPA Cutoff >EPA Cutoff
Average Percent
Reduction
Yes 78 HEM + priority pollutants 76 2 90
Correct Negative Result
Yes No
No 14 Toxic heavy metals 14 0
No 38 Priority pollutants: No
criteria, not spiked but tested
38 0
Percent positive concordance 97.4 2.6
Percent negative concordance 100
Overall concordance 98.5
ORO. In addition to TSS, 73 available dissolved pollutants were tested, giving a total of 78
permit categories of pollutants. Exhibit 3 shows that 76 of 78 categories of pollutants
were reduced below the EPA cutoff, and two were above the EPA limit. Of the 52
pollutants not spiked, all exhibited the expected not detectable (ND) result. As such, the
overall positive result (below EPA water quality criteria) concordance was 97.4 percent.
Overall concordance was 98.5 percent and the average percent reduction for all pollutants
spiked was 90 percent.

Exhibit 4. HEM analytical results compared to EPA water quality criteria
Action Levels
Parameter Units Minimum Daily Maximum Daily Spiked Final Result < EPA Cutoff
Oil and grease mg/L None 25 52.8 ND Y
pH Standard units 6 9 7.74
DRO mg/L None 2 132.1 0.79 Y
GRO 𝜇g/L None 5 58,180 0.002 Y
ORO 𝜇g/L No limit Unknown ND Y
TSS mg/L None 400 3,000 ND Y
Total tested 5
Percent below EPA limit 100
TOTAL PETROLEUM HYDROCARBONS
The concentrations of the four categories of HEM and TSS were below EPA criteria
following filter sleeve filtration. In spite of the extremely heavy contamination, especially
for GRO, all values were ND or trace, well below EPA criteria (see Exhibit 4).
PRIORITY POLLUTANTS
A total of 73 priority pollutants were tested in the filter sleeve initial study and 97.4
percent of the pollutants tested were below the EPA water quality criteria. Pollutant
concentrations were decreased equal to or below EPA water quality criteria when spiked
with 150 percent of the EPA water quality criteria or above, as in the case of HEM.
Results showed the majority of contaminants were ND (see Exhibit 5). Two pollutants,
2,4-dimethylphenol and 2,4,6-trichlorophenol, exhibited a decrease, but not below EPA
limits. There was no difference or trend in type of pollutant removed, and this covered the
spectrum from complex HEM contaminants to VOCs, PCBs, substituted hydrocarbons,
PAHs, and other contaminants.
TOXIC HEAVY METALS
The EPA’s priority pollutant list includes 14 toxic heavy metals. The criteria for eight
heavy metals are hardness-based and hence removal cannot be verified without analytical
quantitation of calcium. One pollutant (beryllium) does not have a water quality criterion
established (Exhibit 6). The filter sleeve is currently formulated with the dried form of ion
exchange media within the device for removing lead, mercury, and cadmium, but not
other heavy metals. This is based on the lack of availability of the preferred dried form of
ion exchange resins for these metals. Although no toxic heavy metals were spiked in the
initial study, testing was conducted according to EPA methods and all results indicated
negative or trace metal results as expected. The trace metal concentrations are likely
attributable to metals associated with HEM.

Exhibit 5. Priority pollutant removal results
NPDES Permit
Number Pollutant
Water Quality
Criteria (𝜇g/L)
Amount Spiked
(𝜇g/L)
Final
Result
< EPA
Cutoff
Percent
Reduction
17 Acrolein 780 1,170 NDa Y 100
18 Acrylonitrile 0.66 0.99 ND Y 100
19 Benzene 71 106.5 6.55 Y 93.8
20 Bromoform 360 540 85.5 Y 84.2
21 Carbon tetrachloride 4.4 6.6 ND Y 100
22 Chlorobenzene 21,000 31,500 2,700 Y 91.4
23 Chlorodibromomethane 34 51 11.5 Y 77.5
27 Dichlorobromomethane 46 69 21 Y 69.6
29 1,2-Dichloroethane 99 148.5 36.5 Y 75.4
31 1,2-Dichloropropane 39 58.5 7.45 Y 87.3
32 1,3-Dichloropropylene 1,700 2,550 160 Y 93.7
36 Methylene chloride 1,600 2,400 760 Y 68.3
37 1,1,2,2-Tetrachloroethane 11 16.5 2.4 Y 85.5
38 Tetrachloroethylene 8.85 13.28 ND Y 100
39 Toluene 200,000 300,000 6,500 Y 97.9
40 1,2-Trans-dichloroethylene 140,000 210,000 ND Y 100
42 1,1,2-Trichloroethane 42 63 15 Y 76.2
46 2,4-Dichlorophenol 790 1185 475 Y 60
47 2,4-Dimethylphenol 2,300 3,450 2,650 N 23.2
48 2-Methyl-4,6-dinitrophenol 765 1147.5 110 Y 90.4
49 2,4-Dinitrophenol 14,000 21,000 2,800 Y 86.7
55 2,4,6-Trichlorophenol 6.5 9.75 8.65 N 11.3
56 Acenaphthene 2,700 4,050 155 Y 96.2
58 Anthracene 110,000 165,000 1.35 Y 99.99
59 Benzidine 0.00054 0.00081 ND Y 100
60 Benzo(a)anthracene 0.049 0.0735 ND Y 100
61 Benzo(a)pyrene 0.049 0.0735 ND Y 100
62 Benzo(b)fluoranthene 0.049 0.0735 ND Y 100
66 Bis(2-chloroethyl)ether 1.4 2.1 ND Y 100
68 Bis(2-ethylhexyl)phthalate 5.9 8.85 1.25 Y 85.9
73 Chrysene 0.049 0.0735 ND Y 100
74 Dibenzo(a,h)anthracene 0.049 0.0735 ND Y 100
75 1,2-Dichlorobenzene 17,000 25,500 810 Y 96.8
79 Diethyl phthalate 120,000 180,000 31,500 Y 82.5
82 2,4-Dinitrotoluene 9 13.65 ND Y 100
85 1,2-Diphenylhydrazine 0.54 0.81 ND Y 100
86 Fluoranthene 370 555 3.3 Y 99.4

Exhibit 5. Continued
NPDES Permit
Number Pollutant
Water Quality
Criteria (𝜇g/L)
Amount Spiked
(𝜇g/L)
Final
Result
< EPA
Cutoff
Percent
Reduction
87 Fluorene 14,000 21,000 130 Y 99.4
88 Hexachlorobenzene 0.00077 0.00116 ND Y 100
89 Hexachlorobutadiene 50 75 ND Y 100
90 Hexachlorocyclopentadiene 17,000 1 ND Y 100
91 Hexachloroethane 8.9 13.35 ND Y 100
92 Indeno(1,2,3-cd)pyrene 0.049 0.0735 ND Y 100
93 Isophorone 600 ‘900 525 Y 41.7
95 Nitrobenzene 1,900 2850 1550 Y 45.6
96 N-nitrosodimethylamine 8.1 12.15 5.2 Y 57.2
97 N-nitrosodi-n-propylamine 1.4 2.1 ND Y 100
98 N-nitrosodiphenylamine 16 24 ND Y 100
102 Aldrin 0.00014 0.00021 ND Y 100
103 alpha-BHC 0.013 0.0195 ND Y 100
104 beta-BHC 0.046 0.069 ND Y 100
105 gamma-BHC 0.063 0.0945 0.063 Y 33
107 Chlordane 0.00059 0.00085 ND Y 100
109 4,4’-DDE 0.00059 0.00085 ND Y 100
110 4,4’-DDD 0.00084 0.00126 ND Y 100
111 Dieldrin 0.00014 0.00021 ND Y 100
112 alpha-Endosulfan 0.22 0.33 ND Y 100
113 beta-Endosulfan 0.22 0.33 ND Y 100
114 Endosulfan sulfate 110 166 ND Y 100
115 Endrin 0.81 5.7 ND Y 100
116 Endrin aldehyde 0.76 1.14 ND Y 100
117 Heptachlor 0.00021 0.00035 ND Y 100
118 Heptachlor epoxide 0.00011 0.00017 ND Y 100
119 PCB-1016 0.00366 ND Y 100
120 PCB-1221 0.00366 ND Y 100
121 PCB-1232 0.00017 0.00366 ND Y 100
122 PCB-1242 0.00366 ND Y 100
(Sum of PCBs) 0.00366 ND Y 100
123 PCB-1248 0.00366 ND Y 100
124 PCB-1254 0.00366 ND Y 100
125 PCB-1260 0.00366 ND Y 100
126 Toxaphene 0.00075 0.00113 ND Y 100
Number of priority pollutants 73
Percent of samples below EPA limit 97.3
Average percent reduction 90.7
aND means not detectable, analytical value was zero.

Exhibit 6. Toxic heavy metal removal results
NPDES
Permit
Number Pollutant
Water Quality
Criteria
Amount
Spiked
Final
Result
Correct
Negative
Result
1 Antimony 4,300 0 ND Y
2 Arsenic 340 0 ND Y
3 Beryllium No criteria 0 ND Y
4 Cadmium Hardness based 0 ND Y
5a Chromium (III) Hardness based 0 ND Y
5a Chromium (VI) 16 0 ND Y
6 Copper Hardness based 0 ND Y
7 Lead Hardness based 0 ND Y
8 Mercury 0.051 0 ND Y
9 Nickel Hardness based 0 ND Y
10 Selenium Hardness based 0 ND Y
11 Silver Hardness based 0 ND Y
12 Thallium 6.3 0 ND Y
13 Zinc Hardness based 0 ND Y
14 Cyanide 22 0 ND Y
PRIORITY POLLUTANTS—WITHOUT CRITERIA, NOT SPIKED, BUT
TESTED
Thirty-eight of the Priority Pollutant List chemicals were not spiked, but tested; and two
were untested (see Exhibit 7). These included 22 chemicals for which no water quality
criteria exists, eight hardness-based chemicals, and the balance were either not
commercially available, purchased but not received in time for the study, or purchased but
on backorder by the vendor. All these chemicals (except the two not tested) were analyzed
to assess if the laboratory results were correctly negative. All chemicals tested in this
category produced negative results with no trace levels detected.
PENTACHLOROPHENOL CRITERIA (PH-BASED)
The EPA established criterion for pentachlorophenol is based on pH (Exhibit 8). Although
pH adjustment was not a feature of the filter sleeve, pentachlorophenol was spiked and
tested and results were below EPA criterion at the Weck Laboratory measured pH value
of 7.74.

Exhibit 7. Priority pollutants—representing no water quality criteria, not spiked but tested, or spiked but not tested
NPDES Permit
Number Pollutant
Water Quality
Criteria
Amount
Spikeda (𝜇g/L)
Final
Resulta
Correct Negative
Result
15 Asbestos No criteria 0 NT NT
16 2,3,7,8-TCDD 0.000000014 0.000039 NT NT
24 Chloroethane No criteria 0 ND Y
25 2-Chloroethylvinyl ether No criteria 0 ND Y
26 Chloroform No criteria 0 4.1 IND
28 1,1-dichloroethane No criteria 0 ND Y
30 1,1-Dichloroethylene 3.2 NRec ND Y
33 Ethylbenzene 29,000 NRec 2.3 IND
34 Methyl bromide 4,000 NAvail ND Y
35 Methyl chloride No criteria 0 ND Y
41 1,1,1-Trichloroethane No criteria 0 ND Y
43 Trichloroethylene 81 BO ND Y
44 Vinyl chloride 525 BO ND Y
45 2-Chlorophenol 400 BO ND Y
50 2-Nitrophenol No criteria 0 ND Y
51 4-Nitrophenol No criteria 0 ND Y
52 3-Methyl-4-chlorophenol No criteria 0 ND Y
53 Pentachlorophenol pH based 0 ND Y
54 Phenol 4,600,000 BO ND Y
57 Acenaphthylene No criteria 0 ND Y
63 Benzo(ghi)perylene No criteria 0 ND Y
64 Benzo(k)fluoranthene 0.049 BO ND Y
65 Bis(2-chloroethoxy)methane No criteria 0 ND Y
67 Bis(2-chloroisopropyl)ether 170,000 NAvail ND Y
69 4-Bromophenyl phenyl ether No criteria 0 ND Y
70 Butylbenzyl phthalate 5,200 NAvail ND Y
71 2-Chloronaphthalene 4,300 NAvail ND Y
72 4-chlorophenyl phenyl ether No criteria 0 ND Y
78 3,3’-Dichlorobenzidine 0.077 NRec ND Y
80 Dimethyl phthalate 2,900,000 0 ND Y
81 Di-n-butyl phthalate 12,000 BO 1.1 IND
83 2,6-Dinitrotoluene No criteria 0 ND Y
84 Di-n-octyl phthalate No criteria 0 ND Y
94 Naphthalene No criteria 0 15.3 IND
99 Phenanthrene No criteria 0 ND Y
100 Pyrene 11,000 BO ND Y
101 1,2,4-Trichlorobenzene No criteria 0 ND Y
106 delta-BHC No criteria 0 ND Y
108 4,4’-DDT 0.00059 NAvail ND Y
Abbreviations: NT: not tested, ND: not detectable, BO: backordered, NRec: not received, NAvail: not available, Y: yes.

Exhibit 8. Pentachlorophenol criteria (pH-based)
pH Pentachlorophenol (𝜇g/L)
1 to 2 0.035
2 to 3 0.095
3 to 4 0.26
4 to 5 0.71
5 to 6 1.9
6 to 6.9 5.3
> 6.9 8.2
NONTESTED, NONSPECIFIED CONTAMINANTS OF CONCERN
The chemicals listed in Exhibit 9 could not be tested for the reasons presented in the
exhibit. These chemicals either have no water quality criteria, or do not appear on the
priority pollutant list at all, being not fully defined in the permit as to approximate toxic
level, chemical isoform, or relative risk posed to human health and the environment.
Some of these are chemicals also outside the scope of effective filtration technology and,
hence, could not be expected to show concentration reductions as a result of the filter
sleeve treatment (i.e., radionuclides).
FIELD TESTING
The hydrocarbon and contaminants removal filter was tested on numerous substructures
and utility vaults in conjunction with a Southern California utility company. Results from
one representative vault are summarized herein. The contents of a 5,000-gallon vacuum
truck used to pump a utility vault were transported on the day of collection to a contained
testing site. Prefiltration water samples were obtained and processed separately under
chain of custody. Contents of the truck were filtered through a filter sleeve under a
pressure of up to 400 gpm and postfiltration samples were collected following chain of
custody procedures for the same analyses performed in the initial study.
Results are shown in Exhibit 10. Only those contaminants that were either detected
in the vault water or were of special interest are shown. Contaminants tested by EPA
methods that were not detected are not shown.
Of the 30 contaminants shown in Exhibit 10, four are below EPA criteria, one is above
its EPA criterion (bis(2-ethylhexyl)phthalate), which was found to be a contaminant from
a filter sleeve carrier bag material that is no longer used, eight contaminants were not on
the priority pollutant list, 10 contaminants were hardness based and, thus, were not
evaluated because hardness was not measured, six contaminants were reported, but were
not detected, and one contaminant was on the permit priority pollutant list but had no
specified water quality criteria.
All other vaults tested gave comparable results (data not shown).

Exhibit 9. Nontested pollutants of concern
Category Pollutant
NPDES
Permit
Levels
Unknown
Removal
Technology
Unknown
Hardness
or pH
Based
Beyond
Filter
Sleeve
Capability
Peptides Pyrethrins * *
Organophosphates * *
Biostimulating substances * *
Nutrients Ammonia * *
Nitrate * *
Phosphorous * *
Metals Antimony *
Beryllium * *
Cadmium *
Chromium III *
Chromium IV *
Copper *
Nickel *
Selenium *
Silver * *
Thallium *
Zinc *
Cyanide *
Chemicals Xylene *
Chlorine *
Pentachlorophenol *
Others Dissolved oxygen *
pH *
Radionuclides *
Calcium hardness * *
Smell/odor/color/taste *
CONCLUSIONS
The study demonstrated the feasibility of the nanotechnology-based hydrocarbon and
contaminants removal filter designed specifically for utility vaults and substructures
dewatering for discharge to local sewers and drains under simulated conditions at levels
well above those typically found in utility vaults screened in southern California since
2012 and in utility vaults and substructures in the field. Discharge of filtered water
complied with EPA mandated levels. The filter sleeve was shown as a means of providing
protection to the beneficial uses of the waters of the United States as well as achieving
compliance with the enhanced requirements of the NPDES Permits for the reduction of

Exhibit 10. Field utility vault test results
Pollutant Untreated Treated Units
Water
Quality
Criteria Final Resolution
TSS 230 74 mg/L 400 Below EPA limit
DRO 0.2 0.6 mg/L 2 Below EPA limit
Cu 46 20 𝜇g/L Hardness based
Pb 14 12 𝜇g/L Hardness based
Ni 11 4.7 𝜇g/L Hardness based
Ch 0.0082 ND 𝜇g/L 16 Below EPA limit
Cu 0.058 0.027 𝜇g/L Hardness based
Pb 0.017 0.014 𝜇g/L Hardness based
Ni 0.015 0.0056 𝜇g/L Hardness based
Ag ND 0.0033 𝜇g/L Hardness based
Zn 0.75 0.75 𝜇g/L Hardness based
MTBE 3.6 3.7 𝜇g/L – Not on priority pollutant list
Acetone 11 11 𝜇g/L – Not on priority pollutant list
MTBE 3.3 3.2 𝜇g/L – Not on priority pollutant list
Bis(2-ethylhexyl) phthalate 16 13 𝜇g/L 5.9 False positive
Diethyl phthalate 1.2 1.2 𝜇g/L 120,000 Below EPA limit
pollutants from storm water runoff collected in utility vaults and substructures. Use of the
filter sleeve will also aid in reducing use of vacuum trucks, reduction in transportation and
disposal fees, shortening downtime and costs of electrical power grid rerouting for
prolonged periods of time, as well as reducing labor costs and delays for utility companies.
Two dissolved pollutants of the 73 tested from the Permit priority pollutant list were
reduced but not below EPA levels. These included 2,4-dimethylphenol and
2,4,6-trichlorophenol. Yang (2003) noted that 2,4-dimethylphenol was irreversibly bound
by activated carbon. Second, 2,4,6-trichlorophenol has been shown to be adsorbed by
activated carbon (Bansal & Goyal, 2005; Garner et al., 2001; Krishnaiah et al., 2013;
Tumsek et al., 2015) and by Faujasite-type zeolite (Zhang et al., 2014). As such, to
remove these two priority pollutants, future embodiments of the filter sleeve technology
will incorporate activated carbon within the lumen of the filter sleeve.
REFERENCES
Bansal, R. C., & Goyal, M. (2005). Activated carbon adsorption. Boca Raton, FL: CRC Press; Taylor and Francis
Group.
California State Water Resources Control Board (2015). Order WQ 2014-0174-DWQ, General Permit number
CAG990002, October 21, 2014, General National Pollutant Discharge Elimination System Permit
(NPDES) for discharge from utility vaults and underground structures to waters of the United States.
Sacramento, CA: Author.

Garner, I. A., Watson-Clark, I. A., Kirkwood, R., & Senior, E. (2001). Dual solute adsorption of
2,4,6-trichlorophenol and N-(2-(2,4,6-trichlorophenoxy)propyl)amine on to activated carbon. Journal of
Chemical Technology and Biotechnology, 46(9), 932–940.
Krishnaiah, D., Anisuzzaman, S. M., Bono, A., & Sarbatly, R. (2013). Adsorption of 2,4,6-trichlorophenol (TCP)
on activated carbon. Journal of King Saudi University: Science, 25(3), 251–255.
Tumsek, F., Bayinder, Z., Bodur, G., & Koyuncu, Z. (2015). Adsorption of 2,4,6-trichlorophenol on activated
carbon. Journal of the Turkish Chemical Society, Section A: Chemistry, 2(3), 22–24.
Yang, R. T. (2003). Adsorbents, fundamentals and applications. Hoboken, NJ: John Wiley & Sons.
Zhang, Y., Mancke, R. G., Sabelfeld, M., & Geiben, S. U. (2014). Adsorption of trichlorophenol on zeolite and
adsorption regeneration with ozone. Journal of Hazardous Materials, 271, 178–184.
Allan D. Pronovost, PhD, is chief scientific officer of Red Lion Chem Tech, LLC in San Diego, California. His
focus is in the area of environmental remediation. Dr. Pronovost received his PhD in biological sciences from the
University of Rhode Island and did his postdoctoral education at Yale University.

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