xvEPA
United States
Environmental Protection
Agency
Wastewater Technology Fact Sheet
Disinfection for Small Systems
DESCRIPTION
The impact of untreated and partially treated
domestic wastewater on rivers and community
water sources continues to raise health and safety
concerns. The organisms of concern in domestic
wastewater include enteric bacteria, viruses, and
protozoan cysts. Table 1 summarizes the most
common microorganisms found in domestic
wastewater and the types of human diseases
associated with them. Based on health and safety
concerns associated with microorganisms present in
wastewater, EPA has increased its efforts to address
the wastewater treatment needs of all communities
across the United States. As a result, small
community wastewater treatment needs are an EPA
priority.
According to the EPA, a small system can either be
a septic system, sand filter, or any system that
serves individual houses or groups of homes, strip
malls, or trailer parks. These systems can handle
flows from 3.8 to 76 m3/d (1,000 - 20,000 gpd).
EPA estimates that more than 20 million homes in
small communities are not connected to public
sewers and that nearly one million homes in small
communities across the United States have no form
of sewage treatment at all (USEPA, 1999). In
addressing small community needs, disinfection is
considered a primary mechanism for
inactivating/destroying pathogenic organisms and
preventing the spread of waterborne diseases to
downstream users and the environment. Some of
the most commonly used disinfectants for
decentralized applications include chlorine, iodine,
and ultraviolet (UV) radiation.
Wastewater must be adequately treated prior to
disinfection in order for any disinfectant to be
effective. Reduction of suspended solids (SS) and
biological oxygen demand (BOD) is recommended
prior to disinfection. SS may absorb UV radiation,
shield microorganisms, and increase chlorine
demand. Removing SS also reduces the number of
TABLE 1 INFECTIOUS AGENTS
POTENTIALLY PRESENT IN UNTREATED
DOMESTIC WASTEWATER
Organism
Disease Caused
Bacteria
Escherichia coli
Leptospira (spp.)
Salmonella typhi
Salmonella (=2100
serotypes)
Shigella (4 spp.)
Gastroenteritis
Leptospirosis
Typhoid fever
Salmonellosis
Shigellosis (bacillary
dysentery)
Cholera
Vibrio choleras
Protozoa
Balantidium coli Balantidiasis
Cryptosporidium parvum Cryptosporidiosis
Entamoeba histolytica Amebiasis (amoebic
dysentery)
Giardia lamblia
Helminths
Ascaris lumbricoides
Taena solium
Trichuris trichiura
Viruses
Giardiasis
Ascariasis
Taeniasis
Trichuriasis
Enteroviruses Gastroenteritis, heart
(72 types) e.g., polio echo anomalies, meningitis
and coxsackie viruses
Hepatitis A virus
Norwalk agent
Rotavirus
Infectious hepatitis
Gastroenteritis
Gastroenteritis
Source: Adapted from Crites and Tchobanoglous (1998), with
permission from The McGraw-Hill Companies.
microorganisms present. Organic compounds
associated with BOD also consume added chlorine.
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This fact sheet focuses on the use of UV
disinfection and chlorination to disinfect small
community septic systems.
APPLICABILITY
Chlorination and UV radiation can be used to
inactivate potentially infectious organisms. As a
result, communities and homeowners should
carefully select a disinfection technology. A
number of factors to consider when choosing a
disinfection system are presented in Table 2.
The effectiveness of a UV disinfection system
depends on the characteristics of the wastewater,
the intensity of UV radiation, the amount of time
the microorganisms are exposed to the radiation,
and the reactor configuration. Disinfection success
in any decentralized system is directly related to the
concentration of colloidal and particulate
constituents in the wastewater.
The most common UV system used for small
systems is a low-pressure, low-intensity system.
Low-pressure signifies the pressure of the mercury
in the lamp, which is typically 13.8 Pa
(0.002 lbs/in2). The term intensity refers to the
lamp power. Standard low-pressure, low-intensity
lamps typically have a power of 65 watts. These
lamps are generally efficient in producing
germicidal wavelengths necessary for damaging
DNA in bacteria. The low-pressure, low-intensity
lamp typically has 40 percent of its output at
253.7 nm, which is within the ideal range for
inactivating bacteria. This type of system can be
configured vertically or horizontally. This allows
systems to be configured to fit the available space.
Safety considerations associated with UV
disinfection include UV light itself, and potential
release of mercury from lamp bulbs if damaged.
Chlorine is one of the most practical and widely
used disinfectants for wastewater. Chlorination is
commonly used because it can kill disease-causing
bacteria and control nuisance organisms such as
iron-reducing bacteria, slime, and sulfate-reducing
bacteria. Chlorine destroys target organisms by
oxidizing the cellular material of bacteria. Chlorine
can be supplied in many forms and in liquid, solid,
or gaseous phases. Common chlorine-containing
disinfection products include chlorine gas,
TABLE 2 APPLICABILITY OF
CHLORINATION AND UV RADIATION
Consideration
Chlorination UV Radiation
Size of plant
Applicable level of
treatment prior to
disinfection
Equipment
reliability
Process control
Relative
complexity of
technology
Transportation on
site
Bactericidal
Virucidal
Cysticidal
Fish toxicity
Hazardous
byproducts
Persistent
residual
Contact time
Contribute
dissolved oxygen
Reacts with
ammonia
Increased
dissolved solids
pH dependent
Operation and
maintenance
sensitive
Corrosive
All sizes
All levels, but
chlorine required
will vary
Good
Well developed
Simple to
moderate
Substantial
Good
Poor
Poor
Potentially toxic
Yes
Long
Long
No
Yes
Yes
Yes
Minimal
Yes
Small to
medium1
Secondary
Fair to good
Fairly well
developed
Simple to
moderate
Minimal
Good
Good
Variable2
Nontoxic
No
None
Short
No
No
No
No
Moderate
No
Source: Adapted from U.S. EPA, 1986.
1 Early installations of UV disinfection facilities took place
primarily in small to medium size plants because the
technology was relatively new. Plants currently in design or
construction phases tend to be larger.
2 Recent studies have shown that UV radiation may be
effective against oocysts.
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hypochlorite solutions, and chlorine compounds in
solid or liquid form. Liquid sodium hypochlorite
and solid calcium hypochlorite tablets are the most
common forms of chlorine used for small systems
because they are less hazardous than chlorine gas.
ADVANTAGES AND DISADVANTAGES
UV Radiation
Advantages
• Effective inactivation of most viruses,
bacteria, and spores. May be effective against
some cysts.
• Physical process rather than a chemical
disinfectant.
• No residual effect that could harm humans or
aquatic life.
• Equipment requires less space than other
methods.
Disadvantages
• Low dosages may not effectively inactivate
some viruses, spores, and cysts.
• Turbidity and total suspended solids (TSS) in
the wastewater can render UV disinfection
ineffective.
• May require a large number of lamps.
Chlorination
Advantages
• Chlorine is reliable and effective against a
wide spectrum of pathogenic organisms.
• Chlorine is more cost-effective than UV or
ozone disinfection.
• The chlorine residual that remains in the
wastewater effluent can prolong disinfection
even after initial treatment and can be
measured to evaluate the effectiveness.
• Dosing rates are flexible and can be
controlled easily.
Disadvantages
• The chlorine residual is toxic to aquatic life
and the system may require dechlorination,
even when low concentrations of chlorine are
used.
• All forms of chlorine are highly corrosive
and toxic. Thus, storage, shipping, and
handling chlorine poses a risk and requires
increased safety - especially in light of the
new Uniform Fire Code.
• Chlorine reacts with certain types of organic
matter in wastewater, creating hazardous
compounds (e.g., trihalomethanes).
• Chlorine residuals are unstable in the
presence of high concentrations of chlorine-
demanding materials (BOD). Thus,
wastewater with high BOD may require
higher chlorine doses for adequate
disinfection.
DESIGN CRITERIA
UV Radiation
A UV disinfection system consists of mercury arc
lamps, a contact vessel, and ballasts. The source of
UV radiation is either a low- or a medium-pressure
mercury arc lamp with low or high intensity.
Medium- pressure lamps are generally used for
large facilities. The optimum wavelength to
effectively inactivate microorganisms is in the
range of 250 to 270 nm. The intensity of the
radiation emitted by the lamp dissipates as the
distance from the lamp increases. Low-pressure
lamps emit essentially monochromatic light at a
wavelength of 253.7 nm. Standard lengths of the
low-pressure lamps are 0.75 and 1.5m (2.5 and 5.0
ft), with diameters of 15 to 20 mm (0.6-0.8 inches).
The ideal lamp wall temperature is between 35 and
50°C (95-122°F). The United States Public Health
Service requires that UV disinfection equipment
have a minimum UV dosage of 16,000 //W-s/cm2.
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There are two types of UV disinfection reactor
configurations: contact and noncontact. In both
types, wastewater can flow either perpendicular or
parallel to the lamps. In the contact reactor, a series
of mercury lamps are enclosed in quartz sleeves to
minimize the cooling effects of the wastewater.
Flap gates or weirs are used to control the level of
the wastewater. In the noncontact reactor, UV
lamps are suspended outside a transparent conduit
which carries the wastewater to be disinfected. In
both types of reactors, a ballast—or control
box—provides a starting voltage for the lamps and
maintains a continuous current.
Because of capital cost advantages at low flow rates
and the ease of managing a system with a small
number of lamps, the majority of UV systems
handling less than 0.4 m3/s (1 MGD) are low-
pressure, low-intensity systems. A 0.4 m3/s
(1 MGD) system should have fewer than 100 low-
pressure lamps, so the impact of further reducing
the number of lamps will not be substantial. Figure
1 presents a schematic of a low pressure contact
UV disinfection system.
Several wastewater characteristics must be
evaluated before selecting UV disinfection as a
treatment method. The following list of
characteristics can affect the performance and
design of a UV disinfection system:
• Flow Rate: Wastewater flow can vary daily
and seasonally, affecting the required size of
a UV disinfection facility. As a result, the
peak hourly flow rate typically is used as the
design flow rate. The applied UV dosage is
a function of UV intensity and the duration of
exposure; the dosage rate achieved is directly
proportional to flow rate.
• UV Transmittance: UV transmittance is a
measure of the quantity of UV light at the
characteristic wavelength of 253.7 nm
transmitted through wastewater per unit
depth. Historically, a 50 percent UV
transmittance has been accepted as the
minimum transmittance for which UV
disinfection is practical. High turbidity
and/or high concentrations of BOD, certain
metals, TDS, TSS, and color may decrease
transmittance, lessening the effectiveness of
UV radiation.
• TSS Concentration: TSS levels significantly
affect UV disinfection because UV light can
be blocked by suspended solids. This can
Flow
Flap gate
level
control
UV vertical lamp
module with
support rack
Source: Crites and Tchobanoglous, 1998.
FIGURE 1 LOW PRESSURE CONTACT UV DISINFECTION SYSTEM
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shield microorganisms from the disinfecting
effects of the light. As a result, measuring
the particle size distribution in wastewater
can be helpful in determining the feasibility
of this disinfection technology. Particles
with a diameter of <10 microns allow for
easy UV penetration. Particles with
diameters between 10 and 40 microns can be
completely penetrated, but with increased
UV demand.
Microorganism Concentration: UV
disinfection performance evaluations indicate
that the microorganism density remaining
after exposure to a given UV dose is
proportional to initial microorganism density.
As a result, it is beneficial to consider the
concentration of microorganisms before
disinfection.
Hardness: Carbonate deposition (scaling) on
lamp sleeves becomes an issue when
handling wastewater with high levels of
hardness. Carbonate accumulation on lamp
sleeves reduces the intensity of UV light
reaching the wastewater.
Iron Concentration: Dissolved iron
concentrations in wastewater can absorb UV
light, reducing the light intensity reaching the
microorganisms. Adsorbed iron on
suspended solids may also shield
microorganisms from UV light. Iron
hydroxides may precipitate on lamp bulbs,
decreasing their intensity.
Organics: Dissolved organics or oils and
grease can reduce UV transmittance. The
size of the organic compounds is important in
determining whether they will interfere with
the UV transmittance: the larger the
molecular weight of the compounds, the
more they will interfere. This effect is
primarily the result of increasing color and/or
turbidity in the water.
Inorganics: Some inorganic salts (e.g.,
bromide) can absorb UV light and thereby
reduce UV effectiveness.
Systems using an aerobic household wastewater
treatment system are usually installed at or below
grade level and the effluent pipe may be as much as
60 cm (24 in) below grade. To maintain gravity
flow, the UV unit must be below grade and must
have very low flow resistance. During
construction, the components of an underground
UV system must be easily accessed for service and
low voltage should be used for safety.
Chlorination
For optimum performance, a chlorine disinfection
system should provide rapid initial mixing and a
plug flow contact regime. The goal of proper
mixing is to enhance disinfection by initiating a
reaction between free chlorine and ammonia
nitrogen. This helps to prevent free chlorine from
reacting with organic carbon compounds and
forming hazardous byproducts. In order to allow
appropriate time for the disinfection reaction, the
contact chamber should be designed with rounded
corners to eliminate dead flow areas. It should also
be baffled to minimize short-circuiting. This
design allows for adequate contact time between
the microorganisms and a minimal chlorine
concentration for a specific period of time.
Figure 2 illustrates plug flow chlorine contact
basins.
Chemical feed systems are used for adding sodium
and/or calcium hypochlorite solutions. For sodium
hypochlorite, the basic components of a chemical
feed system include a plastic or fiber glass storage
reservoir, metering pumps, and an injection device
to inject the hypochlorite solution into a contact
tank or pipeline. Calcium hypochlorite can
typically be added to the wastewater either by
mixing calcium hypochlorite powder in a mixing
device and then injecting it into the wastewater
stream, or by immersing chlorine tablets in the
wastewater using a tablet chlorinator. Tablet
chlorinator systems are described in more detail
below.
A typical calcium hypochlorite tablet chlorinator
consists of a cylindrical PVC tank with a diameter
ranging from 230 to 610 mm (9-24 in) and a height
ranging from 0.6 to 1.2 m (24-48 in). A sieve plate
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Source: Crites and Tchobanoglous, 1998.
FIGURE 2 TYPICAL PLUG FLOW
CHLORINE CONTACT BASINS FOR
SMALL FLOWS
with holes supports the 80 mm (3-in) diameter
calcium hypochlorite tablets. Tablet chlorinator
systems can typically provide between 1 and
295 kg (2-650 Ibs) of chlorine per day. A side
stream from the main flow is piped into the
chlorinator at the bottom of the tank. The flow
rises through the holes in the sieve plate, contacting
and eroding the bottom layer of tablets. The tablets
erode at a predictable rate based on the amount of
water that enters the chlorinator. An accurate
chlorine dosage can be achieved by controlling the
water flow rate through the chlorinator. The
chlorinator effluent is returned to the main stream,
providing the desired level of available chlorine to
meet operational requirement.
The required degree of disinfection can be achieved
by varying the dose and the contact time for any
chlorine disinfection system. Chlorine dosage will
vary based on chlorine demand, wastewater
characteristics, and discharge requirements. The
dose usually ranges from 5 to 20 mg/L. Table 3
describes some common wastewater characteristics
and their impact on chlorine. Several other factors
TABLE 3 WASTEWATER PROPERTIES
AFFECTING CHLORINATION AND UV
DISINFECTION PERFORMANCE
Property
Ammonia
Nitrite
Nitrate
Bio-
chemical
oxygen
demand
(BOD)
Hardness
Humic
materials,
Iron
PH
TSS
Effects on
Chlori nation
Effects on UV
Disinfection
Forms chloramines
when combined
with chlorine.
Reduces
effectiveness of
chlorine and results
inTHMs.
Minor effect, if any.
Organic
compounds
associated with
BOD can consume
added chlorine.
Minor effect, if any.
Minor effect, if any.
Minor effect, if
any.
At high
concentrations
may absorb UV
light and reduce
transmittance.
At high
concentrations
may absorb UV
light and reduce
transmittance.
Minor effect, if
any. If a large
portion of the BOD
is humic and/or
unsaturated (or
conjugated)
compounds, then
UV transmittance
may be
diminished.
Affects solubility of
metals that can
absorb UV light.
Can lead to the
precipitation of
carbonates on
quartz tubes.
High absorbency
of UV radiation.
Affects distribution Affects solubility of
between
hypochlorous acid
and hypochlorite
ions and among
the various
chloramine
species.
Shielding of
embedded bacteria
and chlorine
demand.
metals and
carbonates, and
thus scaling
potential.
Absorbs UV
radiation and
shields embedded
bacteria.
Source: Adapted from Darby, et al., 1995, with permission
from the Water Environment Research Foundation.
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ensure optimum conditions for disinfection,
including temperature, alkalinity, and nitrogen
content. Wastewater pH affects the distribution of
chlorine between hypochlorous acid and
hypochlorite. A lower pH favors hypochlorous
acid, which is a better disinfectant. High
concentrations of hypochlorous acid, however, may
result in production of chlorine gas, which may be
hazardous.
PERFORMANCE
Performance of chlorination and UV disinfection
varies between facilities based on maintenance
techniques and wastewater characteristics.
Researchers at Baylor University are evaluating
existing on-site systems using different disinfection
units.
OPERATION AND MAINTENANCE
UV Radiation
A routine operation and maintenance (O&M)
schedule should be developed and implemented for
any disinfection system. A proper O&M program
for a UV disinfection system should ensure that
sufficient UV radiation is transmitted to the
organisms to inactivate them. All surfaces between
the UV radiation and the target organisms must be
cleaned, while ballasts, lamps, and the reactor must
be functioning properly. Inadequate cleaning is one
of the most common causes of ineffective UV
systems. The quartz sleeves or Teflon tubes should
be cleaned regularly, either manually or through
mechanical methods. Common cleaning methods
include mechanical wipers, ultrasonic baths, or
chemicals. Cleaning frequency is site-specific.
Chemical cleaning is most commonly performed
with citric acid or commercially available cleaning
solutions. Other cleaning agents include mild
vinegar solutions and sodium hydrosulfite. A
combination of cleaning agents should be tested to
find those that are most suitable for the specific
wastewater characteristics without producing
harmful or toxic by-products. Non-contact reactor
systems are most effectively cleaned with sodium
hydrosulfite.
Average lamp life ranges from 8,760 to 14,000
working hours (between approximately 12 and 18
months of continuous use), but lamps are usually
replaced after 12,000 hours of use. Operating
procedures should be set to reduce the on/off cycles
of the lamps, because repeated cycles reduce their
effectiveness. In addition, spare UV lamps should
be kept on hand at all times along with accurate
records of lamp use and replacement. The UV
output gradually decreases over the life of the lamp
and the lamp must be replaced based on the hours
of use or a UV monitor. The quartz sleeves that fit
over the lamps will last about 5 to 8 years but are
generally replaced every 5 years.
The ballast must be compatible with the lamps and
should be ventilated to prevent excessive heating,
which may shorten its life or even result in fires.
The life cycle of ballasts is approximately 10 to
15 years, but they are usually replaced every
10 years.
Operation and maintenance of an on-site system is
usually the responsibility of the homeowner, but
some home sewage systems are sold with service
contracts that call for a trained serviceman to
inspect the system and perform necessary
maintenance every six months. As a result, it is
necessary to determine who is responsible for
operation and maintenance of the UV system.
Chlorination
O&M for a chlorine disinfection system should
include the following activities:
• Follow all manufacturer recommendations
and test and calibrate equipment as
recommended by the manufacturer.
• Disassemble and clean system components,
including meters and floats, every six
months.
Inspect and clean valves and springs
annually.
• If the system includes metering pumps,
maintain pumps on a regular basis.
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• Remove iron and manganese deposits with
muriatic acid or other removal agents.
If gaseous chlorine is stored on-site,
develop an emergency response plan in case
of accidents or spills.
It is essential to properly and safely store all
chemical disinfectants when using chlorine. The
storage of chlorine is strongly dependent on the
compound phase. Heat, light, storage time, and
impurities such as iron accelerate the degradation
of sodium hypochlorite. Calcium hypochlorite is
unstable under normal atmospheric conditions and
should be stored in a dry location. Hypochlorites
are destructive to wood, corrosive to most common
metals, and will irritate skin and eyes if there is
contact. For further details on the safe use and
storage of chlorine refer to the Material Safety Data
Sheets (MSDS) for the specific chemicals of
interest. MSDSs are readily available from the
internet by doing a search on the chemical name.
COSTS
The costs associated with chlorination and UV
treatment are predominantly dictated by dosage,
which in turn is related to peak flows, suspended
solids, temperature and bacterial counts. The
following summaries describe some of the costs
that a homeowner and/or community may
encounter when considering chlorination or UV
treatment to disinfect wastewater.
UV Radiation
Table 4 provides capital cost summaries for UV
systems. Systems include the wastewater channel,
UV module assemblies with lamps and quartz
sleeves, and ballasts. The ballasts include meters
for run times and UV intensity. The last two
systems in the table also include costs for delivery
of the equipment to the site.
Chlorination
Most decentralized systems use chlorine tablets to
disinfect their wastewater because they are simple
to use, and they are less expensive than liquid
chlorine. These units can range from $325-$700,
depending on the flow to be chlorinated. Tablets
TABLE 4 UV SYSTEM COSTS
UV System description
Cost
Peak flow: 19 m3/d (5,000 gpd)
Peak flow: 95 m3/d (25,000 gpd)
Peak flow: 49 m3/d (12,960 gpd)
Peak flow: 98 m3/d (25,920 gpd)
$2,5001
$3,7501
$4,0002
$4,7002
Sources:
1 Tipton Environmental International, Inc., 2003.
2 Infilco Degremont, Inc., 1999.
are sold in tablets or drums based on weight. For
example, a 100 kg (45 Ib) pail of tablets ranges in
cost from $69-$280, depending on the vendor.
Liquid chlorinators are more complex because the
liquid must be pumped into the system. A
hypochlorinator system sized to treat a flow range
of 9.5 to 76 m3/d (2,500 to 20,000 gpd), consisting
of one 210-L (55-gal) polyethylene drum, two
metering pumps, and injector valve, costs
approximately $4,200.
Cost Comparison
Cost comparisons between UV and chlorination
disinfection systems are difficult because of the
cost differences based on the volume of flow. In
addition, while the initial capital costs of one
system may be low relative to another system,
subsequent operation and maintenance costs for
each type of system must be evaluated before the
overall cost-effectiveness of one system vs. another
can be determined. For example, while the capital
costs of a chlorination system may be low
compared to the capital costs for a UV system,
dechlorination equipment and supplies will increase
the overall cost associated with this disinfection
method.
REFERENCES
Other Related Fact Sheets
Chlorine Disinfection
EPA 832-F-99-062
September 1999
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Ultraviolet Disinfection
EPA 832-F-99-064
September 1999
Other EPA Fact Sheets can be found at the
following web address:
http ://www. epa. gov/owm/mtb/mtb fact, htm
1. Chemical Feeding Technologies, Inc., 2003.
Information from website at
http ://www. chemfeedtech. com/.
2. Country Waters, Inc., Culpeper, Virginia,
1999. C. Jepson, personal communication
with Parsons, Inc.
3. Crites, R. and G. Tchobanoglous, 1998.
Small and Decentralized Wastewater
Management Systems. The McGraw-Hill
Companies. New York, New York.
4. Darby, J., M. Heath, J. Jacangelo, F. Loge,
P. Swaim, and G. Tchobanoglous, 1995.
Comparison of UV Irradiation to
Chlorination: Guidance for Achieving
Optimal UV Performance. Water
Environment Research Foundation.
Alexandria, Virginia.
5. Eddington, G., 1993. Plant Meets Stringent
Residual Chlorine Limit. Water
Environment & Technology, pp. 11-12.
6. Fahey, R. J., 1990. The UV Effect on
Wastewater. Water Engineering &
Management. Vol. 137, No. 12, pp. 15-18.
7. Hanzon, B.D. and R. Vigilia, 1999. UV
Disinfection. Wastewater Technology
Showcase. Vol. 2, No. 3, pp. 24-28.
8. Horentstein, B., T. Dean, D. Anderson, and
W. Ellgas, 1993. Dechlorination at
EBMUD: Innovative and Efficient and
Reliable. Proceedings of the Water
Environment Federation 66th Annual
Conference and Exposition. Anaheim,
California.
9. Infilco Degremont, Inc., Richmond,
Virginia, 1999. P. Neofotistos, Applications
Engineer, personal communication with
Parsons, Inc.
10. Jesperson, K., 1999. "Ultraviolet
Disinfection Gains Popularity." Internet site
at [http://www.pwmag.com/uv.htm].
accessed September 1999.
11. Jet, Inc., 2003. Sales Department, personal
communication with Parsons, Inc.
12. Kwan, A., J. Archer, F. Soroushian, A.
Mohammed, and G. Tchobanoglous, 1996.
"Factors for Selection of a High-Intensity
UV Disinfection System for a Large-Scale
Application." Proceedings from the Water
Environment Federation (WEF) Speciality
Conference: Disinfecting Wastewater for
Discharge and Reuse. WEF. Portland,
Oregon.
13. Metcalf & Eddy, Inc., 1991. Wastewater
Engineering: Treatment, Disposal, and
Reuse. 3d ed., The McGraw-Hill Companies.
New York, New York.
14. Reed, D., 1998. "Selecting Alternatives to
Chlorine Disinfection." Internet site at
[http://www.manufacturing.net/magazine/p
olleng/archives/1998/po!0901.98], accessed
September 1999.
15. Task Force on Wastewater
Disinfection, 1986. Wastewater Disinfection.
Manual of Practice No. FD-10. Water
Environment Federation. Alexandria,
Virginia.
16. Tipton Environmental International Inc.,
Milford, Ohio, 2003. S. Tipton, personal
communication with Parsons, Inc.
17. Tramfloc, Inc., 2003. Information from
website at http://www.tramfloc.com/.
18. U.S. EPA, 1986a. Design Manual:
Municipal Wastewater Disinfection. EPA
Office of Research and Development.
Cincinnati, Ohio. EPA/625/1-86/021.
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19. U.S. EPA, 1986b. Disinfection with
Ultraviolet Light—Design, Construct, and
Operate for Success. Cincinnati, Ohio.
20. U.S. EPA, 1988. Ultra Violet Disinfection:
Special Evaluation Project. EPA Region 5.
Chicago, Illinois.
21. U.S. EPA, 1999. U.S. Census Data on Small
Community Housing and Wastewater
Disposal and Plumbing Practices. EPA 832-
F-99-060.
The mention of trade names or commercial
products does not constitute endorsement or
recommendation for use by the U.S. Environmental
Protection Agency.
Office of Water
EPA 832-F-03-024
September 2003
22. U.S. EPA, 2002. Onsite Wastewater
Treatment Systems Manual. EPA 625-R-OO-
008.
ADDITIONAL INFORMATION
Trojan Technologies, Inc.
David Tomowich
3020 Gore Road
London, Ontario N5 V 4T7
PPG Industries, Inc.
Tablet Chlorination Systems
Joanne Funyak
1 PPG Place 3 6N
Philadelphia, PA 15272
National Small Flows Clearinghouse
P. O. Box 6064
West Virginia University
Morgantown, WV 26506-6064
US Filter/Water & Tiernan
John Barnstead
1901 West Garden Road
Vineland, NJ 08360
The Chlorine Institute, Inc.
Tracey W. Kerns
2001 L Street, N.W., Suite 506
Washington, D.C. 20036
For more information contact:
Municipal Technology Branch
U.S. EPA
1200 Pennsylvania Avenue, NW
Mail Code 4204M
Washington, D.C. 20460
* 2002 *
THE YEAR OF
CLEAN WATER
MTB
Excellence in compliance through optimal technical jolutions
MUNICIPAL TECHNOLOGY BRAfftfH
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