United States
Environmental Protection
                         Wastewater Technology Fact Sheet
                         Disinfection for Small Systems

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

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
                                DOMESTIC WASTEWATER
Disease Caused
                        Escherichia coli
                        Leptospira (spp.)
                        Salmonella typhi
                        Salmonella (=2100
                        Shigella (4 spp.)
Typhoid fever
Shigellosis (bacillary
                        Vibrio choleras
                        Balantidium coli          Balantidiasis
                        Cryptosporidium parvum   Cryptosporidiosis
                        Entamoeba histolytica     Amebiasis (amoebic
                        Giardia lamblia
                        Ascaris lumbricoides
                        Taena solium
                        Trichuris trichiura

                        Enteroviruses            Gastroenteritis, heart
                        (72 types) e.g., polio echo  anomalies, meningitis
                        and coxsackie viruses
                        Hepatitis A virus
                        Norwalk agent
Infectious hepatitis
                        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.

This  fact  sheet  focuses  on  the use of UV
disinfection  and chlorination to disinfect  small
community septic systems.


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,
 Chlorination    UV Radiation
 Size of plant
 Applicable level of
 treatment prior to


 Process control
 complexity of

 Transportation on




 Fish toxicity



 Contact time

 dissolved oxygen

 Reacts with

 dissolved solids

 pH dependent

 Operation and

   All sizes
 All levels, but
chlorine required
   will vary

Well developed
   Simple to




 Potentially toxic









 Small to

Fair to good
 Fairly well

 Simple to













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.

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.

UV Radiation


•    Effective   inactivation  of  most  viruses,
     bacteria, and spores. May be effective against
     some cysts.

•    Physical process  rather than  a chemical

•    No residual effect that could harm humans or
     aquatic life.

•    Equipment requires less space  than  other


•    Low dosages may not effectively inactivate
     some viruses, spores, and cysts.

•    Turbidity and total suspended solids (TSS) in
     the wastewater can render UV disinfection

•    May require a large number of lamps.



•    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.


•    The chlorine residual is toxic to aquatic life
     and the system may require dechlorination,
     even when low concentrations of chlorine are

•    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


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.

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
       Flap gate
                                                                   UV vertical lamp
                                                                   module with
                                                                   support rack
    Source: Crites and Tchobanoglous, 1998.

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

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.


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

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

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

 Source: Crites and Tchobanoglous, 1998.

               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

             Effects on
             Chlori nation
                  Effects on UV
             Forms chloramines
             when combined
             with chlorine.

             effectiveness of
             chlorine and results
             Minor effect, if any.
             associated with
             BOD can consume
             added chlorine.
Minor effect, if any.
Minor effect, if any.
                  Minor effect, if
At high
may absorb UV
light and reduce

At high
may absorb UV
light and reduce

Minor effect, if
any. If a large
portion of the BOD
is humic and/or
unsaturated (or
compounds, then
UV transmittance
may be

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
hypochlorous acid
and hypochlorite
ions and among
the various

Shielding of
embedded bacteria
and chlorine
                               metals and
                               carbonates, and
                               thus scaling
Absorbs UV
radiation and
shields embedded
Source: Adapted from Darby, et al., 1995, with permission
from the Water Environment Research Foundation.

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


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


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
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.


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

       Inspect  and  clean valves  and springs

•       If the system  includes metering pumps,
       maintain pumps on a regular basis.

•      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.


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.


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
         UV System description
  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)



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


Other Related Fact Sheets

Chlorine Disinfection
EPA 832-F-99-062
September  1999

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,
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      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,
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      Comparison  of   UV  Irradiation  to
      Chlorination:   Guidance  for  Achieving
      Optimal   UV  Performance.   Water
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      Alexandria, Virginia.

5.     Eddington, G., 1993. Plant Meets Stringent
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6.     Fahey,  R.  J.,  1990. The  UV Effect  on
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      Management. Vol.  137, No. 12, pp. 15-18.

7.     Hanzon, B.D. and  R. Vigilia, 1999.  UV
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      Showcase. Vol. 2, No. 3, pp. 24-28.

8.     Horentstein, B., T.  Dean, D. Anderson, and
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9.     Infilco   Degremont,  Inc.,   Richmond,
      Virginia, 1999. P. Neofotistos, Applications
     Engineer,  personal  communication  with
     Parsons, Inc.

10.   Jesperson,   K.,   1999.   "Ultraviolet
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     accessed September 1999.

11.   Jet, Inc., 2003.  Sales Department, personal
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12.   Kwan,  A., J. Archer,  F.  Soroushian, A.
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     Conference:  Disinfecting  Wastewater for
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13.   Metcalf & Eddy, Inc., 1991. Wastewater
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14.   Reed, D., 1998. "Selecting Alternatives to
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     September 1999.

15.   Task   Force    on   Wastewater
     Disinfection, 1986. Wastewater Disinfection.
     Manual of Practice  No.  FD-10.  Water
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16.   Tipton  Environmental  International  Inc.,
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17.   Tramfloc,  Inc., 2003.   Information  from
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18.   U.S.   EPA,   1986a.  Design   Manual:
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19.   U.S.   EPA,   1986b.   Disinfection  with
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20.   U.S. EPA, 1988. Ultra Violet Disinfection:
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21.   U.S. EPA, 1999.  U.S. Census Data on Small
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      Disposal and Plumbing Practices. EPA 832-
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-

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
                                                       Excellence in compliance through optimal technical jolutions
                                                       MUNICIPAL TECHNOLOGY BRAfftfH