v>EPA
United States
Environmental Protection
Agency
Office of Water
Washington, D.C.
EPA 832-F-99-034
September 1999
Combined Sewer Overflow
Technology Fact Sheet
Chlorine Disinfection
DESCRIPTION
Combined sewer overflows (CSOs) tend to occur
during periods of rainfall or snowmelt, when total
wastewater flows exceed the capacity of the
combined sewer system (CSS) and/or treatment
facilities. When this occurs, the CSS is designed to
overflow directly to surface water bodies, such as
lakes, rivers, estuaries, or coastal waters. These
overflows can be a major source of water pollution
in communities served by CSSs.
CSOs typically discharge a variable mixture of raw
sewage, watershed runoff pollutants, and scoured
materials that build up in the collection system
during dry weather periods. These discharges
contain pollutants that may adversely impact the
receiving water body. These pollutants range from
suspended solids, pathogenic microorganisms,
viruses, and cysts, to chemical and floatable
materials. Dermal contact with the discharge or
ingestion of water or contaminated shellfish may
result in health risks.
Consistent with the U.S. Environmental Protection
Agency (EPA) 1994 CSO Control Policy, cities
with CSSs are implementing controls that will
provide for attainment of water quality standards
that protect the beneficial use of streams and other
receiving water bodies. To help meet site-specific
bacterial water quality standards, pathogenic
bacteria in the CSO discharge will most likely
require inactivation or destruction. The process of
selective inactivation and/or destruction of
pathogenic microorganisms is known as
disinfection.
CSO disinfection occurs through the reduction of
solids and through the oxidation or radiation of
pathogens. Physical reduction of bacteria in CSOs
is accomplished through sedimentation, flotation
and filtration, while common chemical oxidizing
agents include chlorine, bromine and hydrogen
peroxide or their compounds. In addition to
chemical oxidants, there are several alternative
disinfectants, such as ultraviolet light (UV) radiation
and ozonation. These are further described in the
EPA CSO Technology Fact Sheet 832-F-99-020,
Alternative Disinfectants for Treating CSOs. The
remainder of this fact sheet focuses on chlorine as a
CSO disinfectant.
Chlorine may be applied to a CSO in either a
gaseous form (C12) or as an ionized solid
[Ca(OCl)2,NaOCl]. Each compound reacts in water
to produce the disinfectants HOC1 (hypochlorous
acid) and OC1" (hypochlorite ion) as illustrated in
Figure 1. Together, these compounds contribute to
what is know as the CSO's free residual chlorine
concentration. As chlorine is added to the CSO, it
reacts with ammonia and organic matter to form
chloramines and chloro-organic compounds. The
addition of more chlorine oxidizes some of the
chloro-organic compounds and chloramines,
resulting in the conversion of monochloramines to
dichloramines and trichloramines.
C12 + H2O
Ca(OCl)2 -
NaOCl
- HC1
Ca2+
Na+
+ HOC1
2OC1-
OC1
FIGURE 1 COMMON REACTIONS OF
CHLORINE PRODUCTS
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As more chlorine is added, the residual chloramines
and chloro-organic compounds are reduced to a
minimum value and free chlorine residuals result.
The point at which the formation of residual
chlorine compounds occurs is known as the
"breakpoint." Thus, the term "breakpoint
chlorination" describes the process whereby
sufficient chlorine is added to the CSO to obtain a
free chlorine residual. If sufficient chlorine cannot
be added to achieve the breakpoint reaction and
thus ensure that disinfection of the CSO is occurring
through saturation with chlorine, care should be
taken to ensure that disinfection is occurring
through extended chlorine contact time with the
CSO (see discussion of the relationship of
disinfection dose vs. contact time below).
Various theories have been put forth to explain the
germicidal effects of chlorine. These include
oxidizing the germ cells, altering cell permeability,
altering cell protoplasm, inhibiting enzyme activity,
and damaging the cell DNA and RNA. Chlorine
appears to react strongly with lipids in the cell
membrane, and membranes having high lipid
concentrations appear to be more susceptible to
destruction. For this reason, viruses, cysts, and ova
are more resistant to disinfectants than are bacteria.
The predominant disinfection mechanism will
depend on the microorganism in question, the
wastewater characteristics, and the chlorine
compound used. When the physical parameters
controlling the chlorination process are held
constant, the germicidal effects of chlorine as
measured by bacterial survival depend primarily on
dosage (and form) and the contact time. It has been
found that increasing either dosage or contact time,
while simultaneously decreasing the other, can
achieve approximately the same degree of
disinfection. When breakpoint chlorination is
practiced properly, the bactericidal effect is
considered good and viricidal effect is considered
moderate.
APPLICABILITY
The selection of a disinfection method for a specific
CSO outfall depends on many factors, including:
the quality of the wastewater being discharged; any
potential toxic effects; the ease of operation and
maintenance; and any regulations governing residual
standards.
As discussed above, the disinfection capability of a
system is heavily dependant on the contact time
between the chlorine and bacteria. Because
suspended solids can inhibit the disinfecting agent
from reacting with the bacteria, disinfection is
usually used in conjunction with an additional
technology that specifically reduces the suspended
solids in solution.
DESIGN CRITERIA
CSO disinfection systems must be designed to
handle variable pollutant loadings and large
fluctuations in flow. Because CSOs are intermittent
and are characterized by short durations and
relatively large flow rates relative to base sewage
flow, bacterial and organic loadings from the
collection system may vary greatly, both within and
between storm events. Loadings can be extremely
variable from the beginning to the end of a wet
weather event. The beginning of a CSO event will
typically exhibit high solids and bacterial loadings as
the system is flushed. The concentration of
pollutants will typically trail off as the storm event
continues. Loadings will also be affected by the
characteristics of the watershed, the dynamics of the
collection system, the antecedent dry weather
conditions, and the regional rainfall rate. A CSO
disinfection system should be designed with site-
specific loading characteristics in mind, and should
be capable of handling a large first-flush pollutant
load.
The intended or designated use of the receiving
water body may also affect the disinfection process
design. For example, the presence of sensitive
aquatic species may limit the allowable residual
disinfectant concentrations in the receiving water,
thereby limiting the amount of disinfectant that can
be added to the CSO.
An additional baseline consideration for the
successful design of a CSO disinfection process is
solids reduction. Since bacteria embedded in
paniculate matter can be shielded from the
disinfectant, solids must be removed from the CSO
to ensure effective disinfection. Therefore, even if
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the water quality requirements for the receiving
water body do not dictate the need for solids
reduction, the disinfection process itself may require
it.
After these general considerations are resolved, the
designer can begin to evaluate specific disinfection
processes to determine which potential processes
may be most appropriate. Generally, disinfection
processes can be broken into "high rate" processes
and extended detention processes. High rate
processes using breakpoint chlorination (described
above) are often chosen over extended-detention
systems because the cost differences between the
systems are minor (the two systems have similar
capital costs, but the high rate systems often incur
additional O&M costs for chemicals and power),
and the decreased retention time characteristic of
the high rate processes makes them more attractive.
In order to design a breakpoint chlorination system,
it may be necessary to determine the amount of time
that the chlorine must be in contact with the CSO to
achieve the desired disinfection. This "contact
time," or CT, relationship should be developed for
treatment of the design CSO event for a significant
antecedent dry weather period. This will likely
provide worst case conditions for determining vessel
size and disinfectant supply rate.
The reactor should be designed for as close to ideal
plug flow as possible and should include effective
initial mixing of the chlorine solution. Strong initial
mixing is critical in high rate disinfection processes
where contact times are short. Mixing occurs
through mechanical means (mixers, pumps,
spargers) or through the utilization of the energy
available in the storm water gradient (hydraulic
jumps, flumes, high velocity segments).
As discussed above, control of the chlorine
disinfection process for CSOs is complicated
because of the highly variable nature of the flow.
Measurement of the CSO flow rate is therefore
critical in determining the rate at which to add
disinfectant. Often a combination of weirs or flumes
(for lower flows) and open channel flow
measurement (for high flows) is required to cover
the varying flow rates. Sonic devices, bubblers, and
pressure-type level sensors have all been used in
conjunction with flumes, weirs and open channels to
measure CSO rates and volumes. In addition,
because CSO chlorine disinfection will typically
include short contact times (one to ten minutes), be
applied to relatively dirty water, and operate
intermittently, the use of feedback systems and
chlorine residual analyzers to pace the chemical feed
is difficult. Membrane and probe type chlorine
monitors have been used, but neither has been
proven to date to be effective and reliable.
A flow-paced control system with a fixed
chlorination feed concentration has been found to be
simpler and more reliable than feedback-based
systems, although flow-paced systems will require
some trial and error adjustment after installation to
develop proper dosage-to-flow relationships.
Chlorine feed rate is based on the required dosage
and the flow rate.
The flow-paced system may result in higher chlorine
residual concentrations relative to feedback-based
systems. While these higher residual concentrations
may be more effective at inactivation of viruses,
spores and cysts, these residuals and their various
chlorinated byproducts can have an adverse impact
on the quality of the receiving waters. Although
chlorine dissipates rapidly downstream of the
application point, in some cases it may be necessary
to dechlorinate the disinfected effluent to protect the
receiving water bodies. Gaseous sulfur dioxide or
liquid sodium bisulfite can be used for this purpose
and dechlorination is achieved at almost
instantaneous contact times. Control system
difficulties similar to those described for the flow-
paced chlorination system can lead to overdosing of
dechlorination chemicals.
Several chlorine forms can be used to provide
disinfection. When choosing a form of chlorine for
a specific application, consideration should be given
to safety, stability, availability, deodorizing ability,
corrosiveness, solubility and ability to respond
instantaneously to initiation and rate changes.
Because of concerns over accidental releases in
developed areas or from unstaffed facilities, gaseous
chlorine is not utilized as frequently in CSO
applications as is liquid chlorine. However, gaseous
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chlorine may be appropriate for use in CSO
treatment facilities that are located at Wastewater
Treatment Plants (WWTPs) because the chlorine
application can be carefully monitored. Gaseous
chlorine-based systems will require evaporator
equipment and potable water, and possibly chemical
scrubbing facilities.
The most common forms of chlorine used in CSO
applications are chlorine gas, sodium hypochlorite,
and calcium hypochlorite. The following
paragraphs describe these compounds in more
detail.
Liquid forms of chlorine appear to be the most
appropriate choice for wet weather treatment
because they are comparatively easy to handle
relative to other forms of chlorine, such as gaseous
chlorine. In general, liquid chlorine will be applied
from on-site chemical storage tanks using metering
pumps. Because of potential problems in delivering
liquid chlorine to remote sites after suppliers' hours,
chlorine should be stored on-site. The chlorination
system should have adequate on-site storage
capacity to feed the design dosage for the design
overflow event. Extra volume may also be stored to
allow for chemical degradation. Feed equipment
should be sized to deliver the required dose under
peak flow conditions. Consideration of the time
required to replenish chlorine should be factored
into sizing of storage tanks.
Chlorine gas:
Gaseous chlorine (C12) is relatively inexpensive and
has the lowest production and operating costs for
large continuous disinfection operations. It is a
stable compound which may be stored for an
extended period of time, but only as a liquefied gas
under high pressure. Storage containers vary in size
from 150 pound cylinders to 55 ton tank cars. The
size of the storage containers used at any given site
will be dependent upon the facility design as well as
the anticipated treatment capabilities of the system.
Because chlorine gas is hazardous, it should not be
stored in areas accessed by the public and any
transportation of the gas should be continuously
monitored. Chlorine gas is extremely toxic and
corrosive and because it is such a strong oxidant, it
reacts with almost any organic material found in
wastewater. Organics, ammonia, and phenolic
compounds will often react with the chlorine before
it has a chance to react with pathogens. For
example, chlorine reacts with ammonia to form
chloramines and phenols to form chlorophenols.
Chloramines and chlorophenols are referred to as
combined chlorine residuals and together with free
chlorine residuals constitute the total residual
chlorine (TRC). Therefore, use of chlorine gas
should be closely monitored to ensure its
effectiveness as a disinfectant.
Sodium hypochlorite:
Chlorine may also be supplied as sodium
hypochlorite (NaOCl), otherwise known as liquid
bleach. Sodium hypochlorite can be generated from
sodium hydroxide and chlorine, or it can be
generated electrolytically from brine. Sodium
hypochlorite can be manufactured on site, or it can
be purchased in liquid form generally containing 3 to
15 percent available chlorine. Decay of the original
product will occur as a result of exposure to light,
an increase in temperature, or because of
concentration of the compound. Product decay
occurs more rapidly at higher concentrations;
therefore sodium hypochlorite is typically stored as
a 5 percent solution of available chlorine. Sodium
hypochlorite should be stored at temperatures below
85 degrees Fahrenheit in a corrosion-resistant tank.
Sodium hypochlorite is the most expensive of the
three forms of chlorine compounds. It produces a
free chlorine residual, and forms chloramines and
chlorophenols. Sodium hypochlorite is safer to
handle than gaseous chlorine, and can be generated
and stored on site.
Calcium hypochlorite:
Chlorine may be supplied in the form of calcium
hypochlorite, Ca(OCl)2, in either wet or dry form.
High grade calcium hypochlorite contains at least 70
percent available chlorine, and is readily soluble in
water. It is a strong oxidizer and is extremely
hazardous. Calcium hypochlorite tends to be
unstable and therefore should be stored in a dry
place inside a corrosion-resistant container in order
to reduce product breakdown. Like chlorine gas
and sodium hypochlorite, calcium hypochlorite
breaks down into free chlorine residuals and will
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react to form chloramines and chlorophenols.
Calcium hypochlorite is more expensive than
chlorine gas and will degenerate as a result of
storage. Calcium hypochlorite also crystallizes and
can clog pipes, pumps, and valves.
ADVANTAGES AND DISADVANTAGES
A long record of historical data has shown that
chlorine is the best and most successful means of
disinfecting water. Clean drinking water is a global
necessity and the residual addition of chlorine to
water in controlled amounts prevents the spread of
life-threatening diseases and the growth of living
organisms.
However, chlorine disinfection also has its
disadvantages. Numerous toxicity studies have
shown adverse effects due to chlorination (Rein,
1992; Hall, 1981; Ward, 1978). Any discharge of
chlorinated effluent into a receiving water body
may involve some release of chlorine residuals and
chlorine byproducts. Free chlorine and combined
chlorine residuals are toxic to aquatic life at certain
concentrations. The lethal effects of free chlorine
are more rapid and occur at lower concentrations
than chloramines. Chlorine will also react with
organic material to form trace amounts of
chlorinated hydrocarbons called trihalomethanes
(THMs). THMs are suspected as being carcinogens
and are strictly monitored in drinking water.
Environmental variables affecting the toxicity of
residual chlorine include pH and temperature of the
receiving water. Due to increases in available free
chlorine, toxicity increases with decreasing pH.
Toxicity also tends to increase with increasing
temperature. Mean acute toxicity values for several
species are given in Table 1.
Intermittent discharges of total residual chlorine
have been recommended not to exceed 0.2
milligrams per liter for a period of 2 hours per day
where more resistant species of fish are known to
persist, or 0.04 milligrams per liter for a period of 2
hours per day for trout or salmon (Brungs, 1973).
In addition, chlorine may inadvertently enhance the
growth of pathogenic microorganisms in receiving
waters, since chlorine breaks large protein
molecules into small proteins, peptides, and other
TABLE 1 ACUTE VALUES FOR
CHLORINE TOXICITY
Species
Freshwater
Daphnia magna
Fathead minnow
Brook trout
Bluegill
Saltwater:
Menidia
Mysid
Mean Acute Value ( g/l)
27.66
105.2
117.4
245.8
37
162
Source: U.S. EPA, 1985.
amino acids that can be more readily used by
coliform bacteria.
Using chlorine as a disinfectant does have certain
health and safety limitations that should be
evaluated before implementing any CSO plan. The
transport of chlorine can pose serious hazards and
in some states, transport of chlorine is severely
restricted. Some of the health risks include:
Irritation of mucous membranes, respiratory
tract and eyes.
• Prolonged exposure to the gas may cause
coughing, gagging, and may result in
pulmonary edema and death.
• Gaseous chlorine has a tendency to
hydrolyze in the presence of moisture,
forming hydrochloric acid, which irritates the
eyes and skin.
Liquid chlorine removes body heat, freezing
exposed skin.
• It should be noted, however, that sodium
hypochlorite is considered to be safe for
storage and handling in systems for remote
disinfection of CSOs, and there is currently
no definitive scientific evidence that the
intermittent use of chlorine for CSO
disinfection poses a significant environmental
risk.
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PERFORMANCE
The performance of a CSO disinfection system
depends on its ability to kill bacteria, viruses, and
other pathogenic organisms. In CSOs with low
suspended solids concentrations, pathogens are
killed with a quick dose of disinfectant. However,
when suspended solids concentrations in the CSO
are high, the disinfection process is controlled by
two different mechanisms. The initial disinfection
phase kills individual and small clumps of bacteria.
The majority of the bacterial kill occurs in this step;
however, residual bacteria entrapped in solids are
usually not affected. The amount of bacteria
remaining in the CSO after the initial disinfectant
dose is a function of the concentration of suspended
solids and their particle sizes. If low levels of
bacteria are required to meet the treatment
objectives, the disinfection process may require a
higher level of solids removal, longer contact times,
or larger disinfectant dosages to kill these remaining
bacteria. The first two of these options will require
larger treatment vessels.
Disinfection performance is often assessed through
changes in concentrations of indicator organisms
(primarily fecal and total coliform) over time. This
assessment is often made using mathematical
equations that predict future concentrations of
indicator organisms based on system-specific
variables. For example, the Collins model predicts
the reduction in bacterial concentration as a function
of chlorine residual concentrations and system
contact time according to the following equation:
-3
where:
Y, = Y0 (1+0.23CT)
Yt = bacterial concentration after time T
(MPN/lOOml)
Y0= original bacterial concentration
(MPN/lOOml)
C = chlorine residual concentration after
time T (mg/1)
At lower values of CT, a modified model (Collins-
Selleck) was developed to define the relationship
between Y/Y0 and CT. Several other factors,
including the chlorine dose, contact time, flow
characteristics, and mixing intensity, also influence
the effectiveness of chlorine disinfection.
As described above, the effectiveness of chlorine in
disinfecting CSOs is usually measured in terms of its
effect on reducing fecal coliform or total coliform
bacteria. Table 2 presents the results of several
studies that evaluated the effectiveness of chlorine
gas in reducing pathogens from CSOs and simulated
CSOs.
OPERATION AND MAINTENANCE
Maintenance for a CSO treatment facility is typically
performed similarly to maintenance performed at a
batch operation. Properly designed facilities will
operate automatically; however, after a storm event,
most facilities will require maintenance to remove
residuals (screenings, floatables & grit) and to check
and replenish chemical supplies. Maintenance of
disinfection equipment can occur during the post-
event visit and includes the following:
All copper tubing from lines and fittings must
be checked routinely. The lines can be
checked for corrosion by bending them; if the
lines give off a screeching noise when they
are bent, they are corroded and the tubing
must be replaced.
• Tubing and vessels should be checked
routinely for moisture accumulation or metal
discoloration, both of which are signs of
incipient leak development.
Evaporator vessels should be inspected for
sludge accumulation either every year or
after every 200 tons of chlorine use. Piping
and connections to the evaporator should be
inspected every six months.
T = contact time (min)
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TABLE 2 SUMMARY OF Cl, DISINFECTION DATA FROM STUDY LOCATIONS
Location
Dosage CI2
Total Coliform
Reduction
Fecal Coliform
Reduction
Other
Contact
Time
Philadelphia1 5 mg/l before: 1,000,000 units/
100 ml after: 5-10 units
/100ml
before: 1,000,000
units/100 ml after: 5-
10 units/100 ml
Philadelphia1
Philadelphia2
Grosse Point
Woods,
Michigan3
Grosse Point
Woods,
Michigan3
Lake
Onondaga,
New York4
Lake
Onondaga,
New York4
Lake
Onondaga,
New York4
Lake
Onondaga,
New York5
2.6 mg/l
5 mg/l
8.0-10.8
mg/l
1-5 mg/l
25 mg/l
25 mg/l
16 mg/l
0-24 mg/l
12 mg/l
12 mg/l
99.9% reduction
<200 units/1 00 ml
4 log reduction 4 log reduction
3-4 log reduction 3-4 log reduction
1 000 units/1 00 ml 200 units/1 00 ml 200/1 00 ml fecal
strep 5 log
reduction
poliovirus &
Sabin K-1 5 log
reduction
coliophage
200 units/1 00 ml 2min.
Fecal Strep
1000 units/1 00 ml
1-6 log reduction 5-9.8 mg/l
3-4 log reduction to CI2 residual
200 units/1 00 mg/l 5-8 mg/l
2-4 log reduction to CI2 residual
?00 units/100 mn/l
3 min.
4 min.
6 min.
2 min.
2 min.
1 min.
1 min.
1 min.
1. U.S. EPA, 1973.
2. U.S. EPA, 1974.
3. Rouge River National Wet Weather Demonstration Project, 1999.
4. U.S. EPA, 1975.
5. U.S. EPA, 1979.
The chlorine gas filter should be inspected
and the filter element should be replaced
every six months. At this time, the sediment
trap should also be washed and dried, and
lead gaskets should be replaced.
Chlorine pressure reducing valves should be
cleaned with isopropyl alcohol or
trichloroethylene. Spring valves should be
replaced every two to five years.
Ejectors should be cleaned every six
months.
• Booster pumps should follow regular pump
maintenance schedules.
To prevent any health threats, the facility using
chlorine should provide:
• Adequate ventilation.
• Safety equipment.
• Eye wash fountains and deluge showers.
• Emergency respiratory protection.
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• Emergency kits.
• Information and telephone numbers on the
Chlorine Institute and the Chlorine
Emergency Plan response team.
• Employee training for safe operations.
• Material Safely Data Sheets.
Finally, using chlorine in CSO applications may
present serious hazards. As mentioned previously,
chlorine is extremely corrosive. The following
recommendations do not cover every aspect of
chlorine safety, but should be considered when
designing a CSO chlorination facility:
• Facilities housing chlorine require heavy
ventilation at floor level, since chlorine gas
is heavier than air. Ventilation should
provide at least 60 air changes per hour.
• Chlorine leakage detection equipment
should be located near chlorinating
equipment.
• An emergency scrubbing system may be
installed to neutralize any leaking chlorine.
All storage and chlorinator equipment
should be separated from the rest of the
facility.
Chlorine storage tanks should not be
exposed to direct sunlight to avoid
overheating.
COSTS
Costs for designing a CSO treatment facility are
highly variable, and will depend on the number of
CSOs to be treated, the drainage area being served,
the anticipated fluctuation in flow rates, and the
sensitivity of the surrounding areas (residential or
habitat). Costs for a treatment facility may include
the following: planning costs, capital costs for
construction of the facility, chemical costs, and
yearly maintenance costs. The designer may reduce
capital costs by using one vessel or basin for both
suspended solids reduction and disinfection. As
most vendors typically base costs on flow
conditions, it is not practical to provide generalized
cost estimates for a chlorination system in this fact
sheet. Chemical costs will fluctuate based on
current market prices. Chlorine gas delivered in a
2000 pound cylinder currently sells for $0.57 per
pound. A 25 percent solution of sodium
hypochlorite currently sells for $2.58 per pound.
Calcium hypochlorite can be purchased for $1.29
per pound. All chemicals delivered in containers
require a deposit which will vary depending on the
vendor. Table 3 summarizes some of the typical
costs that can be encountered by systems with
specific peak design flows.
TABLE 3 COST PROJECTIONS FOR CSO
DISINFECTION PILOT STUDY, SPRING
CREEK AWPCP UPGRADE
Peak Design Flow (cfs)
1,250 2,500 5,000
$854,000 $979,000 $1,142,000
Capital
Costs
Annualized
Capital $87,000 $100,000 $116,000
Costs
Annual
O&M Cost
$239,000 $239,000 $239,000
Total
Annualized $326,000 $339,000 $355,000
Costs
Source: NYDEP, 1997.
Notes:
1. Costs are present worth in 1997 dollars.
2. Capital costs are based upon sizing to meet peak design
flow and a 4-log reduction in fecal coliform.
3. Capital costs are for installation at Spring Creek and are
for process equipment only. Costs do not include
additional contact tankage (if required) or support
facilities.
4. Annual operating costs are based upon an assumed
typical 40 CSO events/year at a volume treated of 15
million gallons per event.
5. Annualized costs are based upon a period of 20 years at
an interest rate of 8%.
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REFERENCES
Brungs, W., 1973. "Effects of Residual
Chlorine on Aquatic Life." Journal of the
Water Pollution Control Federation, Vol.
45, No. 10. pp. 2180-2189.
CXY Chemicals. "Material Safety Data
Sheet." Internet site at
http://www.cxychem.com/whatwedo/chlor
ine/chlorine_safety_sheet.html, accessed
July, 1999.
Hall, Jr., L., et al., 1981. "Comparison of
Ozone and Chlorine Toxicity to the
Development Stages of Striped Bass,
Morone Saxatilis." Canadian Journal of
Fisheries and Aquatic Science, Vol. 38.
Hass, C., K. Longley, and T. Selfridge,
1990. "High-Rate Coliform Disinfection of
Storm Water Overflow." Research Journal
of the Water Pollution Control Federation,
V. 62, No. 3, pp.282-287.
Huang, J.Y.C., R. Warriner, N. Ni, 1985.
"Pilot Tests of Chlorination Facility for
Disinfecting Secondary Effluent." Journal
of the Water Pollution Control Federation,
Vol. 57, No. 7. pp. 784-787.
Rein, D., G. Jamesson, and R. Monteith,
1992. "Toxicity Effects of Alternate
Disinfection Processes." Water
Environment Federation 65th Annual
Conference & Exposition.
Rouge River National Wet Weather
Demonstration Project, 1999. Personal
communication with Parsons Engineering
Science, Inc.
Tift, E., P. Moffa, S. Richardson, and R.
Field, 1977. "Enhancement of High-Rate
Disinfection by Sequential Addition of
Chlorine and Chlorine Dioxide." Journal of
the Water Pollution Control Federation.
9. U.S. EPA, 1973. Microstraining and
Disinfection of Combined Sewer Overflows -
Phase II. EPAR2-73-124.
10. U.S. EPA, 1974. Microstraining and
Disinfection of Combined Sewer Overflows-
Phase III. EPA 670/2-74/049.
11. U.S. EPA, 1975. Bench-Scale High-Rate
Disinfection of Combined Sewer Overflows
with Chlorine and Chlorine Dioxide. EPA
670/2-75-021.
12. U.S. EPA, 1979. Disinfection/Treatment of
Combined Sewer Overflows: Syracuse, New
York. EPA 600/2-79-134.
13. U.S. EPA, 1985. Ambient Water Quality
Criteria for Chlorine-1984.
14. Venosa, A., 1983. Current State-of-the-Art
of Wastewater Disinfection. Journal of the
Water Pollution Control Federation. Vol.
55, No. 5. pp 457-466.
15. Ward, R., and G. DeGraeve, 1978.
"Residual Toxicity of Several Disinfectants in
Domestic Wastewater." Journal of the
Water Pollution Control Federation.
16. Water Environment Research Foundation,
1995. Comparison of UV Irradiation to
Chlorination: Guidance for Achieving
Optimal UV Performance.
17. Water Environment Federation, 1996.
Wastewater Disinfection. Manual of Practice
FD-10.
18. Water Pollution Control Federation, 1989.
Combined Sewer Overflow Pollution
Abatement.
19. White, G., 1992. Handbook of Chlorination
and Alternative Disinfectants. 3rd Ed. New
York: Van Nostrand Reinhold.
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ADDITIONAL INFORMATION
Bay City, Michigan
Michael Kuhn
Superintendent
Bay City Wastewater Plant
2905 Northwater Street
Bay City, MI 48708
Georgia Environmental Protection Agency
James A. Sommerville
Manager, East Compliance Unit
Municipal Permitting Program, Georgia EPA
4244 International Parkway, Suite 110
Atlanta, GA 30354
Oakland County, Michigan
Douglas Bouchholz
Oakland County Drain Commissioner's Office
1 Public Works Drive
Waterford, MI 48328
Trojan Technologies Inc.
David Tomowich
Managing Director
3020 Gore Road
London, Ontario N5 V 4T7 Canada
Wayne County, Michigan
Vyto Kaunelis
Chief Deputy Director
Wayne County Dept. of Environment
415 Clifford Street
Detroit, MI 48226
For more information contact:
Municipal Technology Branch
U.S. EPA
Mail Code 4204
401 M St., S.W.
Washington, D.C., 20460
I
Exceience fh compliance through optftnal technical sotrtroru:
MUNICIPAL TECHNOLOGY
MTB
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