United States
              Environmental Protection
              Agency
            Office of Water
            (WH-595)
September 1991

832S91100
&EPA
Hydrogen Suitide Corrosion:
Its Consequences,
Detection and Control
                                   &*&•;&-..
                                        ••/*f .1

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                   Acknowledgements
 Material in this document was prepared under EPA
,Contract 68-C8-0023 by HydroQual, Inc. and J.M.,
 Smith & Associates, Consulting Engineers. Principal
 authors were Robert P.G. Bowker and Gerald A.
.Audibert of J.M. Smith & Associates. Technical
 review and graphical support was provided by
 Eugene Donovan and the staff at HydroQual, Inc..

 EPA staff who provided technical guidance and
 review include Irene Suzukida, formerly with EPA's
 Office of Water, Office of Wastewater Enforcement
 and Compliance, Lam Lim with the Office of
Wastewater Enforcement and Compliance, and
Randy Revetta with EPA's Center for Environmental
Research Information.

The information in this document is a summary of the
larger, detailed report entitled, " Detection, Control,
and Correction of Hydrogen Sulfide Corrosion in
Existing Wastewater Systems." Mention of trade
names or commercial products does not constitute
endorsement by EPA. Omission of certain products
from  this document does not reflect a position of
EPA regarding product effectiveness or applicability.
           Cover:  Unexpected Street Collapse Due to Sewer Corrosion
                       (photo courtesy of Instituform, Inc.)

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                              Introduction
 Is undetected hydroge.n sulfide corrosion causing
 steady deterioration of your sewerage system? Will
 you be faced with costly sewer replacement or reha-
 bilitation projects in ten or twenty years even though
 the design life of the system may be fifty years or
 more? Unfortunately, many municipalities do  not .
 recognize corrosion problems until extensive damage •
•has occurred, such as a sewer collapse or equipment
 failure. The cost to repair or  replace pipes,
 equipment and structures deteriorated by hydrogen
 sulfide corrosion may exceed by many times the cost
 to control the corrosion and avoid infrastructure
 damage. Nationally, the cost to repair corrosion
 damage by hydrogen sulfide is in the billions of
 dollars, and many communities will spend millions of
 dollars in the next few years to correct corrosion
 problems. Severe corrosion experienced in Los
 Angeles County and municipalities throughout the
 United States prompted Congress to direct the U.S."
. Environmental Protection Agency to conduct a
 national assessment of the problem, resulting in the
 Report to Congress: Hydrogen Sulfide Corrosion in
 Wastemater Collection and Treatment Systems in
 1990.  As a follow-up to that work, 'a technical
 handbook was prepared entitled Detection, Control,
 and Correction of Hydrogen Sulfide Corrosion in
 Existing Wastewater Systems, This brochure
 provides an overview of that document.
 Sewer replacement can be a very costly proposition, especially in urban areas.

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                                      .Chapter?
         What  Are The Implications  Of
         Hydrogen  Sulfide  Corrosion?
•    Consequences of H^S Corrosion

The presence of hydrogen sulfide can lead to rapid
and extensive damage to concrete and metals used in
the construction of wastewater collection and
treatment systems.  Sewers,, pump stations, and
'treatment facilities, including electrical controls,
instrumentation, process equipment, tankage and
ventilation systems can be affected. In the U.S. the
problem'is not limited to warm climates, and it is
rarely brought to the attention of the public until a
catastrophic event occurs, such as a sewer collapse
resulting in street cave-in.  Hydrogen sulfide
corrosion in wastewater systems often results in
costly, premature replacement or rehabilitation of
systems used in the transport and treatment of
wastewater.  Sewers designed to last 50 to, 100 years
have failed due to hydrogen sulfide corrosion in as
little as 10 to 20 years. Electrical and mechanical
equipment with an expected source life of 20 years
has required replacement in as little as five years.  •
•    Social and Economic Costs
        /                  -
The economic implications of hydrogen sulfide
corrosion are staggering. A 1989 study conducted by
the Sanitation Districts of Los Angeles County
estimated that over $-150 million is currently needed
to repair or replace 25 miles of extensively damaged
-sewers.  An additional $35 million may also be
required to repair or replace 16 miles with moderate
corrosion unless it can be controlled. The report
further states that if the additional 500 miles of
sewers were to be  severely damaged by corrosion,
their replacement'cost would be $1 billion.  Similarly,
the City of Houston currently estimates the cost of its
sewer rehabilitation program at $477 million.
Seventy percent of the problem is attributed to
hydrogen sulfide corrosion. On a national, scale,.
sewer rehabilitation alone is estimated to cost $6
billion.  In addition to djrect costs associated with
planned  sewer repairs and replacement, unplanned
replacement costs resulting from sewer collapse and
the increase  in preventative maintenance costs are
similarly very high.  It is clearly evident that a means,
to  detect, control and correct hydrogen sulfide
corrosion in existing wastewater systems is the
preferred alternative to premature replacement of
system components.

Hydrogen sulfide is an odorous, toxic gas. Each year,
deaths result from exposure of workers to hydrogen
sulfide gas in confined spaces. Odor complaints
result from neighbors living near wastewater
handling systems who are exposed to low levels of
the gas.  Although difficult to quantify-, these costs
are substantial.

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                                     Chapter 3
                          What  Causes
         Hydrogen  Sulfide  Corrosion?
 •   Mechanism of Sulfide Corrosion

 Hydrogen sulfide corrosion can occur by two
 mechanisms:  1) acid attack resulting from the
 biological conversion of hydrogen sulfide gas to
 sulfuric acid in the presence of moisture, and 2) direct
 chemical reaction with metals such as copper, iron
.and silver with hydrogen sulfide gas.  The first
 mechanism is the one which is the principal cause of
 internal sewer corrosion, while the second can cause
 premature failure of electrical and instrumentation
 systems,  and mechanical equipment used in the
 transport and treatment of wastewater.

 The principal mechanism by which sulfide generation
 and corrosion occurs in sewers is illustrated in Figure
 1, while Figure 2 depicts the process by which
 hydrogen sulfide corrosion causes sewer failure. >
            SO
Figure!.  Mechanism of Sulfide
Generation and Corrosion in Sewers
 — anaerobic
r    bacteria
                 Anaerobic Slime Layer
                  (typically 1mm thick)
(A) Sulfate is biologicajly reduced to
sulfide in the anaerobic slime layer
  on the submerged pipe wall.
                   Condensate;
              Location of H ^.Oxidizing
                     Bacteria
                                                                  Anaerpbic.Slime Layer
                                                                   (typically 1mm thick)
                                               (B) H2S formed in the wastewater is
                                               released from solution as a gas and
                                                 enters the sewer atmosphere
                                                            H S +2O aerobic
                                                                 2 bacteria
                                                                     Corroded
                                                                   Moist Pipe Surface
                                              (C) H2S is oxidized to sulfuric acid by
                                              aerobic Thiobacillus bacteria living on
                                              moist, non-submerged surfaces. Acid
                                               attacks concrete, causing corrosion

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                          Street
 ' -"• '•'•-'•  • -"-'o O ' Backfill (gravel.soil)
   '
(A) Corrosion reduces structural integrity
            of pipe crown
     .;-.-•.• ^>  o.'^.''-.
                                'Accumulation of
                                    Debris
 (B) Crown collapses and'void forms from
        backfill washing into sewer
(C) Backfill continues to wash into sewer
  eventually leading to sewer blockage -
        and/or street collapse
 B    Factors Affecting Corrosion of
      Sewers


 Four conditions must be-satisfied in order for
 hydrpgen sulfide corrosion to take place in sewers:


      1.  Absence o'r very low levels of dissolved
          oxygen in the wastewater .
      2.  Generation of sulfide in the wastewater
          and release of hydrogen sulfide-gas from
          solution       •            ., •  '
      3.  Presence pf moisture on the material to be
          corroded
      4:  Material which is subject to cofrosion by
          sulfuric acid attack.

 Dissolved oxygen depletion is affected by sewage
 velocity, wastewater characteristics, detention time
,and temperature.  Whe'n the dissolved oxygen is
 depleted, the rate of sulfide generation is controlled
 by the concentration of organic materials, nutrients
 and temperature. The subsequent release of hydrogen
 sulfide gas to the atmosphere of a sewer, wet well or
 other confined space is dependent upon the sewage
 pH, extent of turbulence and wastewater temperature.
 Finally, the rate of corrosion is governed by the
 temperature, the quantity of hydrogen,sulfide
 available to be biologically converted to sulfuric acid,
 and the  material's inherent resistance to acid attack.

• In wastewater treatment plants, damage.can be caused
 by .two  mechanisms:  1) acid attack as  described
 above, and 2) direct attack of metals such as iron and
 copper by hydrogen sulfide.   N
                                                  Figure 2.  Process of Sewer Failure
                                                  Due To Hydrogen Sulfide Corrosion

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                                     Chapter 4
        How  Do I Know If A Corrosion
                       Problem  Exists?
It is essential that corrosion problems be identified
early while the c'orrosion can still be controlled.
Otherwise you may be faced with the high cost of
sewer replacement or rehabilitation, and/or premature
replacement or reconstruction of mechanical
equipment, structures and electrical controls used in
wastewater pumping stations and treatment plants.
Corrosion detection and monitoring can be conducted
economically, and the cost of such programs is only a
small fraction of the cost to repair damage caused by
hydrogen sulfide corrosion. Figure 3 shows a flow
diagram of the basic steps involved in identifying
existing or potential corrosion problems.
•    Identifying Potential Problem Areas

Hydrogen sulfide corrosion can be detected at many
locations in wastewater collection and treatment
systems. Areas where corrosion is likely to be found
include the following:
        Sewers with flat slopes, low wastewater
        velocities, and long detention times
        Manholes and junction chambers'
        Force main discharges
        Areas of high turbulence
        Pump station wet wells .
        Treatment facility headworks
        Primary clarifier effluent channels
        Sludge handling structures and equipment
        Heating, ventilating, electrical and
        instrumentation systems
Hydrogen Sulfide Corrosion Can Significantly Reduce the Useful Life of Sewers.

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Figure 3.  Approach to Identifying Existing and Potential Corrosion Problems
                           REVIEW EXISTING INFORMATION
                              TO IDENTIFY POTENTIAL;
                                  PROBLEM AREAS

                                  - Sewer maps
                                  - Locations of pipe
                                    replacement/rehab
                                  -, Odo/complaints
                                  - TV inspection logs
                         CONDUCT PRELIMINARY INSPECTION
                           AT POTENTIAL PROBLEM AREAS
                                                        _••
                                    Visual inspection
                                  -  Atmospheric K^S,,
                                  -  Wastewater DO/sulfide
                                  - - ' 'pH of pipe crowns,
                                     channels, tank walls
                          MEASURE CORROSION AT KNOWN
                                '  PROBLEM AREAS  ,  '  .
                                              A-
                                '  - Manual measurement
                                  - Gore sampling
                                  - Sonic caliper inspection
                          ESTIMATE CORROSION RATES AND
                           PRIORITIZE AREAS FOR FURTHER
                          MONITORING AND/OR CORRECTION

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 Hydrogen Sulfide Corrosion Can
 Cause Premature Failure  of
 Electrical Systems Used in Pump
 Stations and Treatment Plants.
 Sewer maps should be gathered, updated and
 reviewed along with any. odor complaint logs,
 videotapes of sewers, maintenance-records and any
 other information sources that are available.
 Locations of potential corrosion problems, such as
 discharges of force mains, areas of odor complaints,
 pump stations, and plant headworks should be
' highlighted on a sewer map for further investigation.
 Figure 4 shows a typical sewer map with potential
 trouble spots targeted for inspection.
•    Conducting Inspections

A visual inspection should be conducted wherever
possible. If entry into a manhole or confined space is
required, precautionary measures as directed by
OSHA and NIOSH should be carefully followed. A
low-power scope used in conjunction with a mirror
and a light source mounted at the end of a long rod
can be used to inspect sewers without entry.

Measuring pH of pipe crowns, and walls of man-
holes, junction chambers and other confined spaces is
probably the best early warning that a potential or
existing corrosion problem exists. Color-sensitive
pH paper can he used to determine the concrete
surface pH. New pipe has a pH of about 10 but under
corro,sive conditions, pH may be 2 or lower.
Generally, pH values below 4 are indicative of
corrosion problems.

Atmospheric H^S is also a useful indicator of
potential corrosion probleins. Dissolved sulfide
concentrations in the wastewater should also be
measured.  The conditions of the sewer or structure,
as well as other data collected, should be entered on
an  inspection checklist.

•    Measuring and Predicting Corrosion

Several techniques are available to measure the extent
of corrosion. A simple but often inaccurate method is
to  remove the corrosioji product down to sound
concrete and  measure the depth of penetration.
Extendable rods are also used to measure the inside
diameter of the sewer. Coring of pipe crowns at cor-
roded and uncorroded reaches provides good
documentation of corrosion severity, and can be used
to estimate depth of corrosion penetration and the
thickness of remaining concrete over reinforcing
steel. •

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   Figure 4. Sewer Map Showing Locations of Potential Corrosion Problems
   PS
                                                                             i "- "Potential
                                                                              '"'   Problem Areas
A remote method of measuring corrosion is the sonic
caliper.  Sonic caliper technology is a relatively new
development whereby sonic signals determine the
distance from the transmitter to the target (e:g. crown,
waterline, invert).  Television inspection  cannot be
used to measure corrosion, but it can provide a
relative indicator of the severity of corrosion to-the
trained, observer.

Predictive models exist to allow estimates  of the rate
of hydrogen sulfide generation and corrosion, and the
anticipated service life of a sewer or structure. These
empirical equations are presented in publications by,
the U.S. Environmental Protection Agency, the
American Society of Civil Engineers and  the Amer-
ican Concrete Pipe Association. As with all
predictive models, actual data should be collected to
confirm and calibrate the predictive equations.
•     Prioritizing Problem Areas

Rates of corrosion can be estimated based on physical
measurements br predictive models.  Where data are
available on depth of corrosion penetration, average
corrosion rate can be calculated by dividing corrosion
depth by the age of the pipe or structure. The
remaining useful  lifetime of the pipe can then be
estimated based on, for example, corrosion reaching
reinforcing steel. This information serves as a basis
for prioritizing areas for corrective action.  For
example, if severe damage has already occurred,
replacement or rehabilitation may be necessary. If
damage is not extensive but the service life has been
significantly reduced, implementation of a corrosion
control program may be warranted.

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                                         Chapter 5
          How  Do  I  Control  Corrosion?
There are- several methods available to control the
rate of hydrogen sulfide. corrosion. These include 1)
reducing the dissolved sulfide content of the
wastewater, 2) using corrosion-resistant materials and
coatings, 3) providing ventilation of the enclosed area
or sewer, and 4) conducting routine preventative
maintenance. These techniques are discussed below
and presented in Table I.-  •

•     Dissolved Sulfide Reduction
                          1.   Oxidation by addition of chemical
                              oxidants such as hydrogen peroxide,
                             'chlorine or potassium permanganate, or
                              by the introduction of air or, oxygen.
                          2.'  Precipitation of dissolved sulfide by the
                              addition of metallic salts such as ferrous
                              chloride and ferrous sulfate.
Atmospheric hydrogen sulfide levels can be reduced
by controlling the amount of dissolved sulfide
available in the wastewater. Three basic techniques
are used to achieve this goal.
                          3.   pH elevation through the addition of
                           ,   sodium hydroxide (caustic soda).
                       Table 1,  Sumniaty of Corrosion Control Methods
    CLASSIFICATION,

   1. Dissolved sulfide redaction
         Oxidation  ..    ,  „
         Precipitatiott'
         pS Elevation

   2, Corrosion-resistant
   "  materials and coatings
   3. Ventilation
   4, Maintenance
     METHOD
    ygen, air, hydrogen peroxide,  Chemical or biochemical oxidation of,
Chlorine or potassium permanganate ^sulfide       .. ", ,   ,     -'"'"•. /J>,
 addition        ,  ' '   -    , ,     ,   ••'"',-'   ,:    --"''" "'„;   ,;-'
            *       ^        ; 4.  v. "••"-.     ^          ' f             v
,Iron salt addition         'H  "  ,  , , Chemically binds sulfide ta form
                   -'   "••    '^'-insoluble precipitate
 Slug doses of sodium hydroxide       Inactivates sulfate-reducing bacteria

 Use <>f corrosion resistant metals.  Material is resistant to acid attack;
 plastics, concrete* application of  and/or provides Effective barrier
 corrosion resistant paints or coatings  against H^S or iacid migration  ^

 Mechanical ^ventilation of enclosed  Redwces atmospheric H^S levels and
 spaces; purging with clean air or  surface moisture         ,
 nitrogen                      '!  '?,,  ',*•"••  ~    '   -'  ,   , -,-

 Sewer cleaning by flushing or  Minimizes accumulation of debris that
 pigging                /       "• 'c^h. refute velocities, increase organic-
                      >       '-'•. * matter deposition and increase sulfide
 " ,  -    ' *                 " , ,''".. generafiou ^           ,  '  ,
     ^            ^/      ^         "   •"  •.  f.  ff             \  f St ff
f      -f       '   "   '' V v ~-   * \ v"1 •*' •* f      s           *•     "" '      **

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 The basic goals and treatment levels for the three
 basic techniques must be developed individually for
 each system, but generally the goals strive to meet the
 following guidelines:

       1.  Maintain dissolved oxygen greater than
 •  . '      0.5 mg/1.     "                        •
       1.  Keep dissolved, sulfide levels below 0.3
          mg/1.                    \
       3.  Maintain atmospheric hydrogen sulfide
          levels below 5 pp'm.
       4.  Increase concrete pH to 4 or greater.

 •     Corrosion-Resistant Materials and
       Coatings

 Another method used to prevent corrosion or control
 the rate of corrosion is'to utilize corrosion-resistant
 materials, both in the collection system and at the
 wastewater treatment plant.  Corrosion-resistant
- materials fall under the following categories: 1)
 metallic coatings, 2) metal alloys,  3)  corrosion-
 resistant concrete, and 4) plastics.

 Metallic coatings include galvanizing and electro-
 plating systems.  Metal alloys include copper,
 aluminum, nickel; and stainless steel.

 The corrosion resistance of concrete can be improved
 by two ways: 1) use of high alumina or high-silica
 cement, or, 2)  use of calcareous (e,g. limestone)
 aggregate. The use of such concrete  in low-pH
 environments may still lead to concrete degradation
 but at a somewhat lower rate.  In cases where
 corrosive conditions are anticipated, concrete pipe
 can be manufactured with a cast-in-place PVC liner.

 The use of polyvinyl chloride, polyethylene,
 fiberglass reinforced polyesters and other plastics are
 becoming more commonplace in,the wastewater
 field.  Many of these matefiajs offer excellent
 corrosion' resistance.

 Certain paints and protective coatings can provide
 some degree of corrosion resistance.  Paints and
 protective coatings include vinyl, epoxy and silicone
 resin primers and paints. Paints can be classified as
 either thermoplastic, which is applied hot and cured
 by cooling, or thermosettihg, which cures by
 chemical reaction with a setting agent. Thermo-
 plastic paints include asphaltic/coal  tar and
 polyethylene; thermosetting, paints include
 polyurethane and epoxy.  The proper preparation,
 application and-curing procedures  must be closely
 followed for any coating system to be successful.
 Even adherence to proper procedures may not result
 in adequate coating performance in corrosive
 environments,, as the success of such coatings has.
 been highly variable.

 •    Ventilation

 Ventilation of sewers and enclosed spaces  can
 potentially'reduce hydrogen sulfide corrosion by
 reducing the concentration of hydrogen sulfide in the
 atmosphere, and by drying the walls of the pipe or
 structure. Ventilation of sewers apparently had some
 success for corrosion control in Austin, Texas,  Los
 Angeles, California and Sydney, Australia.  Air
 discharged from a sewer would normally require
 treatment to control odors. There is some  question
 regarding the effectiveness and  practicality of
 controlling corrosion by this technique.

 Ventilation with clean air can be  used to control
 corrosion in electrical cabinets or rooms  housing
 sensitive electronic equipment. Electrical  cabinets
 can be purged with  nitrogen to provide excellent
 corrosion protection.

 •    Maintenance

 Routine sewer cleaning can be an effective deterrent
 to the hydrogen sulfide corrosion process. This is
 because accumulations of debris tend to reduce the
 wastewater velocity  and thus increase its detention
 time within the sewer,  allowing it to  be.come
 anaerobic.  As the wastewater velocity decreases,
 further deposition of organic matter occurs, which
 results in increased biological activity, depletion of
 oxygen, and generation of,sulfide. Deposition of
 solids is likely due to excessively flat  sewer grades
 combined with low flows - these  areas should be
' monitored for solids accumulation.  Gravity sewers
 should be routinely flushed or pressure-washed; force
 mains may require pigging.

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                                 Chapter 6
             What Options  Do  I  Have
  To  Rehabilitate Corroded  Sewers?
•   Methods Available

Various methods are available for rehabilitating
corroded sewers, and these methods continue to be
improved. The basic categories are as follows:
       Excayation and replacement
       Cured-in-place inversion lining
       Insertion renewal
       Liners            .
       Specialty concrete
Excavation and replacement is usually the most
costly and most disruptive means by which to correct
sewer deficiencies. The same problem will likely
redevelop however, if a similar honcorrosion-resistant
material is used in the replacement without other
corrective measures taken to decrease the severity of
the corrosion problem.  '      •       -  •

Trenchless.technology is presenting new methods to
protect against corrosion. One such method is the use
of cured-in-place inversion linings, whereby a
flexible "sock" is inserted into the pipeline, set in
place by the  addition of water, and cured in place.
Rehabilitation Using Cured-in-Place Inversion Lining Can Be An Economical
Alternative To Replacement of Severely Corroded Sewers (photo courtesy of
Insituform, Inc.)

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Insertion renewal consists of jacking a pre-formed
pipe through the.existing sewer.  Some methods
involve the use of an insertion pipe of slightly smaller
diameter than the existing sewer, while others involve
the use of a,tool which first breaks away the existing
sewer and is followed immediately by the new pipe.
Ah alternate method of insertion renewal involves the
use,of a deformed pipe which is inserted and then
expanded to its final shape.
Insertion of a corrosion-resistant liner made of fiberglass, PVC, or polyethylene
is an effective means of sewer rehabilitation (photo courtesy of Price Bros., Inc.).

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Liners can be used on larger-diameter sewers.
Prefabricated PE or PVC panels are installed onto the
existing pipe substrate, forming a continuous inter-
locking strip.               , ' '  •

Specialty concrete consists of different cements
and/or aggregates which are more resistant to
            hydrogen sulfide corrosion than Portland cement
            concrete. These concretes may still be susceptible to
            corrosion, though at a reduced rate.
            Table 2 summarizes the principal methods of pipeline
            rehabilitation.
              Table 2,  Principal Methods fa* Pipeline Rehabilitation
             METHOD
     Insertion Renewal (Sliplining)

     Deformed Pipe Insertion


     Cured-in»PIaee Inversion Lining
            ._                 \   J


     Specialty Concrete (Spot repair)


     Coatings      ,  -



     Liners•
      Pipe Replacement
         ?.•
     ,Exterior Wrap and Cap
                 APPLICATION
      Used for cracked or deteriorated sewer pipes*
                           '"
      Similar applications as for sliplinirig but for
' ^ "', ..relatively small (<24) circular pipe*

      Sewer pipe of any geometry^ largest current
      application is for 96 inch diaineter pipe,

      Large sewers or manholes needing structural
    , repairs.      "  ,  ' - '

      Rapidly growingjaiethod for pipes and man-
      holes with new application methods being
      marketed continually; variable effecftvness.  ;__
            f    i
      Should Be used oiily iiistructurafly sound
      sewers. Can easily fit variations in grades*
      slopes; cross-section for manually applied strip
      applications.                  ~
•.                         ..        ••     t  s    •"  '
      Any pipe with major structural defects,.

      Provides back-up corrosion protection and
      structurally reinforces existing pipeline.  Simi-
.  . - ,  lar method applicable to monolithic structures.
•     Selecting a Rehabilitation Technique

The rehabilitation method to be used in pipeline
repair is dependent upon the actual cpndition of the
existing,sewer, its location, number of service
connections, surface cover and intended service life.
These factors also directly impact the cost to perform
the'work.     "                  .
            In cases where the wastewater flow within the
            existing pipe cannot be diverted, sliplining may be
            the only practical approach short of constructing a
            new sewer. In most situations however, both tangible
            and intangible factors will enter into the decision-
            making process.

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                                    Chapter 7
                         Conclusions
Hydrogen* sulfide corrosion is .suspected to
occur in over 50% of all wastewater collection
and  treatment facilities, regardless of
geographic location, age or size. In some
cases,  the first sign of hydrogen sulfide,
corrosion problems is a sewer collapse or other
catastrophic failure.

On a national scale, the cost to correct existing
corrosion problems is estimated to be in the
billions of dollars.  Many communities will
need to spend millions of dollars in the near
future to address the consequences of hydrogen
sulfide corrosion.
Establishing a corrosion monitoring plan and
conducting corrosion inspections as part of
routine operation and maintenance will provide
valuable information on the conditions of
existing systems, shed insight into the causes
of hydrogen sulfide corrosion problems, and
allow selection of cost-effective approaches to
control corrosion.

The end result will be collection systems and
treatment facilities that last longer and operate
more efficiently.

The  cost  of monitoring and control  of
corrosion will be easily offset by the savings
accrued by avoiding premature replacement or
rehabilitation.

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                                   Chapter 8
   Sources of  Additional  Information
Several recent publications are available from EPA
that address the problems of hydrogen sulfide
corrosion, procedures for detecting and controlling
corrosion, and methods for rehabilitating corroded
sewers and structures. These include

     1)   Hydrogen Sulfide Corrosion in
         Wastewater Collection and Treatment
         Systems, Report to Congress;      '

     2)   Detection, Control, and Correction of
         Hydrogen Sulfide Corrosion in
         Existing Wastewater Systems; and
    3)   Handbook  - Sewer  System
         Infrastructure Analysis and
         Rehabilitation.

These and other relevant publications are listed in
Appendix A. Questions regarding, the EPA
publications listed above may be directred to the EPA
Office of Wastewater Enforcement and Compliance,-
Municipal Technology Branch at (202) 260-7356, or
to one of the EPA Regional Offices shown in
Appendix B.

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                             ! APPEND IX A
                        References
Morton, R., R. Caballero, Ching-Lin Chen      7.
and J. Redner, Study of Sulfide Generation
and Concrete Corrosion of Sanitary Sewers.
In-house report; Sanitation Districts of Los
Angeles County, Whittier, CA, 1989.   '    '--  -/

National Sewer Rehab Projected at $6
Billion, Civil Engineering, pp. 20-24, July,      8..
1991.
A Guide to Safety in Confined Spaces,
National Institute for Occupational Safety
and  Health (NIOSH), No.   87-113,.
Morgantown, WV.
Bowker, R.P.G., J.M. Smith, and N.A.
Webster, Odor and Corrosion Control in
Sanitary Sewerage Systems and Treatment
Plants, Design Manual, U.S. Environmental       10.
Agency, Center for Environmental Research,
Cincinnati, OH, 1985.                           .

Sulfide in  Wastewater Collection and
Treatment Systems, ASCE Manual No. 69,
American Society of Civil Engineers, New       11.
York, NY, 1989.

Sulfide and Corrosion Prediction and
Control,  American Concrete Pipe
Association, Vienna, VA, 1984
 Redner, J.A., R.P. Hsi, and E.J. Esfandi,
 Progress Report - Evaluation of Protective
 Coatings for Concrete, paper presented at
 EPA Technology Transfer Seminar on Sewer
 System Infrastructure Analysis  and
 Rehabilitation, 1991.

 Sulfide Corrosion in Wastewater Collection
 and Treatment Systems, Report to Congress,
 U.S. Environmental Protection Agency,
 Office of Water,' Washington, DC, 1991.

 Hydrogen Sulfide Corrosion in Wastewater
 Collection and Treatment Systems, Report
 to Congress - Technical Report, U.S.
 Environmental Protection Agency, Office of
 Water, Washington, DC, 1991.
  •/*'                   f
 Detection,  Control and Correction of
 Hydrogen Sulfide Corrosion in Existing
 Wastewater Systems, U.S. Environmental
 Protection Agency, Office of Water,
, Washington, DC, 1991.

 Handbook -Sewer System Infrastructure
 Analysis and Rehabilitation, EPA-625/6-
 91/030, U.S. Environmental Protection
 Agency, Center  for Environmental Research
 Information, Cincinnati, OH, 1991.

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                                        APPENDIX B
                    EPA  Regional  Offices
U.S. EPA Region 1
John F. Kennedy Federal Building
Room 2203
Boston, MA 02203
(617) 565:3715
U.S. EPA Region 2
26 Federal Plaza Room 900
New York, NY 10278
(212) 264-2657

U.S. EPA Region 3
841 Chestnut Street
Philadelphia, PA 19107
(215) 597-9800
U.S. EPA Region 4
345 Courtland Street NE
Atlanta, GA 30365
(404)347-4727
U.S. EPA Region 5
230 South Dearborn Street
Chicago, IL 60604
(312)353-2000  ,
Connecticut
Maine
Massachusetts •
New Hampshire'
Rhode Island
Vermont

New Jersey
New York
Puerto Rico
•Virgin Island

Delaware
District of Columbia
Maryland
Pennsylvania
West Virginia
Virginia

Alabama
Florida j
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee

Illinois
Indiana
Michigan
Minnesota   , \
Ohio
Wisconsin
U.S. EPA Region 6              Arkansas
1201 Elm. Street                 Louisiana
Dallas, TX 75270                New Mexico
(214) 655-6444                  Oklahoma
                              Texas

U.S. EPA Region 7              Iowa
726 Minnesota Avenue '           Kansas
Kansas City, KS 77101            Missouri
(913) 236-2800               ,   Nebraska

U.S. EPA Region 8         '     Colorado
One Denver Place - Suite 1300      Montana
999 l'8th Street               .   North Dakota
Denver, CO 80202-2413           South Dakota
(303) 293-1603          **       Utah
                         1 •    Wyoming

U.S. EPA Region 9   :           Arizona
75 Hawthorne Street          v    California
San Francisco, CA 94105          Hawaii
(415) 744-1305         ,         Nevada

U.S. EPA Region 10             Alaska
1200 Sixth Avenue               Idaho
Seattle, Washington 98101         Washington
(206)442-5810    .      ~       Oregon

NOTE: The telephone numbers listed are general information
numbers only; please ask for the program office to obtain
specific information on the issues discussed in this booklet.  •

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