QUESTION:
1) Most importantly, what differences might we expect in lime-treating
raw sewage as opposed to sludge, which most of the literature
describes?
ANSWER:
There is no effective difference in treatment methods or results.
From:
Process Design Manual
Land Application of Sewage Sludge and Domestic Septage
EPA/625/K-95/001
http://www.epa.gov/ORD/WebPubs/landapp.pdf
Chapter 11
Land Application of Domestic Septage
"The Part 503 regulation governing the use or disposal of sewage
sludge, promulgated in February 1993, includes simplified requirements
for the land application of domestic septage
(compared to more extensive requirements for other types of sewage
sludge generated by a wastewater treatment plant). While the Part 503
rule provides minimum guidelines for state programs, individual state
regulations may be more stringent."
[...]
"Domestic septage is defined in the Part 503 regulation as the liquid
or solid material removed from a septic tank, cesspool, portable
toilet, Type III marine sanitation
device, or a similar system that receives only domestic sewage (water
and wastewater from humans or house-hold operations that is discharged
to or otherwise enters
a treatment works). Domestic sewage generally includes wastes derived
from the toilet, bath and shower, sink, garbage disposal, dishwasher,
and washing ma-chine. Domestic septage may include household septage
as well as septage from establishments such as schools, restaurants,
and motels, as long as this septage does not contain other types of
wastes than those listed above."
QUESTION:
2) Assuming liquid (urine) and solid wastes will be treated with lime,
should we be concerned about ammonia off-gassing from reaction with
urine?
ANSWER:
Out-gassing is a normal byproduct of the reaction of the lime and
Nitrogen in the wastes, solid or liquid. However, a latrine system
with urine diversion can be installed to separate urine from the solid
waste. Urine needs little processing. See the Ecological Sanitation
links below.
AMMONIA OUT-GASSING
From:
Stabilization of Sewage Sludges (Bio-Solids)
http://www.e-limecementgypsum.com/papers/papers_scheda.asp?ID=39
"3. Ammonia conversion and gas release: In sludges containing
nitrogen, ammonia gas will be released when the pH rises above about
9, with almost complete conversion and release by pH 10. The pH
reading of ammonia as it is "gassing off" may exceed 12, leading an
uninformed operator to believe that sufficient lime has been added to
meet regulatory requirements. But, as soon as the ammonia conversion
is completed, the pH of the sludge mass will be at about 10 - not
meeting regulatory requirements. At pH 10, bacteria may recontaminate
this clean unstabilized organic matter, resulting in regrowth and
offensive odors. Measuring the pH of the fully mixed sewage mass,
after ammonia has gassed off, assures that sufficient lime based
alkaline material has been added in order to achieve the regulatory pH
of "12 or above", assuring stabilization and that regrowth will not
occur. Ammonia gas should be captured by scrubbing the mixer vent
with weak sulphuric acid solution, capturing the resulting liquid. The
resulting ammonium sulfate is a valuable liquid fertilizer; a
potential economic benefit of the lime stabilization processes."
QUESTION:
3) What would be some good upper/lower estimates of addition rates
(mass per mass sewage) of lime to raw sewage to achieve pH >12?
ANSWER:
Approximately 20 to 25 pounds of lime are used for every 1,000 gallons
of septage. (See Alkali Stabilization below.)
QUESTION:
4) How about to achieve temp > 65C?
ANSWER:
As far as I can tell, your points 3 and 4 are actually alternative
methods of treating septage. While the addition of lime does release
heat, the purpose of lime is to raise the alkalinity level not to
generate heat. Indeed, the EPA guidelines suggest that 25 deg. C is
the optimum temperature at which pH measurements are to be made or to
which they are adjusted. Temperature processing of waste, on the other
hand, is used instead of or in addition to lime stabilization and is
accomplished typically through composting. Compare 1 and 4 below.
From:
Stabilization of Sewage Sludges (Bio-Solids) (IBID)
"1. The proper reading of pH. Many plant operators, process owners,
regulatory personnel and others do not fully understand how to
standardize a pH meter to insure that the reading one gets from the
meter has validity. To get a proper pH reading at this high end of the
pH scale, the reading must be taken at the standard temperature- 25
[degrees] C, or corrected to 25 [degrees] C, using the formula
published by EPA. The sample and the fresh standard solution used for
calibration of the meter must both be at 25 [degrees] C in order to
obtain a correct reading. This is covered in SW-846, EPA Laboratory
Procedures and Test Methods, under Methods 9040B, and 9045C, revisions
published in the Federal Register April 4, 1995.(pg 17003, FR 60, vol
64, Tues., April 4, 1995). A guide published by National Lime
Association that may be helpful in clarifying this pH /temperature
relationship is available from the Association at 703-243-5463.
If one reads the pH of a solution at other than standard temperature,
then the pH meter reading will either be too high, or too low,
depending on the temperature of the test sample, leading to an
incorrect assumption that stabilization levels have been
achieved."
Adapted from:
Table 11-4. Summary of Domestic Septage Stabilization Options (U.S.
EPA, 1994b)
Process Design Manual
Land Application of Sewage Sludge and Domestic Septage
EPA/625/K-95/001 (IBID)
"Method Description
1) Alkali sltabilization a Lime or other alkaline material is added to
liquid domestic septage to raise pH to 12.0 for minimum of 30 min.
Advantages
Very simple; minimal operator attention. Low capital and O&M costs.
Provides temporary reduction in sulfide odors. Meets EPA criteria for
reduction in vector attraction. Reduces EPA site restriction
requirements for land application.
Disadvantages
Increases mass of solids requiring disposal. Handling of lime may
cause dust problems. Lime feed and mixing equipment require regular
maintenance.
2) Aerobic digestion Domestic septage is aerated for 15 d to 20 d in
an open tank to achieve biological reduction in organic solids and
odor potential. (Time requirements increase with lower temperatures.)
Advantages
Relatively simple. Can provide reduction in odors.
Disadvantages
High power cost to operate aeration system. Large tanks or basins
required. Cold temperatures require much longer digestion periods.
3) Anaerobic digestion Domestic septage is retained for 15 d to 30 d
in an enclosed vessel to achieve biological reduction in organic
solids.
Advantages
Generates methane gas, which can be used for digester heating or other
purposes.
Disadvantages
Requires skilled operator to maintain process control High maintenance
requirements for gas handling equipment. High capital costs. Generally
not used except for co-treatment with sewage sludge.
4) Composting Liquid domestic septage or domestic septage solids are
mixed with bulking agent (e.g., wood chips, sawdust) and aerated
mechanically or by turning. Biological activity generates temperatures
sufficiently high to destroy pathogens.
Advantages
Final product is potentially marketable and attractive to users as
soil amendment.
Disadvantages
Costly materials handling requirement. Requires skilled operator
process control. High odor potential. High operating costs.
a Only alkali stabilization meets Part 503 domestic septage treatment
requirements."
ALKALI STABILIZATION
Decentralized Systems Technology Fact Sheet Septage Treatment/Disposal
EPA 832-F-99-068
http://www.epa.gov/owmitnet/mtb/septage.pdf
"Alkali (Lime) Stabilization
Lime or other alkaline material is added to liquid septage to raise
the pH to 12.0 for a minimum of 30 minutes. Although there is a lot of
variation in septage characteristics and lime requirements, mixing is
not very difficult, and approximately 20 to 25 pounds of lime are used
for every 1,000 gallons of septage. The three main stabilization
approaches before land application are to add lime slurry: 1) to the
pumper truck before the septage is pumped, 2) to the pumper truck
while the septage is being pumped, or 3) to a tank that is storing
septage that was discharged from a pumper truck. The septage and lime
may sometimes be mixed by a coarse bubble diffuser system located in
the tank or truck. In some states, it is prohibited to use hauler
trucks for the stabilization process. A separate storage tank is
necessary for lime and septage mixing. This is beneficial because a
separate holding tank allows for more uniform mixing and easier
sampling, monitoring, and control."
From:
Process Design Manual
Land Application of Sewage Sludge and Domestic Septage
EPA/625/K-95/001 (IBID)
"11.3 Adjusting the pH of Domestic Septage
The Part 503 regulation regarding land application of domestic septage
is less burdensome if alkali stabilization is practiced. Stabilization
is a treatment method designed to reduce levels of pathogenic
organisms, lower the potential for putrefaction, and reduce odors.
Stabilization methods for domestic septage are summarized in Table
11-4 (U.S. EPA, 1994a). The simplest and most economical technique for
stabilization of domestic septage is pH adjustment. Usually, lime is
added to liquid domestic septage in quantities sufficient to increase
the pH of the septage to at least 12.0 for 30 minutes (U.S. EPA,
1994b). If the lime is added before or during pumping of the septic
tank, in many cases 30 minutes will elapse before the truck reaches
the land application site. Other stabilization options, such as
aerobic digestion, are relatively simple but have higher capital and
operating costs (U.S. EPA, 1994b), and cannot be used to meet Part 503
domestic septage treatment requirements (for application to
agricultural land, forests, or reclamation sites). To raise the pH of
domestic septage to 12 for 30 minutes, sufficient alkali (e.g., at a
rate of 20 lb to 25 lb of lime [as CaO or quicklime] per 1,000 gal
[2.4 kg to 3.6 kg per 1,000 L]) of domestic septage typically is
needed, although septage characteristics and lime requirements vary
widely (U.S. EPA, 1994b). EPA recommends the following approaches for
alkali stabilization prior to land application (U.S. EPA, 1994b):
* Addition of alkali slurry to the hauler’s truck before the domestic
septage is pumped into the truck, with additional alkali added as
necessary after pumping.
* Addition of alkali slurry to the domestic septage as it is pumped
from the septic tank into the hauler’s truck. (Addition of dry alkali
to a truck during pumping with a vacuum pump system is not
recommended; dry alkali will be pulled through the liquid and into the
vacuum pump, causing damage to the pump.)
* Addition of either alkali slurry or dry alkali to a holding tank
containing domestic septage that has been discharged from a pumper
truck.
Many states allow domestic septage to be alkali-stabilized within the
truck. Some states, however, prohibit alkali stabilization in the
hauler’s truck and require a separate holding/mixing tank where alkali
addition and pH can be easily monitored. A separate holding and mixing
tank is preferred for alkali stabilization for the following reasons
(U.S. EPA, 1994b):
* More rapid and uniform mixing can be achieved.
* A separate holding and mixing tank affords more control over
conditions for handling and metering the proper quantity of alkali.
* Monitoring of pH is easier, and more representative samples are
likely to be collected due to better mixing.
* Raw domestic septage can be visually inspected. To prevent damage to
vacuum pumps and promote better mixing of the alkali and domestic
septage, alkali should be added as a slurry (U.S. EPA, 1994b). The
slurry can be added to the truck before pumping the tank, although the
amount of alkali necessary to reach pH 12 will vary from load to load.
Provisions should be made to carry additional alkali slurry on board
the truck to achieve the necessary dosage (U.S. EPA, 1994b).
Compressed air injection through a coarse-bubble diffuser system is
the recommended system for mixing the contents of a domestic septage
holding tank. Mechanical mixers are not recommended because they often
become fouled with rags and other debris present in the septage (U.S.
EPA, 1994b).
Figure 11-6 presents a procedure for alkali-stabilizing septage within
the pumper truck. Methods recommended by domestic septage servicing
professionals are presented in Domestic Septage Regulatory Guidance
(U.S. EPA, 1993), along with associated cautions. If pH adjustment is
used for domestic septage, the Part 503 requirements apply to each
truckload unless pH adjustment was done in a separate treatment device
(e.g., lagoon or tank) (U.S. EPA, 1993)."
[...]
Purpose To raise the pH of domestic septage to 12 for a minimum of 30
min.
Approach
* Add lime slurry in sufficient quantity before pumping the tanks and
add additional slurry as needed after pumping.
* Add lime slurry in sufficient quantity during pumping of the tanks
by vacuuming slurry through small suction line fitted to main suction
hose.
Type of lime
* Pulverized quicklime (CaO).
* Hydrated lime (Ca(OH)2).
(Less quicklime is required than is hydrated lime to achieve the same
pH, but quicklime is more corrosive and difficult to handle.) Dosage
Typically 20 lb to 25 lb quicklime per 1,000 gal of domestic septage
(or about 26 lb to 33 lb of hydrated lime per 1,000 gal). Slurry
Approximately 80 lb of pulverized quicklime or hydrated lime in 50 gal
of water. Mix mannually with paddle in a 55-gal drum or in a 200-gal
polyethylene tank with electric mixer (preferred). CAUTION: Heat is
liberated when quicklime is added to water. Wear rubber gloves,
appropriate respirator (for dust), and goggles. Add lime slowly to
partially full tank. an emergency eyewash station should be located
nearby.
Application rate
Typically 12 to 15 gal quicklime slurry per 1,000 gal of domestic
septage (or 15 gal to 20 gal hydrated lime slurry). Monitoring After
lime slurry has been mixed with domestic septage, collect sample from
top access hatch using a polyethylene container fastened to a pole.
Measure pH with pH meter at 25°C (or convert reading to 25°C). (pH
paper can also be used, but it is more cumbersome and less accurate.)
If the pH is less than 12, add more slurry. If pH 12 has been reached,
record pH and time. Sample again after 15 min. If the pH has dropped
below 12, add more lime. The pH must remain at 12 for at least 30 min.
Sample and record pH prior to applying septage to the land. Figure
11-6. Procedure for lime-stabilizing domestic septage within the
pumper truck (U.S. EPA, 1994b).
QUESTION:
5) What is the most appropriate method for measuring the pH of raw
sewage? EPA 9040A, B or C?
ANSWER:
pH TESTING METHODS APPROVED BY EPA
Stabilization of Sewage Sludges (Bio-Solids) (IBID)
"This is covered in SW-846, EPA Laboratory Procedures and Test
Methods, under Methods 9040B, and 9045C, revisions published in the
Federal Register April 4, 1995.(pg 17003, FR 60, vol 64, Tues., April
4, 1995)."
EPA TESTING METHODS from EPA Web site
pH - Continuous Monitoring (Electrometric) 0150.2 600/4-79-020
pH - Electrometric 0150.1 600/4-79-020
pH - Electrometric Measurement 9040B SW-846 Ch 8.2
pH - Paper Method 9041A SW-846 Ch 6
pH Adjustment (6.10) TIE-CHR 600/6-91-005F
pH Adjustment Test, Acute Effluent (8.3) TIE-ACUT 600/6-91-003
pH Adjustment/C18 Solid Phase Extraction (8.6) TIE-ACUT 600/6-91-003
pH Adjustment/Filtration Test (8.4) TIE-ACUT 600/6-91-003
pH Adjustment/Filtration Test, (8.5) TIE-ACUT 600/6-91-003
pH of Wet Deposition -Electrolytic Determination 0150.6 600/4-86-024
From:
Process Design Manual
Land Application of Sewage Sludge and Domestic Septage
EPA/625/K-95/001 (IBID)
"11.3.1 Sampling for pH
Land appliers of domestic septage should not automatically assume that
the lime or other alkali material added to domestic septage and the
method of mixing chosen will adequately increase pH. The pH must be
tested. A representative sample should be taken from the body of the
truckload or tank of domestic septage for testing. For example, a
sampling container could be attached to a rod or board and dipped into
the domestic septage through the hatch on top of the truck or tank or
through a sampling port (U.S. EPA, 1993). Alternatively, a sample
could be taken from the rear discharge valve at the bottom of the
truck’s tank. If the lime has settled to the bottom of the tank,
however, and has not been properly mixed with the domestic septage,
the sample will not be representative. Two separate samples should be
taken 30 minutes apart, and both of the samples must test at pH 12 or
greater (with the pH reading converted to an equivalent value at 25°C
to account for the influence of hot and cold weather on meter
readings). If the pH is not at 12 or greater for a full 30 minutes,
additional alkali can be added and mixed with the domestic septage.
After mixing in the additional alkali, however, the domestic septage
must be at 12 or greater for a full 30 minutes to meet the pH
requirement of the Part 503 regulation (U.S. EPA, 1993)."
and,
TNRCC REGULATORY GUIDANCE
Registration & Evaluation Division
RG-371
April 2000
SUBJECT: Disposal of Domestic Septage
http://www.tnrcc.state.tx.us/admin/topdoc/rg/371.pdf
See also:
Code of Federal Regulations
40 CFR - CHAPTER I - PART 503
§ 503.8 Sampling and analysis.
http://ecfr1.access.gpo.gov/otcgi/cfr/otfilter.cgi?DB=1&ACTION=View&QUERY=503.8&RGN=BSEC&OP=and&QUERY=40&RGN=BTI&QUERY=3775&RGN=BSECCT&SUBSET=SUBSET&FROM=1&ITEM=1
"(4) Inorganic pollutants. "Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods", EPA Publication SW-846, Second Edition
(1982) with Updates I (April 1984) and II (April 1985) and Third
Edition (November 1986) with Revision I (December 1987). Second
Edition and Updates I and II are available from the National Technical
Information Service, 5285 Port Royal Road, Springfield, Virginia 22161
(PB-87-120-291). Third Edition and Revision I are available from
Superintendent of Documents, Government Printing Office, 941 North
Capitol Street, NE., Washington, DC 20002 (Document Number
955-001-00000-1)"
QUESTION:
6) What constituents of raw sewage may interfere with raising the pH?
ANSWER:
None different than those in sludges.
QUESTION:
7) What other considerations should be made when treating raw sewage
with lime?
ANSWER:
From:
Stabilization of Sewage Sludges (Bio-Solids) (IBID)
"In fact the regulations (503) are very conservative. EPA research1
shows that a pH above 11, is sufficient to control all indicator
organisms. The requirement of attaining a pH of 12 (ten times the
alkalinity strength of pH 11) is certainly conservative and insures
the safety of treated sewage 1,3,5. There is no need to make
additional changes to the regulatory requirements for stabilization."
[...]
"2. Lime based alkaline material application rate: To determine proper
application rates, "jar" tests must be accomplished in the laboratory
on samples of the same sludge concentrations as the material to be
treated in the full scale process. The full scale operation will
probably require a slight revision of application rate. However, one
needs to establish a viable base application rate of the material to
be used. The end use of the treated bio-solids is often the deciding
factor as to the alkaline reagent and process specified."
See the other recommendations and cautions in the same paper.
and,
REDUCTION EFFICIENCY OF INDEX PATHOGENS IN DRY SANITATION COMPARED
WITH TRADITIONAL AND ALTERNATIVE WASTEWATER TREATMENT SYSTEMS by Thor
Axel Stenström
http://www.ecosanres.org/PDF%20files/Nanning%20PDFs/Eng/Stenstrom%2002_E07.pdf
"Ecological sanitation versus traditional treatment
Investigations have been carried out in dry latrines in different
regions of the world to get baseline values in assessing the
efficiency of dry sanitation in relation to the die-off of different
representatives of microbial groups. Traditionally evaluations are
carried out with different types of indicator organisms instead of a
direct evaluation of pathogens. This approach has also been taken with
some ecosan evaluations. In a study performed in Mexico Redlinger et
al (2001) investigated the occurrence of feacal coliforms in the
collected dry material over a 6-month period. Only about 1/3 of the
samples fulfilled the Class A values, according to the US EPA. The
reduction of the coliforms was mainly related to the desiccation, with
a higher percentage of drier samples fulfilling the regulations. 6
months storage gave lower values of coliforms. pH was not measured. US
EPA applies a classification for reuse of biosolids (for Class A
compost <1000 faecal coliforms/ g). In addition there is alternative
options to measure the absence of viruses, helminth ova and
Salmonella. EPA rules divide sludge — which it calls biosolids — into
two categories, depending on how it is treated and cleaned (EPA 1999).
The more expensive Class A treatment aims to kills all the pathogens
that live in the waste. The more common Class B treatment kills some
of the pathogens. CDC (US Center for Disease Control) is now
recommending that all sludge be cleaned to Class A in US because of
the risk that diseases could be transmitted through the Class B
sludge.
Table 2. Summary of the effects of sewage sludge treatment on
pathogens expressed as log10- reduction (from US EPA 1999).
PSRP Treatment Bacteria Viruses Parasites (protozoa & helminthes
_____________________________________________________________________
Anaerobic Digestion 0.5-4 0.5-2 0.5
Aerobic Digestion 0.5-4 0.5-2 0.5
Composting (PSRP) 2-4 2-4 2-4
Air Drying 0.5-4 0.5-4 0.5-4
Lime stabilization 0.5-4 4 0.5
In the material of the dry latrine material the destruction was mainly
governed by time and high pH. The later ensured by addition of ash,
lime or similar additives. Just addition of moisture absorbing
materials should be disregarded, as they do not ensure an as efficient
reduction. Within a time period of less than 6 months a total
destruction of Ascaris ova occurred as well as of the index viruses
used, if a pH of around 9 could be obtained. A decimal reduction
occurred during shorter time periods. Reduction of Esherichia coli was
generally faster, thereby not reflecting a die-off of non-bacterial
pathogens. Likewise in collected urine pH around 9 seems to be a major
reduction factor. Temperature also played a major role in collected
urine with a faster reduction at 20 degrees C than at 4 degrees C.
Higher temperatures have not been systematically evaluated but can be
assumed to give a faster reduction. However, viruses seem to be
reduced slower than other pathogenic groups. Temperature is a major
governing factor in reduction of most groups of pathogenic organisms.
In the dry feacal material of the latrines temperatures above 45
degrees C were not registered. If temperatures of above 50 degrees C
could be obtained a much shorter collection time could still ensure a
more or less total destruction of pathogens. This is evident when
comparing the results with a aerobic thermophilic wet composting
system, where a total destruction of both Ascaris ova, index viruses,
index bacteria as well as traditional bacterial indicator organisms
occurred within 48-72 hours at temperatures around 55 degrees C.
However, in this system a re-infection of the material with some
bacterial pathogens may result in an after-growth."
From:
Process Design Manual
Land Application of Sewage Sludge and Domestic Septage
EPA/625/K-95/001 (IBID)
"3.4 Operational Standards for Pathogens and Vector Attraction
Reduction
Subpart D of the Part 503 rule describes requirements for land
application of sewage sludge (and domestic septage, as discussed in
Chapter 11) that reduce the potential for the spread of disease, thus
protecting public health and the environment. The Part 503 Subpart D
requirements cover two characteristics of sewage sludge:
* Pathogens. Part 503 requires the reduction of potential
disease-bearing microorganisms called pathogens (such as bacteria and
viruses) in sewage sludge.
* Vector Attraction. Part 503 also requires that the potential for
sewage sludge to attract vectors (e.g., rodents, birds, insects) that
can transport pathogens away from the land application site be
reduced. Compliance with the Part 503 pathogen and vector attraction
reduction requirements, summarized below, must be demonstrated
separately.
3.4.1 Pathogen Reduction Requirements
The Part 503 pathogen reduction requirements for sewage sludge are
divided into two categories: Class A and Class B, as shown in Table
3-6. The implicit goal of the Class A requirements is to reduce the
pathogens in sewage sludge (including Salmonella sp. bacteria, enteric
viruses, and viable helminth ova) to below detectable levels. When
this goal is achieved, Class A sewage sludge can be land applied
without any pathogen-related restrictions on the site (see Section
3.7).
The implicit goal of the Class B requirements is to ensure that
pathogens have been reduced to levels that are unlikely to pose a
threat to public health and tions on the land application of Class B
sewage sludge minimize the potential for human and animal contact with
the sewage sludge until environmental factors tion, to further reduce
the likelihood of human contact with pathogens, Class B sewage sludge
cannot be sold or given away in a bag or other container for land
application. Part 503 Class A and B pathogen reduction requirements
are summarized below; another EPA document (U.S. EPA, 1992b) provides
a detailed discussion of pathogen reduction requirements under Part
503.
3.4.1.1 Class A Pathogen Requirements
Sewage sludge that must meet the Class A pathogen requirements
includes sewage sludge that is sold or given away in a bag or other
container for application to land and bulk sewage sludge that is
applied to a lawn or home garden. Part 503 Subpart D establishes six
alternatives for demonstrating that sewage sludge meets Class A
pathogen reduction requirements (Table 3-6). The rule requires that
the density of fecal coliforms be less than 1,000 Most Probable Number
(MPN) per gram total solids (dry weight) or that Salmonella sp.
bacteria be less than 3 per 4 grams total solids, as discussed in
Table 3-7.
Table 3-6. Summary of Class A and Class B Pathogen
Alternatives
CLASS A
In addition to meeting the requirements in one of the six alternatives
listed below, fecal coliform or Salmonella sp. bacterial levels must
meet specific densities at the time of sewage sludge use or disposal,
when prepared for sale or give-away in a bag or other container for
application to the land, or when prepared to meet the requirements in
503.10(b), (c), (e), or (f)
Alternative 1: Thermally Treated Sewage Sludge Use one of four
time-temperature regimes
Alternative 2: Sewage Sludge Treated in a High pH-High Temperature
Process Specifies pH, temperature, and air-drying requirements
Alternative 3: For Sewage Sludge Treated in Other Processes
Demonstrate that the process can reduce enteric viruses and viable
helminth ova. Maintain operating conditions used in the demonstration
Alternative 4: Sewage Sludge Treated in Unknown Processes
Demonstration of the process is unnecessary. Instead, test for
pathogens— Salmonella sp. bacteria, enteric viruses, and viable
helminth ova—at the time the sewage sludge is used or disposed, or is
prepared for sale or give-away in a bag or other container for
application to the land, or when prepared to meet the requirements in
503.10(b), (c), (e), or (f)
Alternative 5: Use of PFRP Sewage sludge is treated in one of the
processes to further reduce pathogens (PFRP) Alternative 6: Use of a
Process Equivalent to PFRP Sewage sludge is treated in a process
equivalent to one of the PFRPs, as determined by the permitting
authority
CLASS B
The requirements in one of the three alternatives below must be met in
addition to Class B site restrictions
Alternative 1: Monitoring of Indicator Organisms Test for fecal
coliform density as an indicator for all pathogens at the time of
sewage sludge use or disposal
Alternative 2: Use of PSRP Sewage sludge is treated in one of the
processes to significantly reduce pathogens (PSRP)
Alternative 3: Use of Processes Equivalent to PSRP Sewage sludge is
treated in a process equivalent to one of the PSRPs, as determined by
the permitting authority Note: Details of each alternative for meeting
the requirements for Class A and Class B designations are provided in
Section 3.4.
Each of the six alternatives for meeting Class A pathogen reduction
requirements includes monitoring requirements to ensure that
substantial regrowth of pathogenic bacteria does not occur after the
sewage sludge meets the pathogen reduction requirements prior to use
or disposal. The timing of Class A pathogen reduction in relation to
vector attraction reduction requirements (see Section 3.4.2) is
important when certain vector attraction reduction options are used.
Part 503 requires that Class A pathogen reduction be accomplished
before or at the same time as vector attraction reduction, except when
vector attraction reduction is achieved by alkali addition or drying.
The following discussion summarizes the Part 503 Class A pathogen
reduction alternatives. For a more complete discussion of these
alternatives, see Environmental Regulations and Technology: Control of
Pathogens and Vector Attraction in Sewage Sludge (U.S. EPA, 1992b).
Alternative 1: Thermally Treated Sewage Sludge This alternative may be
used when the pathogen reduction process relies on specific
time-temperature regimes to reduce pathogens (Table 3-8). The approach
involves calculating the heating time necessary at a particular
temperature to reduce a sewage sludge’s pathogen content to below
detectable levels. The need to conduct time-consuming and expensive
tests for the presence of specific pathogens can be avoided with this
approach. The microbiological density portion of the requirement
(i.e., the regrowth requirement) is designed to ensure that the
microbiological reductions expected as a result of the
time-temperature regimes have actually been attained and that regrowth
has not occurred. Equations for each of the four time-temperature
regimes takes into account the percent of solids in the sewage sludge
and the operating parameters of the treatment process.
Alternative 2: Sewage Sludge Treated in a High pH-High Temperature
Process This alternative may be used when the pathogen reduction
process relies on a particular high temperature-high pH process that
has been demonstrated to be effective in reducing pathogens to below
detectable levels. The high pH (>12 for more than 72 hours) and high
temperature (above 52°C [126°F] for at least 12 hours while pH is >12)
for prolonged periods allow a less stringent time-temperature regime
than the requirements under Alternative 1. After the 72-hour period
during which the pH of the sewage sludge is above 12, the sewage
sludge must be air dried to achieve a percent solids content of
greater than 50 percent. As when thermal processing is used,
monitoring for regrowth of pathogenic bacteria (fecal coliforms or
salmonellae) must be conducted (Table 3-7).
Alternative 3: Sewage Sludge Treated in Other Processes This
alternative applies to sewage sludge treated by processes that do not
meet the process conditions required by Alternatives 1 and 2.
Alternative 3 relies on comprehensive monitoring of fecal coliform or
Salmonella sp. bacteria; enteric viruses; and viable helminth Table
3-7. Pathogen Requirements for All Class A Alternatives The following
requirements must be met for all six Class A pathogen alternatives.
Either:
* the density of fecal coliform in the sewage sludge must be less than
1,000 most probable number (MPN) per gram total solids (dry-weight
basis),
or
* the density of Salmonella sp. bacteria in the sewage sludge must be
less than 3 MPN per 4 grams of total solids (dry-weight basis). This
requirement must be met at one of the following times:
* when the sewage sludge is used or disposed;
* when the sewage sludge is prepared for sale or give-away in a bag or
other container for land application; or
* when the sewage sludge or derived material is prepared to meet the
Part 503 requirements in 503.10(b), (c), (e), or (f) Pathogen
reduction must take place before or at the same time as vector
attraction reduction, except when the pH adjustment or percent solids
vector attraction reduction options are met, or if vector attraction
reduction is accomplished through injection or incorporation.
Table 3-8. The Four Time-Temperature Regimes for Pathogen Reduction
Under Class A, Alternative 1 Regime Applies to: Requirement
Time-Temperature Relationship a A Sewage sludge with 7% solids or
higher (except those covered by Regime B) Temperature of sewage sludge
must be 50 o C or higher for not less than 20 minutes D = 131,700,000
10 0.1400 T (Equation 3 of Section 503.32)
B Sewage sludge with 7% solids or higher in the form of small
particles heated by contact with either warmed gases or an immiscible
liquid Temperature of sewage sludge must be 50 o C or higher for not
less than 15 seconds D = 131,700,000 10 0.1400 T
C Sewage sludge with less than 7% solids Heated for more than 15
seconds but less than 30 minutes D = 131,700,000 10 0.1400 T
D Sewage sludge with less than 7% solids Temperature of sludge is 50 o
C or higher with at least 30 minutes contact time D = 50,070,000 10
0.1400 T (Equation 4 of Section 503.32) a D = time in days; T =
temperature in degrees Celsius."
See also:
CODE OF FEDERAL REGULATIONS TITLE 40
TITLE 40 CFR PROTECTION OF THE ENVIRONMENT
http://www.epa.gov/epahome/cfr40.htm
Part 503--STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE
http://www.access.gpo.gov/nara/cfr/cfrhtml_00/Title_40/40cfr503_00.html
40 CFR - CHAPTER I - PART 503 Appendix B to Part 503 -- Pathogen
Treatment Processes
http://ecfr1.access.gpo.gov/otcgi/cfr/otfilter.cgi?DB=1&ACTION=View&QUERY=40&RGN=BTI&OP=and&QUERY=503&RGN=BPT&OP=and&QUERY=3510&RGN=BAPPCT&SUBSET=SUBSET&FROM=1&ITEM=1
§ 503.8 SAMPLING AND ANALYSIS
http://ecfr1.access.gpo.gov/otcgi/cfr/otfilter.cgi?DB=1&ACTION=View&QUERY=503.8&RGN=BSEC&OP=and&QUERY=40&RGN=BTI&QUERY=3775&RGN=BSECCT&SUBSET=SUBSET&FROM=1&ITEM=1
§ 503.32 PATHOGENS
http://frwebgate.access.gpo.gov/cgi-bin/DBSearch.cgi?DBSearchDB=ecfr&DB=1&ACTION=View&QUERY=503.32&RGN=BSEC&OP=and&QUERY=40&RGN=BTI&QUERY=15292&RGN=BSECCT&SUBSET=SUBSET&FROM=1&ITEM=1
§ 503.33 VECTOR ATTRACTION REDUCTION.
http://frwebgate.access.gpo.gov/cgi-bin/DBSearch.cgi?DBSearchDB=ecfr&DB=1&ACTION=View&QUERY=503.33&RGN=BSEC&OP=and&QUERY=40&RGN=BTI&QUERY=5573&RGN=BSECCT&SUBSET=SUBSET&FROM=1&ITEM=1
EPA DOCUMENTS ONLINE
(Unfortunately, many EPA documents can be viewed online only in .TIF,
one page at a time, and not always with success. However, some useful
documents are stored in this manner.)
The National Environmental Publications Information System NEPIS
http://www.epa.gov/nepis/
http://www.epa.gov/clariton/clhtml/pubindex.html
600479020 Methods for Chemical Analysis of Water and Wastes
http://www.epa.gov/cgi-bin/claritgw?op-Display&document=clserv:ORD:0167;&rank=4&template=epa
SW84633A Test Methods for Evaluating Solid Waste: Physical/Chemical
Methods; Third Edition; Final Update 3A
http://www.epa.gov/cgi-bin/claritgw?op-Display&document=clserv:Other:0969;&rank=4&template=epa
U.S. EPA, 1994. Guide to Septage Treatment and Disposal. EPA Office of
Research and Development. Washington, D.C. EPA/625/R-94/002.
http://www.epa.gov/cgi-bin/claritgw?op-Display&document=clserv:ORD:2055;&rank=4&template=epa
OTHER EPA REFERENCE DOCUMENTS
U.S. EPA, 1984. Handbook: Septage Treatment and Disposal. EPA
Municipal
Environmental Research Laboratory. Cincinnati, Ohio. EPA-625/6-84-009.
Environmental Regulations and Technology: Control of Pathogens and
Vector Attraction in Sewage Sludge. 1992. Office of Research and
Development.
EPA/625/R-92/013.
Preparing Sewage Sludge For Land Application Or Surface Disposal: A
Guide for Preparers of Sewage Sludge on the Monitoring, Record
Keeping, and Reporting Requirements of the Federal Standards for the
Use or Disposal of Sewage Sludge, 40 CFR Part 503. 1993. Office of
Water. EPA 831 B-93-002.
A Plain English Guide to the EPA Part 503 Biosolids Rule. 1994. Office
of Wastewater Management. EPA/832/R-93/003.
Domestic Septage Regulatory Guidance: A Guide to the EPA 503 Rule.
1993. Office of Water. EPA 832-B-92-005.
U.S. EPA. 1994a. A plain English guide to the Part 503 biosolids rule.
EPA/832/R-93/003. Washington, DC.
U.S. EPA. 1994b. Guide to septage treatment and disposal.
EPA/625/R-94/002. Cincinnati, OH.
U.S. EPA. 1993. Domestic septage regulatory guidance: A guide to the
Part 503 rule. EPA/832/B-92/005. Washington, DC.
U.S. EPA. 1992a. Technical support document for land application of
sewage sludge. EPA/822/R-93/001a (NTIS PB93110583). Washington, DC.
U.S. EPA. 1992b. Environmental regulations and technology: Control of
pathogens and vector attraction in sewage sludge. EPA/625/R-92/013.
Washington, DC.
U.S. EPA. 1980. Septage management. EPA/600/8-80/032. (NTIS PB
81142481). Washington, DC.
WHO RESOURCES
World Health Organization (WHO)
Water and Sanitation - Sanitation and Health Index
http://www.who.int/water_sanitation_health/index.html
Managing Water in the Home: Accelerated Health Gains from Improved
Water Supply. Geneva, WHO, 2002.WHO/SDE/WSH/02.07.
http://www.who.int/water_sanitation_health/Documents/WSH0207/wsh0207-7.htm
APPALACHIAN TRAIL CONFERENCE
Backtrail Sanitation Manual
http://www.appalachiantrail.org/protect/steward/sanman.html
Descriptions of Systems (PDF, 582 KB)
Moldering and batch-bin composting systems, with a description of
liquid separation techniques. The moldering toilet system offers new
opportunities for quality sanitation management in the backcountry.
[pages 45-96]
http://www.appalachiantrail.org/protect/pdfs/sanmanD.pdf
Appendices (PDF, 1.4 MB)
A wealth of additional information such as a glossary of terms,
troubleshooting and general composting tips, examples of stewardship
signs, designs for various toilet systems and examples of regulatory
correspondence. [pages 133-213]
http://www.appalachiantrail.org/protect/pdfs/sanmanHrevisedJan03.pdf
ECOLOGICAL SANITATION
About Ecological Sanitation
http://www.ecosan.nl/ecosan.html
Internet Dialogue on Ecological Sanitation
http://www.ias.unu.edu/proceedings/icibs/ecosan/liu01.html
Internet Dialogue on Ecological Sanitation
http://www.ias.unu.edu/proceedings/icibs/ ecosan/corella-barud.html
[PDF]The first International Conference on Ecological sanitation: ...
File Format: PDF/Adobe Acrobat
http://www.gtz.de/ecosan/docs/Nanning-Summary-Report.pdf - Similar
pages
Eco-San (Ecological Sanitation) References and Web Links
http://www20.brinkster.com/microfarm/My_Links_Pages/
eco-san_refs_01.html
The Water Page - EcoSanitation - Latrine design
http://www.thewaterpage.com/ecosan_design.htm
[PDF]MICROBIOLOGICAL STUDIES OF ECOLOGICAL SANITATION IN EL SALVADOR
File Format: PDF/Adobe Acrobat
http://www.ecosanres.org/PDF%20files/Nanning%20PDFs/
Eng/Moe%20et%20al%20%2030_E42.pdf
[PDF]Introduction to the Development of Ecological Sanitation Systems
...
File Format: PDF/Adobe Acrobat
http://www.ecosanres.org/PDF%20files/Nanning%20PDFs/
Eng/Li%20Zifu%2015_E10A.pdf
[PDF]UA-Magazine 3¥1.4.web
File Format: PDF/Adobe Acrobat
http://www.ruaf.org/1-3/35-37.pdf
PHG Projects
http://www.phg.org/dry/dry_sanitation.html
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