(1) GENERAL. No
person may land apply sludge in a manner which does not comply with the
requirements of a WPDES permit and this chapter.
(2) APPROVED SITES. The permittee shall
obtain written or computer generated approval from the department for each site
on which sludge is applied in bulk prior to land application, unless the
permittee is authorized to inspect and approve their own sites under s.
NR
204.06(6). The department shall
review and issue either approval, conditional approval or denial within 60
business days following receipt of the site's complete application, unless
weather conditions preclude adequate site evaluation. Each site shall be
reviewed based on information contained in the report required by s.
NR
204.06(6). Failure to comply with the
conditions of the site approval may result in the revocation of the approval
and be considered a violation of the permit. Reapproval shall be contingent on
submittal of an operations report for the site which shall specify how further
violations will be avoided. When a permittee contracts with another party to
land apply sludge and the land applier is not required to hold its own WPDES
permit under s.
NR
204.05, the permittee maintains responsibility, as
well as the land applier, for compliance with the WPDES permit and this
chapter. The permittee shall supply the land applier with all information
necessary to ensure compliance. The land applier shall also make reasonable
attempts to obtain all information needed to ensure compliance with this
chapter.
(3) OPERATIONAL AND SITE
OR FIELD REQUIREMENTS.
(a) Bulk sludge may
not be applied to the land if it is likely to adversely affect a threatened or
endangered species or its designated critical habitat, or a designated
historical site.
(b) Bulk sludge
may only be applied to sites that meet the requirements in Table B. Other
sites, as specified in s.
NR
204.09, may be approved by the department in writing
on a case-by-case basis.
(c) Bulk
sludge may not be applied to soils with a high groundwater level or bedrock at
a depth of less than 3 feet. Exceptions may be granted by the department on a
case-by-case basis. Parameters which may be considered for exceptions include:
demonstration that the soil has an available water holding capacity that is
greater than 5 inches, above the high groundwater level or bedrock; whether the
high groundwater is a seasonal condition; depth of saturation at the proposed
time of application to determine whether a seasonal use approval may be granted
and other relevant site specific conditions.
(d) Bulk sludge may not be applied on sites
with soils which have a rapid permeability of greater than 6 inches per hour
unless, through consideration of the sludge characteristics, loading rate,
cropping practices and other soil characteristics, department approval is
obtained.
(e) The pH of the soil
shall be 5.5 or greater at the time the bulk sludge is applied, unless after
consideration of the sludge quality, cropping practices and soil
characteristics of the site, the department determines that the pH should be
higher to protect the environment or public health.
(f) If the soil at a site or field is
classified as highly erodible on the United States department of agriculture's
county by county soil conservation service soil survey, the department may
impose additional management practices, such as soil conservation practices, to
minimize erosion from the site.
(g)
Class B sludge, as specified in sub. (6) (b), that is land applied to sites
shall have restricted public access for a period of 30 days for low exposure
sites such as a farm field, and one year for high exposure sites such as a city
park, following sludge application. Access may be restricted by the location of
the site on private property, fencing or posting the application site, or other
department approved methods that minimize human contact with the
sludge.
(h) Bulk sludge shall be
applied in a manner to minimize soil compaction, to prevent surface runoff and
to control objectionable odors. Sludge may not be applied on saturated soils,
during significant rainfall events or in areas with ponded water or to areas
which are subject to ponding.
(i)
Bulk sludge land application vehicles or equipment shall be moving at all times
while sludge is being applied to ensure uniform application. Uniform
application shall be accomplished for surface application vehicles by the use
of a splash plate, spreader bar, beaters, expellers or other department
approved methods.
(j) Bulk sludge
transporting vehicles and equipment may not leak sludge during use, transport,
operation or storage. Vehicles utilized for the land application of liquid
sludge shall have cab actuated discharge valves.
(k) Sludge which has a PCB concentration
greater than 50 mg/kg (dry weight) may not be applied unless a management plan
is approved by the U.S. EPA region V administrator pursuant to
40 CFR
761.60(a) (5)
(iii). Sludge with a PCB concentration
greater than 10 mg/kg (dry weight) shall be injected or incorporated into the
soil.
(l) Application of bulk
sludge, by any person, on frozen or snow covered ground is prohibited unless it
is demonstrated, to the satisfaction of the department, that there are no other
reasonable disposal methods available and there is absolutely no likelihood
that the sludge will enter the waters of the state, or except as provided in
par. (m).
(m) Application of bulk
sludge on frozen or snow covered soils may be approved by the department on a
case-by-case basis until storage is available, as required in s.
NR 204.10.
Department approvals for application on frozen or snow covered soils shall
require the following restrictions at a minimum:
1. Sites or fields used shall have slopes
less than or equal to 2%.
2. An
application rate of less than 10,000 gal/acre.
3. Application is not allowed within 750 feet
of any surface water, wetland or floodplain.
(n) When a WPDES permit requires testing for
radium-226 and the sludge is subsequently found to contain radium-226, the land
application of the sludge shall be terminated when the soil level of radium-226
equals or exceeds 2 picocuries per gram of soil on a dry weight basis in the
top 12 inches of soil. In addition to other criteria in this section, the
following conditions shall be adhered to when land applying sludge containing
radium-226:
1. The soil pH shall be at least
6.0 prior to the application of sludge containing radium-226. This pH shall be
maintained during the period the site is used for the land application of
sludge containing radium-226.
2.
The soil shall have at minimum a 6 inch layer with a clay content of at least
18% within the top 5 feet of the soil profile and be above the seasonal high
groundwater level and bedrock. This determination shall be based primarily on
the detailed county soil survey books.
3. The soil shall have at minimum a 6 inch
layer with an organic matter content of at least 12 tons/acre within the top 5
feet of soil and be above seasonal high groundwater or bedrock. This
determination shall be based primarily on the on-site soil test.
4. The department may on a case-by-case basis
conditionally approve fields that do not meet all criteria established in
subds. 1. to 3., where evaluation of sludge characteristics, soil features and
management practices indicate no adverse impacts to the environment or public
health would result.
5. Sludge
containing radium-226 may not be applied to fields used for the production of
tobacco.
6. Application of
radium-226 sludge shall be terminated when the calculated site loading reaches
1640 microcuries per acre. To continue site use, the permittee shall sample
soils according to a plan approved by department, and show that soil radium-226
activity is below 2 pCi/g in the top foot of soil.
Note: 1 microcurie = 10-6 curies, 1 picocurie = 10-12
curies
7. If plant tissue
sampling for radium-226 is required by the department in the permit, it shall
be done in accordance with a department approved method. The number of plant
tissue samples obtained shall be identical to the number of subsamples needed
to constitute a composite soil sample and shall yield a wet weight of
approximately 4 pounds. The entire above ground plant shall be obtained as near
as possible to the soil subsample site. Plant samples shall then be segregated
between the above ground tissue, such as stems, stalks, petioles or leaves, and
the "edible" portion, such as fruit, grain or seed.
(o) Table B site restrictions apply to all
sludges that are applied to land in bulk unless prior department approval has
been received. The distances stated in Table B are minimums. Table C applies to
all bulk sludge designated as Class B with respect to pathogens that is applied
to land. The intervals of time listed in Table C refer to the time period
between the sludge application and harvesting. The permittee or land applier
shall supply the farmer with the information in Table C, in a timely manner, to
ensure compliance with these requirements.
Table B
Sludge Applied to the Land in Bulk
|
Site Criteria
|
Surface
|
Incorporation
|
Injection
|
|
Depth to bedrock
|
3 ft.
|
3 ft.
|
3 ft.
|
|
Depth to high groundwater
|
3 ft.
|
3 ft.
|
3 ft.
|
|
Allowable slopes
|
0-6%
|
0-12%
|
0-12%
|
|
Distance to wells
|
|
|
|
|
-Community water supply or school
|
1000 ft.
|
1000 ft.
|
1000 ft.
|
|
-Other*
|
250 ft.
|
250 ft.*
|
250 ft.*
|
|
Minimum distance to residence, business or
recreation area
|
500 ft.
|
200 ft.
|
200 ft.
|
|
Minimum distance to residence or business
w/permission
|
250 ft.
|
100 ft.
|
100 ft.
|
|
Distance to rural schools and health care
facilities
|
1000 ft.
|
1000 ft.
|
500 ft.
|
|
Distance to property line
|
50 ft.**
|
25 ft.**
|
25 ft.**
|
Minimum distance to streams, lakes, ponds, wetlands or
channelized waterways connected to a stream, lake, pond or wetland.
|
-Slope 0 to < 6
|
200 ft.
|
150 ft.
|
100 ft.
|
|
-Slope 6 to <12
|
Not allowed
|
200 ft.
|
150 ft.
|
Minimum distance to grass waterways, or dry run with a 50
foot range grass strip. ***
|
-Slope 0 to <6
|
100 ft.
|
50 ft.
|
25 ft.
|
|
-Slope 6 to <12
|
Not allowed
|
100 ft.
|
50 ft.
|
|
Soil permeability range (in/hr)
|
0.2-6.0
|
0-6.0
|
0-6.0
|
* Separation distances to non-potable wells used for
irrigation or monitoring may be reduced to 50 ft. if the sludge is incorporated
or injected and the department does not determine that a greater distance to
the wells is required to protect the groundwater.
** The distances to property lines may be reduced with the
written permission of both property owners.
*** Separation distances not required if grass waterway or
dry run with grass strip is contained within a site or field for the purpose of
erosion control.
(4) SLUDGE QUALITY (STANDARDS AND PROCESSES).
(a) In addition to other requirements in this
chapter, there are 3 categories of requirements of sludge quality which must be
satisfied before the sludge may be applied to land. The categories are listed
in subs. (5), (6) and (7). They are metal concentrations, pathogen densities
and treatment processes, and vector attraction reduction. Each category is
divided into 2 levels which determine a higher or lower quality of sludge. They
are: for metals-pollutant concentrations and ceiling concentrations, specified
in sub. (5); for pathogens-class A and class B, specified in sub. (6); and for
vector attraction reduction-treatment processes and physical barriers,
specified in sub. (7). A sludge shall meet the minimum, or lower quality,
requirements for each category in order to be land applied. When a sludge meets
the higher quality level in all 3 categories, it is considered exceptional
quality sludge. When a sludge meets the higher level in the metals category it
is considered high quality and exempt from tracking cumulative metal loadings
to the application sites.
(b) When
a sludge is exceptional quality or when it is bagged and satisfies the
requirements in sub. (5) (c) or (d), it may be used on lawns or home gardens.
Sludge not meeting those requirements may not be used on lawns or home
gardens.
(c) Sludge that will be
sold or given away in a bag shall, at a minimum, satisfy the class A pathogen
requirements in sub. (6) (a), one of the vector attraction reduction process
requirements in sub. (7) (a) to (i) and either the high quality pollutant
concentration limits in Table 3 or the ceiling concentration limits in Table 1.
Bagged sludge that does not meet the high quality limits in Table 3 is subject
to the requirements in sub. (5) (d).
Table C
Minimum Duration Between Application and
Harvest\grazing\access for Class B Sludge Applied to the Land
|
Criteria
|
Surface
|
Incorporation
|
Injection
|
|
Food crops whose harvested part may touch the
soil/sludge mixture (beans, melons, squash, etc.)
|
14
months
|
14 months
|
14
months
|
|
Food crops whose harvested parts grow in the soil
(potatoes, carrots, etc.)
|
20/38 months*
|
20/38 months*
|
38 months
|
|
Feed or other food crops (field corn, hay, sweet
corn, etc.)
|
30 days
|
30 days
|
30 days
|
|
Grazing of animals
|
30 days
|
30 days
|
30 days
|
|
Public access restriction
|
|
-High potential**
|
1 year
|
1 year
|
1 year
|
|
-Low potential
|
30 days
|
30 days
|
30 days
|
*The 20 month duration between application and harvesting
applies when the sludge that is surface applied stays on the surface for 4
months or longer prior to incorporation into the soil. The 38 month duration is
in effect when the sludge remains on the surface for less than 4 months prior
to incorporation.
**This includes application to turf farms which place turf
on land with a high potential for public exposure.
(5) METAL CONCENTRATIONS.
(a) Table 1 lists the ceiling concentrations
of metal pollutants for sludge that is land applied. Sludge may not be applied
to land if the concentration of pollutants in the sludge exceeds any of the
ceiling concentration limits established in Table 1. Options available if a
ceiling concentration in sludge is exceeded include: retesting, mixing with
another sludge or other material and demonstration of compliance with Table 1,
landfilling or incinerating.
(b)
Table 2 lists the cumulative metal pollutant loading limits for sites on which
bulk sludge is applied. If bulk sludge is applied to land and the sludge does
not meet the pollutant concentration limits in Table 3, then the limits in
Table 2 shall apply to all land application sites. Bulk sludge that does not
meet the Table 3 concentration limits may not be applied to sites where the
cumulative pollutant loading limits in Table 2 have been reached. When bulk
sludge that does not meet Table 3 limits is applied to land, the permittee
shall monitor and retain cumulative pollutant loadings records to each site,
and shall notify the department, in their annual report, when any site reaches
90% of the allowable cumulative loading for any metal established in Table
2.
(c) Sludge shall meet all the
pollutant concentration limits established in Table 3, to be considered high
quality. High quality sludge is exempt from the cumulative loading limits
specified in par. (b).
Table 1
Ceiling Concentrations
|
Pollutant
|
Ceiling concentrations (milligrams per
kilogram-ppm) (dry weight)
|
|
Arsenic
|
75
|
|
Cadmium
|
85
|
|
Copper
|
4300
|
|
Lead
|
840
|
|
Mercury
|
57
|
|
Molybdenum
|
75
|
|
Nickel
|
420
|
|
Selenium
|
100
|
|
Zinc
|
7500
|
Table 2
Lifetime Cumulative Metal Loadings
|
Pollutant
|
Kg/ha
|
lbs/ac
|
|
Arsenic
|
41
|
36
|
|
Cadmium
|
39
|
34
|
|
Copper
|
1500
|
1339
|
|
Lead
|
300
|
268
|
|
Mercury
|
17
|
15
|
|
Molybdenum
|
Deleted Until EPA
|
Revises
|
|
Nickel
|
420
|
375
|
|
Selenium
|
100
|
89
|
Note: The department strongly encourages permittees to
produce sludge which meets the high quality pollutant concentration limits set
in Table 3.
Table 3
Pollutant Concentrations
|
Pollutant
|
Monthly average concentrations (milligrams
per kilogram-ppm) (dry weight)
|
|
Arsenic
|
41
|
|
Cadmium
|
39
|
|
Copper
|
1500
|
|
Lead
|
300
|
|
Mercury
|
17
|
|
Molybdenum
|
Deleted Until EPA Revises
|
|
Nickel
|
420
|
|
Selenium
|
100
|
|
Zinc
|
2800
|
(d)
1. Table 4 lists the maximum annual pollutant
loading rates for sites where bagged sludge that is not high quality is land
applied. If bagged sludge does not meet all of the pollutant concentrations in
Table 3, the pollutant loading requirements in Table 4 apply to all land
application sites utilized, including lawns and home gardens. To ensure that
the annual pollutant loading rates in Table 4 are not exceeded, the amount of
sludge applied annually shall be less than the annual sludge application rate
calculated as follows:
ASAR = (APLR) / (C X 0.001)
Where:
ASAR = Annual sludge application rate in metric tons per
hectare per 365 day period calculated on a dry weight basis.
APLR = Annual pollutant loading rate for a pollutant in
kilograms per hectare per 365 day period, as stated in Table 4.
C = Pollutant concentration in milligrams, per kilogram of
total solids calculated on a dry weight basis.
0.001 = A conversion factor.
2. When distributing bagged sludge that is
subject to the Table 4 loading rates, the permittee shall provide an
information sheet to each person receiving the bagged sludge or shall print
instructions on the bag or container or label. The label instructions or
information sheet shall contain the following information, at a minimum:
a. The name and address of the permittee who
generated the sludge.
b. A
statement that prohibits the use of the sludge except in accordance with the
instructions on the label or information sheet.
c. An annual sludge application rate as
calculated in this subsection that will ensure that the annual pollutant
loading rate limits, established in Table 4, are not exceeded.
d. The percentage content of nitrogen,
phosphorus and potassium present in the sludge.
Table 4
Annual Pollutant Loading Rate
|
Pollutant
|
Kg/ha
|
lbs/ac
|
|
Arsenic
|
2.0
|
1.78
|
|
Cadmium
|
1.9
|
1.69
|
|
Copper
|
75
|
66.9
|
|
Lead
|
15
|
13.4
|
|
Mercury
|
0.85
|
0.76
|
|
Molybdenum
|
Deleted Until EPA
|
Revises
|
|
Nickel
|
21
|
18.7
|
|
Selenium
|
5
|
4.4
|
|
Zinc
|
140
|
125
|
(6) PATHOGEN DENSITIES AND TREATMENT
PROCESSES. Sludge may not be land applied unless the Class A pathogen
requirements in par. (a) or the Class B pathogen requirements in par. (b) are
satisfied. These requirements are summarized in Tables 5 and 6. Bagged sludge
and exceptional quality sludge shall satisfy the Class A requirements in par.
(a).
(a) One of the requirements in each
subds. 1. and 2. shall be met for sludge to be classified as Class A. Class A
requirements shall be met prior to or at the time of meeting the vector
attraction reduction requirements specified in sub. (7), unless the process
used to meet the vector requirements is one of either sub. (7) (f), (g) or (h).
Class A requirements are summarized in Table 5:
Table 5
Class A
|
Parameter
|
Unit
|
Limit
|
|
Fecal Coliform
|
MPN/g TS
|
1000
|
|
or
|
|
|
|
Salmonella
|
MPN/4g TS
|
3
|
|
AND, ONE OF THE FOLLOWING PROCESS OPTIONS
|
|
Temp/Time based on % Solids
|
Alkaline Treatment
|
|
Prior test for Enteric Virus/Viable Helminth
Ova
|
Post test for Enteric Virus/Viable Helminth
Ova
|
|
Composting
|
Heat Drying
|
|
Heat Treatment
|
Thermophilic Aerobic Digestion
|
|
Beta Ray Irradiation
|
Gamma Ray Irradiation
|
|
Pasteurization
|
PFRP Equivalent Process
|
1. Pathogen or
indicator organism densities. The required fecal coliform density or salmonella
density shall be satisfied immediately after the treatment process in subd. 2.
is completed. If the material is bagged or distributed at that time, no
re-testing is required. If the material is bagged, distributed or land applied
at a later time, the sludge shall be retested and the requirements of subd. 1.
a. or b. satisfied at that time also, to ensure that regrowth of the organisms
has not occurred.
a. The sludge shall have a
fecal coliform density equal to or less than 1,000 most probable number (MPN)
per gram of total solids on a dry weight basis. Compliance with this
requirement shall be demonstrated by calculating the geometric mean of at least
7 separate samples; or
b. The
sludge shall have a salmonella density equal to or less than 3 MPN per 4 grams
of total solids on a dry weight basis; and
2. Pathogen treatment processes.
a. Satisfy the requirements as specified in
40 CFR
503.32(a).
40 CFR
503.32(a) as stated on
January 1, 1996 is incorporated by reference; or
Note: Copies of this section are available for inspection in
the offices of the department of natural resources, secretary of state, and the
legislative reference bureau, Madison, Wisconsin, or may be purchased from the
superintendent of documents, U.S. government printing office, Washington DC
20402.
b. Compost the
sludge using either within-vessel or static aerated pile composting methods and
maintain the temperature of the sludge at 55° C or higher for 3 days, or
compost the sludge using windrow composting methods and maintain the
temperature of the sewage sludge at 55° C or higher for 15 days or longer.
During this period, a minimum of 5 windrow turnings are required; or
c. Dry the sludge by direct or indirect
contact with hot gases to reduce the moisture content of the sludge to 10% or
lower. Either the temperature of the sewage sludge particles shall exceed
80° C or the wet bulb temperature of the gas in contact with the sludge as
the sludge leaves the dryer shall exceed 80° C; or
d. Heat liquid sludge to a temperature of
180° C or higher for 30 minutes; or
e. Agitate liquid sludge with air or oxygen
to maintain aerobic conditions. The mean cell residence time for the sludge
shall be 10 days at 55° to 60° Celsius; or
f. Irradiate the sludge with beta rays from
an accelerator at dosages of at least 1.0 megarad at room temperature;
or
g. Sludge is irradiated with
gamma rays from certain isotopes, such as Cobalt 60 and Cesium 137, at dosages
of at least 1.0 megarad at room temperature; or
h. Maintain the temperature of the sludge at
70° Celsius or higher for 30 minutes or longer; or
i. Treat the sludge in a process that is
equivalent to a process to further reduce pathogens, as approved by the
department.
(b) Either subd. 1. or one of the
requirements in subd. 2. shall be met for the sludge to be classified as Class
B. The Class B requirements are summarized in Table 6:
Table 6
Class B
|
Parameter
|
Unit
|
Limit
|
|
Fecal Coliform
|
MPN or CFU/g TS
|
2,000,000
|
|
OR ONE OF THE FOLLOWING PROCESS OPTIONS
|
|
Aerobic Digestion
|
Air Drying
|
|
Anaerobic Digestion
|
Composting
|
|
Alkaline Stabilization
|
PSRP Equivalent
|
1. Fecal
coliform density. The sludge shall have a fecal coliform density of less than
or equal to 2,000,000 most probable number (MPN) or colony forming units (CFU)
per gram of total solids on a dry weight basis. Compliance with this
requirement shall be demonstrated by calculating the geometric mean of at least
7 separate samples; or
2. Pathogen
treatment processes.
a. Agitate the sludge
with air or oxygen to maintain aerobic conditions for a mean cell residence
time and temperature between 40 days at 20° C and 60 days at 15° C;
or
b. Dry the sludge on sand beds
or on paved or unpaved basins for a minimum of 3 months. During 2 of the 3
months, the ambient average daily temperature shall be above 0° C;
or
c. Treat the sludge in the
absence of air for a specific mean cell residence time at a specific
temperature. Values for the mean cell residence time and temperature shall be
between 15 days at 35° to 55° C and 60 days at 20° C; or
d. Compost the sludge using either the
within-vessel, static aerated pile, or windrow composting methods and raise the
temperature of the sludge to 40° C or higher for 5 days. For 4 hours during
the 5 days, the temperature in the compost pile shall exceed 55° C;
or
e. Add sufficient lime to the
sludge to raise the pH to 12 after 2 hours of contact; or
f. Treat the sludge in a process that is
equivalent to a process to significantly reduce pathogens, as approved by the
department.
(7) VECTOR ATTRACTION REDUCTION. Sludge may
not be land applied unless one of the 11 vector attraction reduction options in
pars. (a) to (k) is satisfied. Paragraphs (a) to (i) are processes which treat
the sludge to reduce its attraction to vectors. Bagged sludge and exceptional
quality sludge shall satisfy one of the requirements in pars. (a) to (i). The
options are summarized in Table 7.
(a) The
mass of volatile solids in the sludge shall be reduced by a minimum of 38%
between the time the sludge enters the digestion process and the time it either
exits the digester or a storage facility; or
(b) The specific oxygen uptake rate SOUR for
aerobic sludge shall be equal to or less than 1.5 milligrams of oxygen per hour
per gram of total solids on a dry weight basis, corrected to 20° Celsius;
or
(c) Demonstrate through
additional digestion, in a bench-scale test, that additional volatile solids
reduction for anaerobically digested sludge is less than 17%. This shall be
demonstrated by digesting a portion of the previously digested sludge
anaerobically in the laboratory in a bench-scale unit for 40 additional days at
a temperature between 30° and 37° Celsius. This requirement is
satisfied when, at the end of the test, volatile solids have been reduced by
less than 17%, as measured from the beginning to the end of the test;
or
(d) Demonstrate through
additional digestion, in a bench scale test, that additional volatile solids
reduction for aerobically digested sludge is less than 15%. This shall be
demonstrated by digesting a portion of the previously digested sludge, at a
concentration of 2% solids or less, aerobically in the laboratory in a
bench-scale unit for 30 additional days at a temperature of 20° Celsius.
Sludge with higher percent solids shall be diluted with effluent down to 2% at
the start of the test. This requirement is satisfied when, at the end of the
test, volatile solids have been reduced by less than 15%, as measured from the
beginning to the end of the test; or
(e) Sludge shall be treated in an aerobic
process for 14 days or longer. During that time, the temperature of the sludge
shall be higher than 40°Celsius and the average temperature of the sludge
shall be higher than 45°Celsius; or
(f) The pH of the sewage sludge shall be
raised to 12 or higher by alkali addition and, without the addition of more
alkali, shall remain at 12 or higher for 2 hours and then at 11.5 or higher for
an additional 22 hours; or
(g) Dry
the sludge to 75% total solids when the sludge contains no unstabilized solids
from primary treatment; or
(h) Dry
the sludge to 90% total solids when the sludge contains unstabilized solids
from primary treatment; or
(i)
Treat the sludge in a process which is equivalent to one of the vector
attraction reduction requirements specified in pars. (a) to (h), as approved by
the department.
Table 7
Vector Attraction Reduction
(One of the following shall be
satisfied)
|
Option
|
Limit
|
Where/When Requirements
Must Be Met
|
|
Volatile Solids Reduction
|
>=38%
|
Across the process
|
|
Specific Oxygen Uptake Rate
|
<=L5 mg O2/hr/g TS
|
On aerobic stabilized sludge
|
|
Anaerobic benchscale test
|
<17% VS reduction
|
On anaerobic digested sludge
|
|
Aerobic benchscale test
|
<15% VS reduction
|
On aerobic digested sludge
|
|
Aerobic Process
|
>14 days, T >40°C and avg T
>45°C
|
On composted sludge
|
|
pH adjustment
|
>12 S.U.
(for 2 hours) and >1L5 (for an additional 22
hours)
|
When applied or bagged
|
|
Drying without primary solids
|
>75 % TS
|
When applied or bagged
|
|
Drying with primary solids
|
>90 % TS
|
When applied or bagged
|
|
Equivalent process
|
Determined by the department
|
Varies with process
|
|
Injection
|
-
|
When applied
|
|
Incorporation
|
-
|
When applied
|
(j)
Injection below the soil surface
1. No
significant amount of the sludge shall be present on the land surface within
one hour after the sludge is injected.
2. If the injected sludge is Class A, the
sludge shall be injected within 8 hours after being discharged from the
pathogen treatment process; or
(k) Incorporation
1. Class B sludge shall be incorporated
within 6 hours, unless otherwise specified by the department.
2. Class A sludge shall be surface applied
within 8 hours after being discharged from a pathogen treatment process. It
then shall be incorporated within 6 hours of surface application, unless
otherwise specified by the department.
(8) APPLICATION RATES.
(a) The amount of available nitrogen from
sludge and other nitrogen sources applied per growing season may not exceed the
nitrogen requirement of the crop, as determined by recommendations based on the
University of Wisconsin-extension bulletin A-2100, dated April 1991 and
incorporated by reference in s.
NR 204.06(6)
(c). The department may authorize exceptions
to this requirement on a case-by-case basis. Review for exceptions will
consider proposals such as mine or other site reclamation projects.
(b) Unless specific mineralization rates are
determined by the permittee, the following mineralization rates are to be used
in calculating the available organic nitrogen from initial sludge application
and from carryover of previous years' application: 25%-12%-6% in years 1
through 3.
(c) Bulk sludge may be
applied to all leguminous crops, except soybeans, at a volume sufficient to
supply 200 pounds per acre of available nitrogen. If sludge is applied to
soybeans, the loading shall be limited to 140 pounds per acre of available
nitrogen.
(d) Bulk sludge that is
land applied and does not meet the pollutant concentrations in Table 3 of sub.
(5) (c) may not be applied if the cumulative metals loadings listed in Table 2
of sub. (5) (b) have been reached.
(e) The department shall be notified in
writing, by the permittee, when 90% of the lifetime cumulative metal loadings
has been reached on any site or field. From that point on, all loading to that
site or field shall be individually monitored and reported.
(f) The department may, on a case-by-case
basis in the permit, require additional monitoring and limit the land
application of sludge containing pollutants that may result in environmental
degradation or threaten public health.
