NR 204.07(6)(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:
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See PDF for table 
NR 204.07(6)(a)1.
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.
NR 204.07(6)(a)1.a.
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
NR 204.07(6)(a)1.b.
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
NR 204.07 Note
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.
NR 204.07(6)(a)2.b.
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
NR 204.07(6)(a)2.c.
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
NR 204.07(6)(a)2.d.
d. Heat liquid sludge to a temperature of 180
° C or higher for 30 minutes; or
NR 204.07(6)(a)2.e.
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
NR 204.07(6)(a)2.f.
f. Irradiate the sludge with beta rays from an accelerator at dosages of at least 1.0 megarad at room temperature; or
NR 204.07(6)(a)2.g.
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
NR 204.07(6)(a)2.h.
h. Maintain the temperature of the sludge at 70
° Celsius or higher for 30 minutes or longer; or
NR 204.07(6)(a)2.i.
i. Treat the sludge in a process that is equivalent to a process to further reduce pathogens, as approved by the department.
NR 204.07(6)(b)
(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:
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See PDF for table NR 204.07(6)(b)1.
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
NR 204.07(6)(b)2.a.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
NR 204.07(6)(b)2.b.
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
NR 204.07(6)(b)2.c.
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
NR 204.07(6)(b)2.d.
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
NR 204.07(6)(b)2.e.
e. Add sufficient lime to the sludge to raise the pH to 12 after 2 hours of contact; or
NR 204.07(6)(b)2.f.
f. Treat the sludge in a process that is equivalent to a process to significantly reduce pathogens, as approved by the department.
NR 204.07(7)
(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.
NR 204.07(7)(a)
(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
NR 204.07(7)(b)
(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
NR 204.07(7)(c)
(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
NR 204.07(7)(d)
(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
NR 204.07(7)(e)
(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
NR 204.07(7)(f)
(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
NR 204.07(7)(g)
(g) Dry the sludge to 75% total solids when the sludge contains no unstabilized solids from primary treatment; or
NR 204.07(7)(h)
(h) Dry the sludge to 90% total solids when the sludge contains unstabilized solids from primary treatment; or
NR 204.07(7)(i)
(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.
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See PDF for table NR 204.07(7)(j)1.
1. No significant amount of the sludge shall be present on the land surface within one hour after the sludge is injected.
NR 204.07(7)(j)2.
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
NR 204.07(7)(k)1.
1. Class B sludge shall be incorporated within 6 hours, unless otherwise specified by the department.
NR 204.07(7)(k)2.
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.
NR 204.07(8)(a)(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.
NR 204.07(8)(b)
(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.
NR 204.07(8)(c)
(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.
NR 204.07(8)(d)
(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.
NR 204.07(8)(e)
(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.
NR 204.07(8)(f)
(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.
NR 204.07 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96.
NR 204.08(1)
(1)
General. Sewage sludge may not be disposed of in a municipal solid waste landfill unless the landfill meets the requirements of
chs. NR 500 to
538 and is an approved facility as defined in s.
289.01 (3), Stats. Any facility accepting sewage sludge shall be approved by the department in writing to accept sewage sludge. Disposal of sewage sludge in a municipal solid waste landfill shall be in accordance with
ss. NR 506.13 and
506.14. Sewage sludge may not be disposed of in a surface disposal unit as defined in
s. NR 204.03 (63).
NR 204.08(2)
(2) Approval. The permittee shall obtain approval from the department prior to the disposal of sludge at a Wisconsin licensed landfill.
NR 204.08 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96; correction in (1) made under s. 13.93 (2m) (b) 7., Stats.,
Register, November, 1996, No. 491; correction in (1) made under s. 13.92 (4) (b) 7., Stats.,
Register February 2010 No. 650.
NR 204.09
NR 204.09 Alternative uses of sludge. Alternative uses of sludge such as land application on sod farms, nurseries, Christmas tree plantations, mined land reclamation sites, restoration of construction sites or other drastically disturbed sites, research plots, highway right-of-ways and medians, fallow lands, set-aside lands as covered by the Acreage Conservation Reserve (ACR) program, final cover at landfills and use in building materials may not be conducted unless department approval is obtained. Sludge used to generate energy may be approved on a case-by-case basis. Department approval will consider factors such as the nature of the alternative use proposed, sludge quality, number of applications that are proposed, loading of pollutants to the land, air and water, and the proximity to waters of the state. Proposals for alternative uses of sludge may include the land application site evaluation information as required by
s. NR 204.06 (6) and shall include any additional information that would allow the department to make a determination that the proposed use is beneficial and will not result in detrimental effects to the environment, public health or wildlife.
NR 204.09 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96.
NR 204.10(1)(a)(a) No person may construct or use any sludge storage facility without obtaining department approval. All facilities shall be designed and operated in accordance with the appropriate requirements in
ch. NR 110 and this chapter.
NR 204.10(1)(b)
(b) All municipal mechanical treatment plants shall have the ability to store sludge for 180 days. Storage shall be available by October 1, 1998 for facilities with a design flow of 1 million gallons per day or greater and by October 1, 2000 for facilities with a design flow of less than 1 million gallons per day. This storage requirement only applies to facilities which recycle sludge through land application or site reclamation projects. Wastewater treatment lagoons are also exempt from this requirement. An agreement with an approved municipal solid waste landfill, an incinerator, another permittee or other approved facility during winter months may be construed as acceptable storage, although a minimum of 15 days storage capacity shall be provided for emergency situations. Written documentation of an agreement shall be submitted to the department as evidence of compliance with this requirement. If a permittee does not currently have adequate storage, the permittee shall develop with the department a compliance schedule to obtain adequate sludge storage.
NR 204.10(2)
(2) Other storage facilities. The department may determine leasing to be an acceptable alternative to construction if the lease is for a minimum of 5 years with an option for another 5 years when the WPDES permit is reissued. If leasing is a temporary solution while a permittee is constructing long-term storage or developing an alternative long-term solution, the contract may be for less than 5 years. Sludge may be stored individually or in combination with other waste at sites such as, but not limited to, manure storage facilities and septage storage lagoons following the review and approval of the design and acceptance by the department of an operations report that shall demonstrate compliance with this chapter. This report shall contain at the minimum:
NR 204.10(2)(b)
(b) The type and volume of the storage facility, including construction details to demonstrate the integrity of the system and compliance with
ch. NR 110.
NR 204.10(2)(c)
(c) Sufficient site characteristics information to evaluate the environmental impact and suitability of the sludge storage location.
NR 204.10(2)(d)
(d) The name and address of the owners of the storage facility.
NR 204.10(2)(e)
(e) Any contractual agreements the permittee enters into with another party.
NR 204.10(2)(f)
(f) Sampling and analysis results of the combined wastes for nutrients and any other applicable parameters which demonstrate compliance with this chapter. Testing shall be conducted in accordance with requirements in the WPDES permit and this chapter.
NR 204.10(2)(g)
(g) The methods to be used for land application of the sludge or sludge mixture.
NR 204.10(2)(h)
(h) A list of the sites or fields where the stored sludge will be recycled, unless the sludge produced in the mixture meets the exceptional quality sludge criteria.
NR 204.10(3)
(3) Extended storage. If a person stores or treats a batch of sludge for longer than 2 years, the person shall retain the following information during the storage period:
NR 204.10(3)(b)
(b) The name and address of the person who owns the storage or treatment facility.
NR 204.10(3)(d)
(d) A brief explanation of why the sludge needs to remain in storage or treatment for longer than 2 years before it is land applied or disposed of.
NR 204.10(3)(e)
(e) The approximate time period when the sludge will be land applied or disposed of.
NR 204.10 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96.
NR 204.11(1)
(1)
General. The department may require the permittee to develop a sludge management plan, submit the plan to the department for approval and operate in compliance with the approved plan. The plan shall include a description of the facility's sludge management program and how the permittee plans to operate the facility in compliance with the requirements of this chapter.
NR 204.11(2)
(2) Imported sludge. Any person who is responsible for importing bulk exceptional quality sludge into this state shall submit a sludge management plan to the department. Bulk exceptional quality sludge may not be imported until the department has approved the sludge management plan.
NR 204.11 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96.
NR 204.12
NR 204.12 Grit and screenings disposal. All grit and screenings generated from a facility shall be disposed of at a solid waste disposal facility licensed under
chs. NR 500 to
538.
NR 204.12 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96; correction made under s.
13.92 (4) (b) 7., Stats.,
Register February 2010 No 650.
NR 204.13
NR 204.13 Sludge management program standards and requirements based upon federal regulations. NR 204.13(1)(1)
New federal regulations. In the event that new federal sludge standards or regulations are promulgated under section 405 of the clean water act, the permittee shall comply with the new sludge requirements by the dates established in the regulations, if required by federal law, even if the permit has not yet been modified to incorporate the new federal regulations. The requirement in this subsection shall be included as a permit condition in all permits that regulate sludge use and disposal under this chapter.
NR 204.13(2)
(2) State adoption. The department shall, as soon as possible, and in conformance with federal requirements, after the promulgation of any federal regulation establishing sludge management program standards or requirements as described in
sub. (1), adopt appropriate standards or requirements for permittees subject to this chapter and
ch. 283, Stats.
NR 204.13 History
History: Cr.
Register, December, 1995, No. 480, eff. 1-1-96; correction in (2) made under s. 13.93 (2m) (b) 7., Stats.,
Register, November, 1996, No. 491.
NR 204.14(1)
(1)
General. The department shall prepare a fact sheet or briefing memo for any generator applying for a permit under
s. NR 204.05. Information specified in this section shall be included in the fact sheet or briefing memo sent to the applicant.
NR 204.14(2)
(2) Information included. The fact sheet or briefing memo shall include when applicable, the following:
NR 204.14(2)(a)
(a) A brief description of the type of facility or activity which is the subject of the draft permit.
NR 204.14(2)(b)
(b) The type and quantity of sludge which is or will be treated, stored, disposed of, used or recycled.
