Chapter NR 204

NR 204.07(3)(n)6. 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.

NR 204.07 Note Note: 1 microcurie = 10-6 curies, 1 picocurie = 10-12 curies

NR 204.07(3)(n)7. 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.

NR 204.07(3)(o) (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.

NR 204.07(4) (4) Sludge quality (standards and processes).

NR 204.07(4)(a) (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.

NR 204.07(4)(b) (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.

NR 204.07(4)(c) (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).

NR 204.07(5) (5) Metal concentrations.

NR 204.07(5)(a) (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.

NR 204.07(5)(b) (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.

NR 204.07(5)(c) (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).

NR 204.07 Note Note: The department strongly encourages permittees to produce sludge which meets the high quality pollutant concentration limits set in Table 3.

NR 204.07(5)(d) (d)

NR 204.07(5)(d)1. 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:

NR 204.07(5)(d)2. 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:

NR 204.07(5)(d)2.a. a. The name and address of the permittee who generated the sludge.

NR 204.07(5)(d)2.b. b. A statement that prohibits the use of the sludge except in accordance with the instructions on the label or information sheet.

NR 204.07(5)(d)2.c. 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.

NR 204.07(5)(d)2.d. d. The percentage content of nitrogen, phosphorus and potassium present in the sludge.

NR 204.07(6) (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).

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:

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(6)(a)2. 2. ‘Pathogen treatment processes.’

NR 204.07(6)(a)2.a. 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

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:

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. 2. ‘Pathogen treatment processes.’

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.

NR 204.07(7)(j) (j) Injection below the soil surface

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) (k) Incorporation

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) (8) Application rates.

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 NR 204.08 Landfill disposal.

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 NR 204.10 Storage facilities.

NR 204.10(1) (1) General.

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)(a) (a) The location of the storage facility.

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: