Tenn. Comp. R. & Regs. 0400-40-15-.04

Current through June 26, 2024

Section 0400-40-15-.04 - PATHOGENS AND VECTOR ATTRACTION REDUCTION [40 CFR 503 SUBPART D]

(1) Scope [ 40 CFR 503.30 ]

(a) This rule contains the requirements for biosolids and sewage sludge to be classified either Class A or Class B with respect to pathogens.

(b) This rule contains the site restrictions for land on which Class B biosolids are applied.

(c) This rule contains alternative vector attraction reduction requirements for biosolids that are applied to the land.

(2) Special definitions [ 40 CFR 503.31 ]

"Aerobic digestion" is the biochemical decomposition of organic matter in sewage sludge into carbon dioxide and water by microorganisms in the presence of air.

"Anaerobic digestion" is the biochemical decomposition of organic matter in sewage sludge into methane gas and carbon dioxide by microorganisms in the absence of air.

"Density of microorganisms" is the number of microorganisms per unit mass of total solids (dry weight) in the biosolids or sewage sludge.

"Land with a high potential for public exposure" is land that the public uses frequently. This includes, but is not limited to, a public contact site and a reclamation site located in a populated area (e.g., a construction site located in a city).

"Land with a low potential for public exposure" is land that the public uses infrequently. This includes, but is not limited to, agricultural land, forest, and a reclamation site located in an unpopulated area (e.g., a strip mine located in a rural area).

"Pathogenic organisms" are disease-causing organisms. These include, but are not limited to, certain bacteria, protozoa, viruses, and viable helminth ova.

"pH" means the logarithm of the reciprocal of the hydrogen ion concentration measured at 25° Centigrade or measured at another temperature and then converted to an equivalent value at 25° Centigrade.

"Specific oxygen uptake rate" or "SOUR" is the mass of oxygen consumed per unit time per unit mass of total solids (dry weight basis) in the biosolids or sewage sludge.

"Total solids" are the materials in biosolids or sewage sludge that remain as residue when they are dried at 103° to 105° Celsius.

"Unstabilized solids" are organic materials in biosolids or sewage sludge that have not been treated in either an aerobic or anaerobic treatment process.

"Vector attraction" is the characteristic of biosolids or sewage sludge that attracts rodents, flies, mosquitoes, or other organisms capable of transporting infectious agents.

"Volatile solids" is the amount of the total solids in biosolids or sewage sludge lost when they are combusted at 550° Celsius in the presence of excess air.

(3) Pathogens [ 40 CFR 503.32 ]

(a) Biosolids-Class A.

1. The requirement in part 2 of this subparagraph and the requirements in either parts 3, 4, 5, 6, 7, or 8 of this subparagraph shall be met for a biosolids to be classified Class A with respect to pathogens.

2. The Class A pathogen requirements in parts 3 through 8 of this subparagraph shall be met either prior to meeting or at the same time the vector attraction reduction requirements in paragraph (4) of this rule, except the vector attraction reduction requirements in parts (4)(b)6 through 8 of this rule, are met.

3. Class A-Alternative 1

(i) Either the density of fecal coliform in the biosolids shall be less than 1000 Most Probable Number per gram of total solids (dry weight basis), or the density of Salmonella sp. bacteria in the biosolids shall be less than three Most Probable Number per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02.

(ii) The temperature of the biosolids that are applied or disposed shall be maintained at a specific value for a period of time.

(I) When the percent solids of the biosolids are seven percent or higher, the temperature of the biosolids shall be 50° Celsius or higher; the time period shall be 20 minutes or longer; and the temperature and time period shall be determined using Equation (1), except when small particles of sewage sludge are heated by either warmed gases or an immiscible liquid.

Equation (1)

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(II) When the percent solids of the biosolids are seven percent or higher and small particles of sewage sludge are heated by either warmed gases or an immiscible liquid, the temperature of the biosolids shall be 50° Celsius or higher; the time period shall be 15 seconds or longer; and the temperature and time period shall be determined using Equation (1).

(III) When the percent solids of the biosolids are less than seven percent and the time period is at least 15 seconds, but less than 30 minutes, the temperature and time period shall be determined using Equation (1).

(IV) When the percent solids of the biosolids are less than seven percent; the temperature of the biosolids are 50° Celsius or higher; and the time period is 30 minutes or longer, the temperature and time period shall be determined using Equation (2).

Equation (2)

Click to view Image

4. Class A-Alternative 2

(ii)

(I) The pH of the biosolids that are applied or disposed shall be raised to above 12 and shall remain above 12 for 72 hours.

(II) The temperature of the biosolids shall be above 52° Celsius for 12 hours or longer during the period that the pH of the biosolids is above 12.

(III) At the end of the 72 hour period during which the pH of the biosolids are above 12, the biosolids shall be air dried to achieve a percent solids in the biosolids greater than 50 percent.

5. Class A-Alternative 3

(i) Either the density of fecal coliform in the biosolids shall be less than 1000 Most Probable Number per gram of total solids (dry weight basis), or the density of Salmonella sp. bacteria in biosolids shall be less than three Most Probable Number per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02.

(ii)

(I) The biosolids shall be analyzed prior to pathogen treatment to determine whether the biosolids contains enteric viruses.

(II) When the density of enteric viruses in the biosolids prior to pathogen treatment is less than one Plaque-Forming Unit per four grams of total solids (dry weight basis), the biosolids are Class A with respect to enteric viruses until the next monitoring episode for the biosolids.

(III) When the density of enteric viruses in the biosolids prior to pathogen treatment is equal to or greater than one Plaque-Forming Unit per four grams of total solids (dry weight basis), the biosolids are Class A with respect to enteric viruses when the density of enteric viruses in the biosolids after pathogen treatment is less than one Plaque-Forming Unit per four grams of total solids (dry weight basis) and when the values or ranges of values for the operating parameters for the pathogen treatment process that produces the biosolids that meet the enteric virus density requirement are documented.

(IV) After the enteric virus reduction in item III of this subpart is demonstrated for the pathogen treatment process, the biosolids continue to be Class A with respect to enteric viruses when the values for the pathogen treatment process operating parameters are consistent with the values or ranges of values documented in item III of this subpart.

(iii)

(I) The biosolids shall be analyzed prior to pathogen treatment to determine whether the biosolids contain viable helminth ova.

(II) When the density of viable helminth ova in the biosolids prior to pathogen treatment is less than one per four grams of total solids (dry weight basis), the biosolids are Class A with respect to viable helminth ova until the next monitoring episode for the biosolids.

(III) When the density of viable helminth ova in the biosolids prior to pathogen treatment is equal to or greater than one per four grams of total solids (dry weight basis), the biosolids are Class A with respect to viable helminth ova when the density of viable helminth ova in the biosolids after pathogen treatment is less than one per four grams of total solids (dry weight basis) and when the values or ranges of values for the operating parameters for the pathogen treatment process that produces the biosolids that meet the viable helminth ova density requirement are documented.

(IV) After the viable helminth ova reduction in item III of this subpart is demonstrated for the pathogen treatment process, the biosolids continue to be Class A with respect to viable helminth ova when the values for the pathogen treatment process operating parameters are consistent with the values or ranges of values documented item III of this subpart.

(iv) The use of Alternative 3 for Class A pathogen reduction requires prior written approval from the State Biosolids Coordinator.

6. Class A-Alternative 4

(ii) The density of enteric viruses in the biosolids shall be less than one Plaque-Forming Unit per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02, unless otherwise specified by the State Biosolids Coordinator.

(iii) The density of viable helminth ova in the biosolids shall be less than one per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02, unless otherwise specified by the State Biosolids Coordinator.

(iv) The use of Alternative 4 for Class A pathogen reduction requires prior written approval from the State Biosolids Coordinator.

7. Class A-Alternative 5

(i) Either the density of fecal coliform in the biosolids shall be less than 1000 Most Probable Number per gram of total solids (dry weight basis), or the density of Salmonella, sp. bacteria in the biosolids shall be less than three Most Probable Number per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02.

(ii) Biosolids that are applied or disposed shall be treated in one of the Processes to Further Reduce Pathogens described in paragraph (5) of this rule.

8. Class A-Alternative 6

(i) Either the density of fecal coliform in the biosolids shall be less than 1000 Most Probable Number per gram of total solids (dry weight basis), or the density of Salmonella, sp. bacteria in the biosolids shall be less than three Most Probable Number per four grams of total solids (dry weight basis) at the time the biosolids are applied or disposed; at the time the biosolids are prepared for sale or given away in a bag or other container for application to the land; or at the time the biosolids or material derived from biosolids are prepared to meet the requirements in subparagraph (1)(b) of Rule 0400-40-15-.02.

(ii) Biosolids that are applied or disposed shall be treated in a process that is equivalent to a Process to Further Reduce Pathogens as determined by EPA Region 4.

(b) Biosolids-Class B.

(i) The requirements in either part 2, 3, or 4 of this subparagraph shall be met for biosolids to be classified Class B with respect to pathogens.

(ii) The site restrictions in part 5 of this subparagraph shall be met when biosolids that meet the Class B pathogen requirements in part 2, 3, or 4 of this subparagraph are applied to the land.

2. Class B-Alternative 1

(i) Seven representative samples of the biosolids that are applied or disposed shall be collected.

(ii) The geometric mean of the density of fecal coliform in the samples collected in subpart (i) of this part shall be less than either 2,000,000 Most Probable Number per gram of total solids (dry weight basis) or 2,000,000 Colony Forming Units per gram of total solids (dry weight basis).

3. Class B-Alternative 2

Biosolids that are applied or disposed shall be treated in one of the Processes to Significantly Reduce Pathogens described in paragraph (5) of this rule.

4. Class B-Alternative 3

Biosolids that are applied or disposed shall be treated in a process that is equivalent to a Process to Significantly Reduce Pathogens, as determined by EPA Region 4.

5. Site restrictions

(i) Food crops with harvested parts that touch the biosolids/soil mixture and are totally above the land surface shall not be harvested for 14 months after application of biosolids.

(ii) Food crops with harvested parts below the surface of the land shall not be harvested for 20 months after application of biosolids when the biosolids remain on the land surface for four months or longer prior to incorporation into the soil.

(iii) Food crops with harvested parts below the surface of the land shall not be harvested for 38 months after application of biosolids when the biosolids remain on the land surface for less than four months prior to incorporation into the soil.

(iv) Food crops, feed crops, and fiber crops shall not be harvested for 30 days after application of biosolids.

(v) Animals shall not be grazed on the land for 30 days after application of biosolids.

(vi) Turf grown on land where biosolids are applied shall not be harvested for one year after application of the biosolids when the harvested turf is placed on either land with a high potential for public exposure or a lawn, unless otherwise specified by the State Biosolids Coordinator.

(vii) Public access to land with a high potential for public exposure shall be restricted for one year after application of biosolids.

(viii) Public access to land with a low potential for public exposure shall be restricted for 30 days after application of biosolids.

(4) Vector attraction reduction [ 40 CFR 503.33 ]

(a)

1. One of the vector attraction reduction requirements in parts (b)1 through 10 of this paragraph shall be met when bulk biosolids are applied to agricultural land, forest, a public contact site, or a reclamation site.

2. One of the vector attraction reduction requirements in parts (b)1 through 8 of this paragraph shall be met when bulk biosolids are applied to a lawn or a home garden.

3. One of the vector attraction reduction requirements in parts (b)1 through 8 of this paragraph shall be met when biosolids are sold or given away in a bag or other container for application to the land.

(b)

1. The mass of volatile solids in the biosolids shall be reduced by a minimum of 38 percent (see calculation procedures in "Environmental Regulations and Technology-Control of Pathogens and Vector Attraction in Sewage Sludge," EPA-625/R-92/013, 1992, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268).

2. When the 38 percent volatile solids reduction requirement in part 1 of this subparagraph cannot be met for an anaerobically digested biosolids, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids anaerobically in the laboratory in a bench-scale unit for 40 additional days at a temperature between 30 and 37° Celsius. When at the end of the 40 days, the volatile solids in the biosolids at the beginning of that period are reduced by less than 17 percent, vector attraction reduction is achieved.

3. When the 38 percent volatile solids reduction requirement in part 1 of this subparagraph cannot be met for an aerobically digested biosolids, vector attraction reduction can be demonstrated by digesting a portion of the previously digested biosolids that have a percent solids of two percent or less aerobically in the laboratory in a bench-scale unit for 30 additional days at 20° Celsius. When at the end of the 30 days, the volatile solids in the biosolids at the beginning of that period are reduced by less than 15 percent, vector attraction reduction is achieved.

4. The specific oxygen uptake rate (SOUR) for biosolids treated in an aerobic process shall be equal to or less than 1.5 milligrams of oxygen per hour per gram of total solids (dry weight basis) at a temperature of 20° Celsius.

5. Biosolids shall be treated in an aerobic process for 14 days or longer. During that time, the temperature of the biosolids shall be higher than 40° Celsius and the average temperature of the biosolids shall be higher than 45° Celsius.

6. The pH of biosolids shall be raised to 12 or higher by the addition of alkaline material and, without the addition of more alkaline material, shall remain at 12 or higher for two hours and then at 11.5 or higher for an additional 22 hours.

7. The percent solids of biosolids that do not contain unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 75 percent based on the moisture content and total solids prior to mixing with other materials.

8. The percent solids of biosolids that contain unstabilized solids generated in a primary wastewater treatment process shall be equal to or greater than 90 percent based on the moisture content and total solids prior to mixing with other materials.

(i) Biosolids shall be injected below the surface of the land.

(ii) No significant amount of the biosolids shall be present on the land surface within one hour after the biosolids are injected.

(iii) When the biosolids that are injected below the surface of the land are Class A with respect to pathogens, the biosolids shall be injected below the land surface within eight hours after being discharged from the pathogen treatment process.

10.

(i) Biosolids applied to the land surface shall be incorporated into the soil within six hours after application to or placement on the land, unless otherwise specified by the State Biosolids Coordinator.

(ii) When biosolids that are incorporated into the soil are Class A with respect to pathogens, the biosolids shall be applied to or placed on the land within eight hours after being discharged from the pathogen treatment process.

(5) Pathogen Treatment Processes [Appendix B to Part 503]

(a) Processes To Significantly Reduce Pathogens (PSRP).

1. Aerobic digestion-Sewage sludge or biosolids are agitated with air or oxygen to maintain aerobic conditions for a specific mean cell residence time at a specific temperature. Values for the mean cell residence time and temperature shall be between 40 days at 20° Celsius and 60 days at 15° Celsius.

2. Air drying-Sewage sludge or biosolids are dried on sand beds or on paved or unpaved basins. The sewage sludge or biosolids dry for a minimum of three months. During two of the three months, the ambient average daily temperature is above 0° Celsius.

3. Anaerobic digestion-Sewage sludge or biosolids are treated 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° Celsius and 60 days at 20° Celsius.

4. Composting-Using either the within-vessel, static aerated pile, or windrow composting methods, the temperature of the sewage sludge or biosolids is raised to 40° Celsius or higher and remains at 40° Celsius or higher for five days. For four hours during the five days, the temperature in the compost pile exceeds 55° Celsius. Passively aerated static pile composting is not an acceptable PSRP.

5. Lime stabilization-Sufficient lime is added to the sewage sludge or biosolids to raise the pH of the sewage sludge or biosolids to 12 after two hours of contact.

(b) Processes to Further Reduce Pathogens (PFRP).

1. Composting-Using either the within-vessel composting method or the static aerated pile composting method, the temperature of the sewage sludge or biosolids is maintained at 55° Celsius or higher for three days. Passively aerated static pile composting is not an acceptable PSRP.

Using the windrow composting method, the temperature of the sewage sludge or biosolids is maintained at 55° or higher for 15 days or longer. During the period when the compost is maintained at 55° or higher, there shall be a minimum of five turnings of the windrow.

2. Heat drying-Sewage sludge or biosolids are dried by direct or indirect contact with hot gases to reduce the moisture content of the sewage sludge or biosolids to 10 percent or lower. Either the temperature of the biosolids particles exceeds 80° Celsius or the wet bulb temperature of the gas in contact with the biosolids as the biosolids leaves the dryer exceeds 80° Celsius.

3. Heat treatment-Liquid sewage sludge or biosolids are heated to a temperature of 180° Celsius or higher for 30 minutes.

4. Thermophilic aerobic digestion-Liquid sewage sludge or biosolids are agitated with air or oxygen to maintain aerobic conditions and the mean cell residence time of the sewage sludge or biosolids is 10 days at 55 to 60° Celsius.

5. Beta ray irradiation-Sewage sludge or biosolids are irradiated with beta rays from an accelerator at dosages of at least 1.0 megarad at room temperature (ca. 20° Celsius).

6. Gamma ray irradiation-Sewage sludge or biosolids are irradiated with gamma rays from certain isotopes, such as ⁶⁰ Cobalt and ¹³⁷ Cesium, at dosages of at least 1.0 megarad at room temperature (ca. 20° Celsius).

7. Pasteurization-The temperature of the sewage sludge or biosolids is maintained at 70° Celsius or higher for 30 minutes or longer.

Tenn. Comp. R. & Regs. 0400-40-15-.04

Original rule filed April 1, 2013; effective June 30, 2013.

Authority: T.C.A. §§ 69-3-101 et seq. and 4-5-201 et seq.