C.M.R. 06, 096, ch. 419, app 096-419-B
1.Special Definitions. For the purposes of this chapter, the following terms have the following meanings:
A. Aerobic digestion is the biochemical decomposition of organic matter in sewage sludge into carbon dioxide and water by microorganisms in the presence of air.
B. 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.
C. Density of microorganisms is the number of microorganisms per unit mass of total solids (dry weight) in the sewage sludge.
D. Land with a high potential for public exposure is land that the public uses frequently. This includes, but is not limited to, playgrounds, public parks, athletic fields, cemeteries, plant nurseries, construction sites in urban areas, and turf farms.
E. Land with a low potential for public exposure is land that the public uses infrequently. This includes, but is not limited to, agricultural land, forests, and/or reclamation sites located in an unpopulated or rural area; remote lands; or securely fenced land.
F. Pathogenic organisms are disease-causing organisms. These include, but are not limited to, certain bacteria, protozoa, viruses, and viable helminth ova.
G. pH means the logarithm of the reciprocal of the hydrogen ion concentration, corrected to a standard temperature of 25 degrees Celsius.
H. Specific oxygen uptake rate (SOUR) is the mass of oxygen consumed per unit time per unit mass of total solids (dry weight basis) in the sewage sludge.
I. Total solids are the materials in sewage sludge that remain as residue when the sewage sludge is dried at 103 to 105 degrees Celsius.
J. Unstabilized solids are organic materials in sewage sludge that have not been treated in either an aerobic or anaerobic treatment process.
K. Vector attraction is the characteristic of sewage sludge that attracts rodents, flies, mosquitoes, or other organisms capable of transporting infectious agents.
L. Volatile solids is the amount of the total solids in sewage sludge lost when the sewage sludge is combusted at 550 degrees Celsius in the presence of excess air.
2.Class A Pathogen Reduction Process Standards. Class A pathogen reduction standards must be met through one of the following processes:
A.Composting. Through the process of composting, the temperature of the residual is maintained at 55 degrees Celsius or higher for three consecutive days. For windrow systems, this standard is presumed to be met if the residual is generally maintained at 55 degrees or higher for 15 days or longer, and during the period when the compost is maintained at 55 degrees or higher, there is a minimum of five turnings of the compost pile.
B.Thermophilic Aerobic Digestion. Liquid residual is agitated with air or oxygen to maintain aerobic conditions and the mean cell residence time of the residual is 10 days at 55 to 60 degrees Celsius.
C.Beta Ray Irradiation. Residual is irradiated with beta rays from an accelerator at dosages of at least 1.0 megarad at room temperature (ca 20 degrees Celsius).
D.Gamma Ray Irradiation. Residual is irradiated with gamma rays from certain isotopes, such as 60Cobalt and 137Cesium, at dosages of at least 1.0 megarad at room temperature (ca 20 degrees Celsius).
E.Pasteurization. The temperature of the residual is maintained at 70 degrees Celsius or higher for 30 minutes or longer.
F.Heat Drying. Residual is dried by direct or indirect contact with hot gases to reduce the moisture content of the residual to 10 percent or lower. Either the temperature of the residual particles exceeds 80 degrees Celsius or the wet bulb temperature of the gas in contact with the residual as the residual leaves the dryer exceeds 80 degrees Celsius.
G.Heat Treatment. Liquid residual is heated to a temperature of 180 degrees Celsius or higher for 30 minutes.
H.Time and Temperature. The temperature of the residual must be maintained at a specific value for a period of time as specified in one of the following:
(1) When the percent solids of the residual is seven percent or higher, the temperature of the residual must be 50 degrees Celsius or higher; the time period must be 20 minutes or longer; and the temperature and time period must be determined the following equation (419.4), except when small particles of residual are heated by either warmed gases or an immiscible liquid:
EQUATION (419.4):
D = (131,700,000) ÷ 100.1400t
Where: D=time in days
t=temperature in degrees Celsius.
(2) When the percent solids of the residual is seven percent or higher and small particles of residual are heated by either warmed gases or an immiscible liquid, the temperature of the residual must be 50 degrees Celsius or higher; the time period must be 15 seconds or longer; and the temperature and time period must be determined using equation (419.4).
(3) When the percent solids of the residual is less than seven percent and the time period is at least 15 seconds, but less than 30 minutes, the temperature and time period must be determined using equation (419.4).
(4) When the percent solids of the residual is less than seven percent; the temperature of the residual is 50 degrees Celsius or higher; and the time period is 30 minutes or longer, the temperature and time period must be determined by using equation (419.5).
EQUATION (419.5)
D=50,070,000 ÷ 100.1400t
Where: D=time in days
t=temperature in degrees Celsius.
I.Alkaline Stabilization. The pH of the residual must be raised to above 12 and must remain above 12 for 72 hours. The temperature of the residual must be above 52 degrees Celsius for 12 hours or longer during the period that the pH of the residual is above 12. At the end of the 72 hour period during which the pH of the residual is above 12, the residual must be air dried to achieve a percent solids in the residual greater than 50 percent.
J.Other. Other methods for the treatment of residuals will be approved on a case by case basis, when the generator demonstrates, at a minimum, that the proposed process can meet the following standards, and under what operating conditions the following standards are met. Once approved, the process must be operated under the conditions that are established by the Department as meeting, at a minimum, the following Class A pathogen reduction standards.
(1) The density of Salmonella sp. bacteria in the residual must be less than three Most Probable Number per four grams of total solids (dry weight basis).
(2) The density of fecal coliform in the residual is shown to be less than 1000 Most Probable Number per gram of total solids (dry weight basis).
(3) The density of enteric viruses in the residual after pathogen treatment is less than one Plaque-forming Unit per four grams of total solids (dry weight basis).
(4) The density of viable helminth ova in the residual after pathogen treatment is less than one per four grams of total solids (dry weight basis).
3.Class B Pathogen Reduction Process Standards. Class B pathogen reduction standards must be met through one of the following processes:
A.Alkaline Stabilization. Sufficient alkali material, such as lime, is added to the residual to raise the pH of the residual to 12 after two hours of contact;
B.Aerobic Digestion. Residual is 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 must be between 40 days at 20 degrees Celsius and 60 days at 15 degrees Celsius;
C.Air Drying. Residual is dried on sand beds or on paved or unpaved basins. The residual dries for a minimum of three months. During two of the three months, the ambient average daily temperature is above zero degrees Celsius;
D.Anaerobic Digestion. Residual is 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 must be between 15 days at 35 to 55 degrees Celsius and 60 days at 20 degrees Celsius;
E.Composting. In a compost system the minimum temperature of all the residual is 40 degrees Celsius or higher for five days. For four hours during the five days, the temperature in the compost pile exceeds 55 degrees Celsius;
F.Test Out. Seven samples of the residual must 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); or
G.Other. Other methods for the treatment of residuals will be approved on a case by case basis, when the generator demonstrates that the proposed process meets the standards in section 4 of this chapter and 06-096 CMR ch. 400, sections 3 and 4.
4.Class A Vector Attraction Reduction Standards. Class A vector attraction reduction standard must be met through one of the following process:
A. In an aerobic or anaerobic digestion process, the mass of volatile solids in the residual must 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, US. Environmental Protection Agency, Cincinnati, Ohio 45268). This standard does not apply to a composting process;
B. When the 38 percent volatile solids reduction requirement in Appendix B.4.A (above) cannot be met for an anaerobically digested sewage sludge, vector attraction reduction can be demonstrated by digesting a portion of the previously digested sewage sludge anaerobically in the laboratory in a bench-scale unit for 40 additional days at a temperature between 30 and 37 degrees Celsius. When at the end of the 40 days the volatile solids in the sewage sludge at the beginning of that period is reduced by less than 17 percent, vector attraction reduction is achieved;
C. When the 38 percent volatile solids reduction requirement in Appendix B.4.A (above) cannot be met for an aerobically digested sewage sludge, vector attraction reduction can be demonstrated by digesting a portion of the previously digested sewage sludge that has a percent solids of two percent or less aerobically in the laboratory in a bench-scale unit for 30 additional days at 20 degrees Celsius. When at the end of the 30 days, the volatile solids in the sewage sludge at the beginning of that period is reduced by less than 15 percent, vector attraction reduction is achieved;
D. The specific oxygen uptake rate (SOUR) for residual treated in an aerobic digestion process must be equal to or less than 1.5 milligrams of oxygen per hour per gram of total solid (dry weight basis) at a temperature of 20 degrees Celsius. This standard does not apply to a composting process;
E. Residual must be treated by composting or in another aerobic process for 14 days or longer. During that time, the temperature of the residual must be higher than 40 degrees Celsius and the average temperature of the residual must be higher than 45 degrees Celsius;
F. The pH of residual must be raised to 12 or higher by alkali addition and, without the addition of more alkali, must remain at 12 or higher for two hours and then at 11.5 or higher for an additional 22 hours;
NOTE: The pH does not have to be 11.5 at the time of application.
G. The percent solids of residual that does not contain unstabilized solids generated in primary wastewater treatment process must be equal to or greater than 75 percent based on the moisture content and total solids prior to mixing with other materials;
H. The percent solids of residual that contains unstabilized solid generated in a primary wastewater treatment process must be equal to or greater than 90 percent based on the moisture content and total solids prior to mixing with other materials; or
I. Other methods for the treatment of residuals will be approved on a case by case basis, when the generator demonstrates that the proposed process meets the standards in section 4 of this chapter and 06-096 CMR ch. 400, sections 3 and 4.
5.Class B Vector Attraction Reduction Standards. Class B vector attraction reduction standards must be met through one of the following residual handling practices:
A. Residual must be injected below the surface of the land. No significant amount of the residual must be present on the land surface within one hour after the residual is injected. When the residual that is injected below the surface of the land is Class A with respect to pathogens, the residual must be injected below the land surface within eight hours after being discharged from the pathogen treatment process;
B. Residual applied to the land surface must be incorporated into the soil within six hours after application. When the residual that is incorporated into the soil is Class A with respect to pathogens, the residual must be applied to or placed on the land within eight hours after being discharged from the pathogen treatment process;
C. The pH of residual must be raised to 12 or higher by alkali addition and, without the addition of more alkali, must remain at 12 or higher for two hours and then at 11.5 or higher for an additional 22 hours; or
D. Other methods for the treatment of residuals will be approved on a case by case basis, when the generator demonstrates that the proposed process meets the standards in section 4 of this chapter and 06-096 CMR ch. 400, sections 3 and 4.
C.M.R. 06, 096, ch. 419, app 096-419-B