Attch. 22 MX- Norma004_Semarnat_2002_english version.pdf

18 OFFICIAL GAZETTE Friday, August 15, 2003

SECRETARIAT OF ENVIRONMENT

AND NATURAL RESOURCES

Official Mexican Standard NOM-004-SEMARNAT-2002, Environmental protection - Sludge and biosolids - Specifications and maximum permissible limits of pollutants for their use and final disposal.

In the margin a seal with the National Coat of Arms, which reads: United Mexican States – Secretariat of Environment and Natural Resources.

OFFICIAL MEXICAN STANDARD NOM-004-SEMARNAT-2002, ENVIRONMENTAL PROTECTION - SLUDGE AND BIOSOLIDS - SPECIFICATIONS AND MAXIMUM PERMISSIBLE LIMITS OF POLLUTANTS FOR THEIR USE AND FINAL

DISPOSAL.

CASSIO LUISELLI FERNANDEZ, Undersecretary of Environmental Promotion and Regulations of the Secretariat of the Environment and Natural Resources and President of the National Consultative Committee of Standardization of the Environment and Natural Resources, based on the provisions of Articles 32 Bis sections I, II, IV, V and 39 sections I, VIII and XXI of the Organic Law of the Federal Public Administration; 4 of the Federal Law of Administrative Procedure; 8 section V of the Internal Regulations of the Secretariat of the Environment and Natural Resources; 5o. V and VI, 36, 37, 37 Bis, 119, 139 of the General Law of Ecological Balance and Environmental Protection; 5o. fraction VI and 6o. of the Regulation of the General Law of Ecological Balance and Environmental Protection on Environmental Impact; 38 fraction II, 40 fractions I and X; 41, 43, 44 and 47 fraction IV of the Federal Law on Metrology and Standardization; 28, 31 fraction II, 33 and 34 of its Regulation, issues the following Official Mexican Standard NOM-004-SEMARNAT-2002, Environmental Protection - Sludge and biosolids. Sludge and biosolids - Specifications and maximum permissible limits of pollutants for their use and final disposal, and

WHEREAS

In compliance with the provisions of section I of article 47 of the Federal Law on Metrology and Standardization, on February 18, 2002, the Official Mexican Standard PROY-NOM-004-ECOL-2001 was published in the Official Gazette of the Federation as a draft, Environmental protection - Sludge and biosolids

- Specifications and maximum permissible limits of pollutants for their use and final disposal, so that within 60 calendar days following its publication, interested parties could submit their comments to the National Consultative Committee for Standardization of the Environment and Natural Resources, located at 4209 Adolfo Ruiz Cortines Boulevard, 5th floor, Mexico City, Mexico., colonia Jardines en la Montaña, postal code 14210, Delegación Tlalpan, Distrito Federal (Mexico City) or sent to the e-mail or fax indicated for that purpose. During the aforementioned period, the corresponding Regulatory Impact Statement was available to the general public for consultation at the aforementioned address, in accordance with article 47 section I of the aforementioned ordinance.

Within the aforementioned 60-day period, the interested parties submitted their comments to the project in question, which were analyzed by the aforementioned Committee, making the appropriate modifications to the same. The Secretary of the Environment and Natural Resources published the responses to the comments received in the Official Gazette of the Federation on June 18, 2003.

Having complied with the procedure established in the Federal Law on Metrology and Standardization, the National Consultative Committee of Standardization of the Environment and Natural Resources, in ordinary session on September 24, 2002, approved the Official Mexican Standard NOM-004-SEMARNAT-2002, Environmental Protection-Sludge and biosolids-Specifications and maximum permissible limits of pollutants for their use and final disposal. In view of the foregoing, the following is hereby issued:

OFFICIAL MEXICAN STANDARD NOM-004-SEMARNAT-2002, ENVIRONMENTAL PROTECTION-

SLUDGES AND BIOSOLIDS-SPECIFICATIONS

AND BIOSOLIDS-SPECIFICATIONS AND MAXIMUM PERMISSIBLE LIMITS OF POLLUTANTS FOR

THEIR USE AND FINAL DISPOSAL.

CONTENTS

0. Introduction

1. Objective and scope of application

2. References

Friday, August 15, 2003 OFFICIAL GAZETTE 19

3. Definitions

4. Specifications

5. Sampling and test methods

6. Conformity assessment

7. Degree of concordance with international standards and guidelines

8. Bibliography

9. Compliance with this Standard

Attachments

I Options for vector attraction reduction

II Sludge and biosolids sampling method

III Method for the quantification of fecal coliforms in sludge and biosolids

IV Method for the quantification of Salmonella spp. in sludge and biosolids

V Method for the quantification of helminth eggs in sludge and biosolids

VI Method for the quantification of heavy metals in biosolids

VIl Contents of the sludge and biosolids monitoring logbook.

0. Introduction

In the activities of cleaning urban or municipal sewage systems, as well as in the operation of drinking water treatment plants and wastewater treatment plants, volumes of sludge are generated, which, if not properly disposed of, contribute significantly to the pollution of the atmosphere, national waters and soils, affecting the ecosystems of the area where they are deposited.

It has been considered that sludge, due to its own characteristics or those acquired after a stabilization process, can be susceptible to use as long as it complies with the maximum permissible limits of contaminants established in this Official Mexican Standard or, if applicable, it is definitively disposed of as non-hazardous waste;

to attenuate its contaminating effects on the environment and protect the population in general.

1. Objective and field of application

1.1 Objective

This Official Mexican Standard establishes the specifications and maximum permissible limits of contaminants in sludge and biosolids from the cleaning of urban or municipal sewage systems, water treatment plants and wastewater treatment plants, in order to enable their use or final disposal and protect the environment and human health.

1.2 Scope of application

It is mandatory for all individuals and companies that generate sludge and biosolids from the cleaning of urban or municipal sewage systems, drinking water treatment plants and wastewater treatment plants.

2. References

Non-hazardous waste certificate, formerly procedure INE-04-007, modified its homoclave code on May 29, 2003, by means of the agreement by which all the procedures and services registered in the Federal Registry of Procedures and Services applied by the Secretariat of Environment and Natural Resources, now procedure SEMARNAT-07-007, are made public.

NMX-B-231-1990, Screens for the classification of granular materials, published in the Official Gazette of the Federation on December 27, 1990.

3. Definitions

For the purposes of this Official Mexican Standard, the following definitions are established:

3.1 Wastewater

Waters of varied composition from discharges of municipal, industrial, commercial, service, agricultural, 20 OFFICIAL GAZETTE Friday, August 15, 2003 livestock, domestic uses, including subdivisions and in general from any other use, as well as the mixture of them.

3.2 Storage

The action of keeping sludge and biosolids in a place until they are used or disposed of.

3.3 Use

The use of biosolids as soil improvers or conditioners due to their organic matter and nutrient content, or in any activity that represents a benefit.

3.4 Vector attraction

The characteristic of sludge and biosolids to attract vectors such as rodents, flies, mosquitoes or other organisms capable of carrying infectious agents.

3.5 Biosolids

Sludge that has been subjected to stabilization processes and that, due to its organic matter content, nutrients and characteristics acquired after stabilization, can be susceptible to utilization.

3.6 Fecal coliforms

Pathogenic bacteria present in the intestine of warm-blooded animals and humans. Non-sporulated Gram-negative short bacilli, also known as thermotolerant coliforms. They can be identified by their tolerance to temperatures of 44°C-45°C. They have the ability to ferment lactose at temperatures of 44.5°C. They include the genus Escherichia and some species of Klebsiella.

3.7 Desludging

The action of removing solids from urban or municipal sewage systems, not including those from dams or regulating vessels.

3.8 Aerobic digestion

The biochemical transformation of organic matter present in sludge, which is transformed into carbon dioxide and water by microorganisms in the presence of oxygen.

3.9 Anaerobic digestion

This is the biochemical transformation of the organic matter present in the sludge, which is transformed into methane gas and carbon dioxide and water by microorganisms in the absence of dissolved and combined oxygen.

3.10 Final disposal

The action of permanently depositing sludge and biosolids in authorized sites.

3.11 Stabilization

The physical, chemical or biological processes to which sludge is subjected in order to condition it for use or final disposal to avoid or reduce its polluting effects on the environment.

3.12 Alkaline stabilization

The process by which sufficient quicklime (calcium oxide CaO) or hydrated lime (calcium hydroxide Ca(OH)2) or equivalent is added to the mass of sludge and biosolids to raise the pH.

3.13 Helminth

Term for a large group of free-living, parasitic worms (of humans, animals and plants) of various shapes and sizes. They have differentiated organs, and their life cycles include the production of eggs or larvae, infective or not.

3.14 Viable helminth eggs

Helminth eggs susceptible to development and infection.

3.15 The Secretariat

Secretariat of Environment and Natural Resources.

3.16 Maximum permissible limit

Value assigned to a parameter, which must not be exceeded by sludge and biosolids in order to be disposed of or used.

Friday, August 15, 2003 OFFICIAL GAZETTE 21

3.17 Leachate

Liquid from sludge and biosolids, which is formed by reaction or percolation and contains dissolved or suspended contaminants.

3.18 Sludge

Solids with a variable moisture content from the cleaning of urban or municipal sewage systems, water treatment plants and wastewater treatment plants that have not been subjected to stabilization processes.

3.19 Soil improvement

The application of biosolids on land to improve its physical, chemical or microbiological characteristics.

3.20 Sample

A representative part of a finite universe or population, obtained to determine its characteristics.

3.21 Parasite

Animal or plant organism that lives on or within an individual of another species.

3.22 Pathogen

Microorganism capable of causing disease, if present in sufficient quantity and under favorable conditions.

3.23 Salmonella spp.

Bacilli motile by their peritrichous flagella, which characteristically ferment glucose and mannose without producing gas, but do not ferment lactose or sucrose. Most produce hydrogen sulfide (H2S). They are often pathogenic to humans and animals when ingested, causing typhoid fever and enterocolitis (also known as gastroenteritis).

3.24 Urban or municipal sewage system

It is the set of works and actions that allow the provision of a public sewage service, including sanitation, understood as the conduction, treatment, removal and discharge of wastewater.

3.25 Total Solids (TS)

These are the residual materials remaining in sludge and biosolids, which have been dewatered between 103°C to 105°C, to a constant weight and are equivalent on a dry weight basis.

3.26 Volatile Solids (VS)

These are total organic solids present in sludge and biosolids, which volatilize when they are burned at 550°C in the presence of air for a given time.

3.27 Specific Oxygen Uptake Rate (SOUR)

The mass of oxygen consumed per unit time and per unit mass in dry weight of the total solids of the sludge and biosolids.

3.28 Land for agricultural purposes

Land on which agricultural products can be grown for human and animal consumption, including pastures.

4. Specifications

4.1 Individuals or legal entities interested in carrying out the use or final disposal of sludge and biosolids referred to in this Official Mexican Standard must obtain the "certificate of non-hazardousness" in terms of

SEMARNAT-07-007.

4.1.1 In the case of the alkaline stabilization process, sludge samples must be taken before being subjected to this process.

4.2 Sludge and biosolids that comply with specification 4.1 can be managed as non-hazardous waste for use or final disposal as established in this Official Mexican Standard.

4.3 In order for biosolids to be used, they must comply with specifications 4.4, 4.5, 4.6, 4.7 and 4.8; and with Tables 1, 2 and 3 of this Official Mexican Standard.

4.4 Biosolids generators must control the attraction of vectors, demonstrating their effectiveness. For this purpose, any of the options described in Attachment 1, or others that the responsible party demonstrates that they are useful for this purpose, can be applied. The control records must be kept for at least 5 (five) years after

22 OFFICIAL GAZETTE Friday, August 15, 2003 their generation.

4.5 For the purposes of this Official Mexican Standard, biosolids are classified in type: excellent and good according to their content of heavy metals; and in class: A, B and C according to their content of pathogens and parasites.

4.6 The maximum permissible limits for heavy metals are established in Table 1.

TABLE 1

MAXIMUM PERMISSIBLE LIMITS FOR HEAVY METALS IN BIOSOLIDS

CONTAMINANT (determined as total)

EXCELLENT mg/kg dry basis

GOOD mg/kg dry basis

Arsenic 41 75

Cadmium 39 85

Chromium 1 200 3 000

Copper 1 500 4 300

Lead 300 840

Mercury 17 57

Nickel 420 420

Zinc 2 800 7 500

4.7 The maximum allowable limits for pathogens and parasites in sludge and biosolids are set forth in Table 2.

TABLE 2

MAXIMUM PERMISSIBLE LIMITS FOR PATHOGENS AND PARASITES IN SLUDGES AND BIOSOLIDS

AND PARASITES IN SLUDGE AND BIOSOLIDS

CLASS

BACTERIOLOGICAL

INDICATOR OF

CONTAMINATION

PATHOGENS PARASITES

Fecal coliforms NMP/g dry basis

Salmonella spp. MPN/g dry basis

Helminth eggs/g dry basis

A Less than 1 000 Less than 3 Less than 1 (a)

B Less than 1 000 Less than 3 Less than 10

C Less than 2 000 000 Less than 300 Less than 35

(a) Viable helminth eggs MPN most probable number

4.8 The use of biosolids is established according to the type and class, as specified in Table 3 and their moisture content up to 85%.

Friday, August 15, 2003 OFFICIAL GAZETTE 23

TABLE 3

BIOSOLIDS UTILIZATION

TYPE CLASS UTILIZATION

EXCELLENT A • Urban uses with direct public contact during its application.

• Those established for class B and C

EXCELLENT OR

GOOD

B • Urban uses without direct public contact during application

• Those established for class C

EXCELLENT OR

GOOD

C • Forestry uses

• Soil improvement

• Agricultural uses

4.9 The application of biosolids on land for agricultural and soil improvement purposes will be subject to the provisions of the Federal Plant Health Law and in accordance with applicable regulations.

4.10 The final disposal of sludge and biosolids must comply with specification 4.1 and with the maximum permissible limits for contamination indicator content, pathogens and parasites specified in Table 2, for Class C.

4.11 The sites for the final disposal of sludge and biosolids will be those authorized by the competent authority, in accordance with current regulations.

4.12 Sludge and biosolids that comply with the provisions of this Official Mexican Standard may be stored for a period of up to two years. The site where they are stored must be equipped to prevent infiltration into the subsoil and must have a leachate collection system.

4.13 The mixing of two or more batches of sludge or biosolids is allowed, as long as none of them is classified as hazardous waste and the resulting mixture complies with the provisions of this Official Mexican Standard.

4.14 Sampling and analysis of sludge and biosolids

The generator of sludge and biosolids through accredited laboratories must perform the corresponding sampling and analysis to demonstrate compliance with this Official Mexican Standard and must keep the records for at least 5 (five) years after they are performed.

4.15 The frequency of sampling and analysis for sludge and biosolids will be based on the volume of sludge generated as established in Table 4.

TABLE 4

SAMPLING AND ANALYSIS FREQUENCY

FOR SLUDGE AND BIOSOLIDS

Volume generated per year (Tons/Year) on dry basis

Sampling and analysis frequency Parameters to be determined

Up to 1,500 Once a year Heavy metals, bacteriological indicator of contamination, pathogens and parasites

More than 1,500 up to 15,000

Once per semester Heavy metals, bacteriological indicator of contamination, pathogens and parasites

Greater than 15,000 Once per quarter Heavy metals, bacteriological indicator of contamination, pathogens and parasites

24 OFFICIAL GAZETTE Friday, August 15, 2003

4.16 The generator may be exempted from sampling and analysis of one or more of the parameters established in this Official Mexican Standard, as long as the detection of these parameters is in quantities lower than the maximum limits established, or when the origin of the sludge and biosolids does not contain the contaminants regulated in this Official Mexican Standard, in both cases, the generator must declare it to the Secretariat in writing and under oath. The authority reserves the right to verify such information.

4.17 The generator must have a sludge and biosolids control log, according to Attachment VIl.

5. Sampling and test methods For the sampling and determination of the values and concentrations of the parameters established in this

Standard, the test methods established in Attachments II, III, IV, V and VI of this Official Mexican Standard must be applied.

6. Conformity evaluation The conformity assessment of this Official Mexican Standard shall be carried out at the request of a party, in accordance with the provisions of the Federal Law on Metrology and Standardization and its Regulations.

The verification procedure will be carried out by PROFEPA or by the verification units and laboratories accredited and approved to carry out the verification. In case there are accredited verification units for this Standard, the verification will be carried out exclusively through them.

7. Degree of concordance with international standards and guidelines This Official Mexican Standard does not agree with any international standard or guideline, nor are there any

Mexican standards that have served as a basis for its elaboration.

8. Bibliography

8.1 A Guide to the Biosolids Risk Assessments for the EPA Part 503 Rule. EPA 832-B-93-005.

Environmental Protection Agency USA. September 1995 (Guide to the Biosolids Risk Assessments for the EPA. Part 503, EPA Rule 832-B-93-005.- Environmental Protection Agency USA. September 1995).

8.2 A Plain English Guide to the EPA Part 503 Biosolids Rule. EPA/832/R-93/003. Environmental Protection Agency USA. September 1994 (A Plain English Guide to the EPA Part 503 Biosolids Rule. Part 503 Biosolids Rule EPA/832/R-93/003.-Environmental Protection Agency USA. September 1994).

8.3 APHA, AWWA, WPCF. 1992 Standard Methods for the Examination of Water and Wastewater. 18th Ed.

18th Ed. American Public Health Association. Washington, D.C. (Established Methods for the Analysis of Water and Wastewater. 18th Ed. 18th Ed. American Public Health Association. Washington, D.C.).

8.4 Biosolids Treatment and Management. Processes for Beneficial Use. Marcel Dekker, Inc. 1996 (Biosolids Treatment and Management - Processes for Beneficial Use - Marcel Dekker, Inc. 1996).

8.5 Campos, R., Maya, C. and Jiménez, B. "Alkaline Thermal Stabilization of Chemical Sludge with a High Content of Pathogenic Microorganisms". XIX Encuentro Nacional AMIDIQ, Academia Mexicana de Investigación y Docencia en Ingeniería Química, A.C. Memorias pp. 365-366, Ixtapa- Zihuatanejo, Gro., May 13-15, 1998.

8.6 Environmental Regulations and Technology. Use And Disposal Of Municipal Wastewater Sludge. EPA 625/10-84-003. Environmental Protection Agency USA. September 1984 (Environmental Regulations and Technology - Use And Disposal Of Municipal Wastewater Sludge. epa 625/10-84-003). EPA 625/10-84-003.

Environmental Protection Agency of the United States of America. September 1984).

8.7 Environmental Regulations and Technology. Control of Pathogens in Municipal Wastewater Sludge.

EPA/625/10-89/006. Environmental Protection Agency USA. Environmental Regulations and Technology.

Control of Pathogens in Municipal Wastewater Sludge. epa/625/10-89/006. EPA/625/10-89/006. Environmental Protection Agency of the United States of America. September 1989).

8.8 Fundamento técnico para la elaboración de la Norma Oficial Mexicana en materia de estabilización, manejo y aprovechamiento de lodos provenientes de plantas de tratamiento de aguas municipales e industriales (Technical basis for the elaboration of the Official Mexican Standard on stabilization, handling and use of sludge from municipal and industrial water treatment plants). Institute of Engineering of the UNAM. 1997.

8.9 Geochemistry, Groundwater and Pollution. C.A.J. Appelo and D. Postma.- A.A. Balkema/Rotterdam/ Brookfield/1996. (Geochemistry, Groundwater and Pollution. C.A.J. Appelo and D. Postma.- A.A. Balkema/ Rotterdam/ Brookfield/1996).

8.10 Goepfert, J., Olson, N. and Marth, E., 1968. Behavior of Salmonella typhimurium During Manufacture and Curing of Cheddar Cheese. Applied Microbiology. 16: 862-866. (Behavior of Salmonella typhimurium During Processing and Curing of Cheddar Cheese. Applied Microbiology 16: 862-866.

Friday, August 15, 2003 OFFICIAL GAZETTE 25

8.11 Ground Water, Quality Protection. Larry W. Canter, Robert C. Knox, and Deborah M. Fairchild. Lewis Publishers, Inc. 198 (Ground Water, Protective Characteristics.- Larry W. Canter, Robert C. Knox, and Deborah M. Fairchild. Lewis Publishers, Inc. 1987).

8.12 Guide for the management, treatment and utilization of sewage sludge from municipal treatment plants.

National Water Commission. SGIHUI. 1994.

8.13 Guide for the management, stabilization and disposal of chemical sludge. Potabilization. National Water Commission. SGIHUI. 1994.

8.14 Jawetz, E., Melnick, J. and Adelberg, E., 1995. Medical Microbiology. Ed. Manual Moderno. Mexico,

pp. 803.

8.15 Jiménez B., Barrios, J.A. and Maya, C. 1999. Class B Biosolids Production from Wastewater Sludge with High Pathogenic Content Generated in an Advanced Primary Treatment. Disposal and Utilisation of Sewage Sludge: Treatment Methods and Application Modalities. Water Resources, Hydraulics and Maritime Engineering NTUA. Athens, Greece 13-15 October 1999 (Production of Class "B" biosolids from sewage sludge with high pathogenic content generated in an advanced primary treatment. Disposal and utilization of sewage sludge.

Treatment methods and application techniques. Water resources, marine engineering and hydraulics NTUA.

Athens, Greece, October 13-15, 1999).

8.16 Jiménez C.B., Muñoz C.A. M. and Barrios Pérez, J. A., 1997. Technical Basis for the Elaboration of the Official Mexican Standard on the Stabilization, Management and Use of Sludge from Municipal and Industrial Water Treatment Plants. Prepared for the Comisión Nacional del Agua (CNA) by the Instituto de Ingeniería, UNAM. Project 8313, pp. 107 (December, 1997).

8.17 Jiménez, B., Chávez, A., Barrios, J.A., Maya, C. and Salgado, G., 1998. Manual "Curso: Determinación y Cuantificación de Huevos de Helminto Norma Mexicana NMX-AA-113-SCFI/992". Grupo Tratamiento y Reuso, Instituto de Ingeniería UNAM. pp. 160,

8.18 Jiménez, B., Maya, C. and Pulido, M., 1996. Evaluation of the Different Techniques for the Detection of Helminth Eggs, and Selection of one to Conform the Corresponding NMX. Institute of Engineering, UNAM.

Mexico, pp. 52.

8.19 Ley General del Equilibrio Ecológico y la Protección al Ambiente. 1996.

8.20 Manual of good practice for utilization of sewage sludge in agriculture. 2nd. Revision October 1991.

Anglian Water (Manual of good practice for utilization of sewage sludge in agriculture. 2nd Revision October 1991. Water).

8.21 Miller, V. And Banwart, G., 1965. Effect of Various Concentration of Brilliant Green and Bile Salts on Salmonellae and Other Microorganisms. Applied Microbiology. 13: 77-80. (Effect of Various Concentration of Brilliant Green and Bile Salts on Salmonellae and Other Microorganisms. Applied Microbiology. 13: 77-80).

8.22 Norma Oficial Mexicana NOM-001-ECOL/1996, Que establece los límites máximos permisibles de contaminantes en las descargas de aguas residuales en aguas y bienes nacionales (Diario Oficial de la Federación 6 de enero de 1997).

8.23 Norma Oficial Mexicana NOM-008-SCFI/1993, Sistema General de Unidades de Medida, (Official Mexican Standard NOM-008-SCFI/1993, General System of Measurement Units, Official Gazette of the Federation, October 14, 1993).

8.24 Norma Oficial Mexicana NMX-AA-015-1985, Protección al Ambiente-Contaminación del Suelo- Residuos Sólidos Municipales-Muestreo-Método de Cuarteo-Environmental Protection-Soil Pollution-Municipal Solid Residues-Sampling-Quarter Method (Diario Oficial de la Federación 18 de marzo de 1985).

8.25 Norma Mexicana NMX-AA-113-SCFI/1999, Análisis de Agua - Determinación de Huevos de Helminto.

Test Method (Diario Oficial de la Federación August 5, 1999).

8.26 Regulation of clarification sludge. Germany. April 15, 1992.

8.27 United States Environmental Protection Agency (U.S.E.P.A.) Regulation for the Use or Application of

Dredging Sludge, Part 503 of 40 CFR, published in the Federal Registry on February 19, 1993.

8.28 Reglamento de la Ley General del Equilibrio Ecológico y la Protección al Ambiente en materia de Residuos Peligrosos (Reglamento de la Ley General del Equilibrio Ecológico y la Protección al Ambiente en materia de Residuos Peligrosos) (Diario Oficial de la Federación, November 25, 1988).

8.29 Santos Mendoza, Salvador. "Stabilization with Lime of Sludge from the Advanced Primary Treatment Pilot Plant". Environmental Engineering, DEPFI- UNAM. June 15, 1998. Master's Thesis.

26 OFFICIAL GAZETTE Friday, August 15, 2003

8.30 Santos M., S., Campos M., R. and Jiménez C., B. "A Management Option for the Sludge Generated when Treating the Wastewater of the Mexico City Grand Canal". 1st Latin American Symposium on Water and Industrial Waste Treatment and Reuse. Proceedings Volume I, pp. 28-1-28-10, May 25-29, 1998, Mexico City, Mexico.

8.31 Satchwell, G.M., 1986. An Adaptation of Concentration Techniques for the Enumeration of Parasitic Helminth Eggs from Sewage Sludge. Water Res. 20: 813-816.

8.32 Schaffner, C., Mosbach K., Bibit V. and Watson C., 1967. Coconut and Salmonella Infection. Applied Microbiology. 15: 471-475. (Coconut and Salmonella Infection. Applied Microbiology. 15: 471-475.)

8.33 Shiflett M., Lee J. and Sinnhuber, R., 1967. Effect of Food Additives and Irradiation on Survival of Salmonella in Oysters. Applied Microbiology. 15: 476-479. (Effect of food additives and irradiation on survival of Salmonella in oysters. Applied Microbiology. 15: 476-479).

8.34 Silliker, J. Deibel, R. and Chiu, J., 1964. Occurrence of Gram-Positive Organisms Possessing Characteristics Similar to Those of Salmonella and the Practical Problem of Rapid and Definitive Salmonella Identification. Applied Microbiology. 12: 395-399. (Occurrence of Gram-Positive Organisms Possessing Characteristics Similar to Those of Salmonella and the Practical Problem of Rapid and Definitive Salmonella Identification. Applied Microbiology. 12: 395-399).

8.35 Silliker, J" Deibel, R. and Fagan, P., 1964. Isolation of Salmonella from Food Samples: VI Comparison of Methods for the Isolation of Salmonella from Egg Products. Applied Microbiology. 12: 224-228. (Isolation of Salmonella from Food Samples: VI. Comparison of methods for the isolation of Salmonella from egg products.

Applied Microbiology. 12: 224-228.

8.36 Sludge Management & Disposal. For The Practicing Engineer. P.A. Vesilind, G.C., Hartman and E.T., Skene. Lewis Publishers, Inc. 1986 (Sludge Management and Disposal. For Professional Engineers. P.A.

Vesilind, G.C. Hartman and E.T., Skene. Lewis Publishers, Inc. 1986).

8.37 Standard Methods for the Examination of Water and Wastewater, 19th. Edition. American Public Health Association. American Water Works Association. Water Environment Federation. Standard Methods for the Examination of Water and Wastewater, 19th Edition. American Public Health Association. American Treated Water Association. Water Environment Federation 1995).

8.38 Sludge Stabilization. Manual of Practice FD-9. Facilities Development. Water Environment Federation 1993 (Sludge Stabilization. Manual of Practice FD-9. Facilities Development. Water Environment Federation 1993).

8.39 Standards for the Use or Disposal of Sewage Sludge; Final Rules. 40 CFR Parts 257, 403 and 503.

Environmental Protection Agency. USA. Federal Register Friday February 19, 1993. Standards for the Use or Disposal of Sewage Sludge, Regulations 40 CFR Parts 257, 403 and 503. Environmental Protection Agency.

USA. Federal Register February 19, 1993.)

8.40 Sludge Conditioning. Manual of Practice FD-14. Water Pollution Control Federation. 1988. Alexandria, VA. (Manual of Practice FD-14 Sludge Conditioning. Water Pollution Control Federation. 1988) and Alexandria, VA. 1988.) and Alexandria, VA.

8.41 Stuart, P. and Pivnick, H., 1965. Isolation of Salmonellae by Selective Motility Systems Applied Microbiology 13: 365-372. Applied Microbiology 13: 365-372).

8.42 Taylor, W., Betty, C. and Muriel, E., 1964. Comparison of Two Methods for Isolation of Salmonella from Imported Foods. Applied Microbiology 12: 53-56. (Comparison of two methods for isolation of Salmonella from imported foods. Applied Microbiology. 12: 53-56).

8.43 US EPA 1994, Land Application of Sewage Sludge: A Guide for Land Appliers on the Requirements of the Federal Standards for the Use of Disposal of Sewage Sludge, 40 CFR Part 503. USA. pp. 62. (Land Application of Sewage Sludge: A Guide for Land Appliers on the Requirements of the Federal Standards for the Use and Disposal of Sewage Sludge, 40 CFR Part 503. Water Environment Federation. . pp. 62. USA. pp. 62).

8.44 US EPA/625/R92/013 1992, Environmental Regulation and Technology, Control of Pathogens and Vector Attraction in Sewage Sludge pp. 152. Control of Pathogens and Vector Attraction in Sewage Sludge pp.

152.)

9. Enforcement of this Standard

9.1 Enforcement of this Official Mexican Standard is the responsibility of the Ministry of the Environment and Natural Resources, through the Federal Environmental Protection Agency, as well as the state, municipal and Federal District governments, within the scope of their respective competencies. Violations will be sanctioned

Friday, August 15, 2003 OFFICIAL GAZETTE 27 according to the terms of the General Law of Ecological Balance and Environmental Protection, its regulations and other applicable legal ordinances. The Ministry of the Environment and Natural Resources, through the Federal Attorney's Office for Environmental Protection, as well as the state, municipal and Federal District governments, within the scope of their respective competencies, will periodically or randomly carry out sampling and analysis of sludge and biosolids, in order to verify compliance with the maximum permissible limits of contaminants established in this Official Mexican Standard.

TRANSITORY ARTICLES

FIRST.- This Official Mexican Standard shall enter into force 60 days after its publication in the Official Gazette of the Federation.

SECOND.- Based on the provisions of Article 47 section IV of the Federal Law on Metrology and Standardization, provide for the publication of this project in the Official Gazette of the Federation.

Mexico City, Federal District, on the fifteenth day of April, two thousand three.- The Undersecretary of Environmental Development and Standards of the Secretariat of the Environment and Natural Resources, and President of the National Consultative Committee of Standardization of the Environment and Natural Resources, Cassio Luiselli Fernandez.- Signature.

ATTACHMENT I

OPTIONS FOR VECTOR ATTRACTION REDUCTION

Responsible parties may apply any of the following options for vector attraction control or any other that is proven to be effective.

Option 1: Reduction in Volatile Solids Content

Vector attraction is reduced if the mass of volatile solids in the biosolids is reduced by at least 38% during treatment. This percentage is equivalent to that achieved by aerobic or anaerobic digestion plus any additional reduction that occurs after the biosolids leave the stabilization facilities, such as processing in drying beds or lagoons or by composting.

Option 2: Additional digestion of anaerobically digested biosolids

Frequently, biosolids have been recycled through biological wastewater treatment or have been in transit for long periods in sewage systems. During this time, they undergo substantial biological degradation. If the biosolids are subsequently treated by anaerobic digestion, their vector attraction will be adequately reduced. Because they enter the digester partially stabilized, the reduction in volatile solids after treatment is often less than 38%. Under these circumstances, the 38% reduction required in Option 1 may not be feasible. Option 2 allows the operator to demonstrate vector attraction reduction by testing a portion of the previously digested biosolids in a laboratory-scale unit. Reduction is demonstrated if, after anaerobic digestion of the biosolids for an additional 40 days at a temperature between 30°C and 37°C, the reduction of volatile solids in the biosolids is less than 17%.

Option 3: Additional digestion of aerobically digested biosolids

This option is appropriate for aerobically digested biosolids that cannot comply with option 1, including those produced by extended aeration plants where the minimum residence time for biosolids in the water train generally exceeds 20 days. In these cases, the biosolids will already be substantially degraded prior to aerobic digestion.

Under this option, aerobically digested biosolids with 2% solids or less are considered to have achieved vector attraction reduction if after 30 days of aerobic digestion in a laboratory test at 20°C, the reduction in volatile solids is less than 15%. This test is only applicable to aerobically digested liquid biosolids.

Option 4: Aerobic processes above 40°C

This option applies primarily to composted biosolids that also contain partially decomposed organic bulking agents. The biosolids must be treated aerobically for 14 days or more, during which time the temperature must always exceed 40°C and average greater than 45°C. This option could be applied to other aerobic processes, such as aerobic digestion, however, options 3 and 4 seem easier to accomplish for the other aerobic processes.

Option 5: Addition of alkaline matter Biosolids are considered to adequately reduce their vector attraction if sufficient alkaline matter is added to accomplish the following:

♦ Raise the pH to at least 12, measured at 25°C, and without the addition of further alkaline matter, 28 OFFICIAL GAZETTE Friday, August 15, 2003 maintain for 2 hours, and

♦ Maintain a pH of at least 11.5 without the addition of further alkaline matter for another 22 hours.

These conditions are intended to ensure that the biosolids can be stored for at least several days at the treatment facility, transported and subsequently applied without the pH dropping to levels where spoilage occurs and vectors are attracted.

Option 6: Moisture reduction of biosolids that do not contain unstabilized solids.

Vector attraction is considered to be reduced if the biosolids do not contain unstabilized solids generated during primary treatment and their solids content is at least 75% prior to mixing with other materials. Therefore, reduction should be achieved by removing water and not by the addition of inert materials.

It is important that biosolids do not contain unstabilized solids because the partially degraded food waste that is likely to exist in such biosolids would attract birds, some mammals, and possibly insects even if the solids content is greater than 75%.

Option 7: Moisture reduction in biosolids containing unstabilized solids

The ability of any biosolids to attract vectors is considered to be adequately reduced if their solids content is increased to 90% or more regardless of whether the biosolids are from primary treatment. The increase should be achieved by removing water and not by dilution with inert solids. Drying to this point severely limits biological activity and destroys or breaks down volatile compounds that attract vectors.

The manner in which dried biosolids are handled, including their storage prior to application, can be conducive to vector attraction. If exposed to high humidity, the outer surface will have a high moisture content and possibly attract vectors. This should be adequately prevented.

Option 8: Specific Oxygen Uptake Rate (SOUR) for aerobically digested biosolids

Frequently, aerobically digested biosolids are circulated through aerobic biological wastewater treatment processes for up to 30 days. In these cases, the biosolids entering the aerobic digester are already partially digested, making it difficult to meet Option 1.

Specific Oxygen Uptake Rate (SOUR) is the mass of oxygen consumed per unit time and per unit dry weight mass of the total solids in the biosolids. Reduction in vector attraction can be demonstrated if the SOUR of the biosolids being applied, determined at 20°C, is equal to or less than 1.5 mg of 02/h/g of total solids (dry weight).

This test is based on the fact that, if the biosolids consume very little oxygen, their value as a food source for microorganisms is too low to attract them. Other temperatures can be used for the test if the results are corrected on the basis of 20°C. This test is only applicable to aerobic biosolids.

Option 9: Incorporation of Biosolids into Soil

Biosolids must be incorporated into the soil within 6 hours after land application. Incorporation is accomplished by plowing or some other method that mixes the biosolids with the soil. If the biosolids are Class A with respect to pathogens, the time between application and processing should not exceed 8 hours.

ATTACHMENT II

SLUDGE AND BIOSOLIDS SAMPLING METHODS

It consists of obtaining a portion of the volume generated, which must conserve the integrity of all its constituents from the moment the sample is taken (representative part of a universe or finite population obtained to know its characteristics) until the end of its analysis or determination in the laboratory. The time in which they remain stable will depend on their characteristics and the preservation method used. Sampling is an integral and fundamental part of assessing the quality of sludge and biosolids for final disposal.

The size and number of samples depend on the generating sources, as well as the processes used for their stabilization. It is important to consider the selection of the sampling site, the homogeneity and representativeness of the sample, the degree of degradation, the volume, type of analysis and accessibility to the selected sampling site.

1. Method

Obtain representative samples of sludge and biosolids to determine their content of fecal coliforms, Salmonella spp., helminth eggs, specific oxygen uptake rate, total solids and volatile solids content, arsenic, cadmium, chromium, copper, lead, mercury, nickel and zinc.

Friday, August 15, 2003 OFFICIAL GAZETTE 29

1.1 Equipment and materials

Only equipment and materials that are of relevance to the present method are listed.

1.1.1 Equipment.

1.1.1.1 Scale with a minimum capacity of 100 kg and 10 g accuracy.

1.1.1.2 Scale with a minimum capacity of 10 kg and an accuracy of 1 g.

1.1.1.3 M 2.00 sieve according to Mexican Standard NMX-B-231-1990.

1.1.2 Materials.

1.1.2.1 Pitchforks.

1.1.2.2 Polyethylene bags of 0.70 m x 0.50 m and minimum caliber No. 200.

1.1.2.3 Polyethylene bags of 1.10 m x 0.90 m and minimum caliber of No. 200.

1.1.2.4 Rubber boots.

1.1.2.5 Brush of adequate size for cleaning.

1.1.2.6 Safety helmets.

1.1.2.7 Brooms.

1.1.2.8 Leather gloves.

1.1.2.9 1.5 mm wide rubber bands.

1.1.2.10 Permanent ink markers, preferably black.

1.1.2.11 Protective masks.

1.1.2.12 Coveralls.

1.1.2.13 Stationery and miscellaneous (sampling forms, pencils, erasers and others).

1.1.2.14 Stationery and miscellaneous (field report, markers, rubber bands, etc.).

1.1.2.15 Curved shovels.

1.1.2.16 Pickers.

1.1.2.17 Inventory tables, letter or legal size.

1.1.2.18 Cylindrical metal drums, with a capacity of 20 L.

1.1.2.19 Sterile polyethylene bags without thiosulfate tablet or polyethylene or inert propylene containers, with wide mouth, lid and airtight seal, 500 ml capacity and autoclavable, for fecal coliforms.

1.1.2.20 Polyethylene or inert propylene or glass containers, wide mouth, with lid and hermetic seal, of 50 ml, for metals.

1.1.2.21 Polyethylene or inert propylene or glass containers, wide mouth, with lid and hermetic seal, 500 ml capacity, for helminth eggs, solids and SOUR.

2. Types of sludge

2.1 Liquid or semi-solid samples.

Collect the sample directly from the spillway in a 20 L plastic container, up to twice the volume to be used for each of the analyses to be performed, as a minimum.

2.1.1 Pipes

Collect the sample directly from the pipe through the purge tap with a minimum internal diameter of 3.8 cm.

2.1.2 Channels

Collect the sample at the spillway or at another point where the sludge is well mixed.

2.1.3 Digestors

Collect the sample from a mixed tank that is fed through lines from different levels in the digester. Before sampling be sure to remove the sludge previously accumulated in the lines.

30 OFFICIAL GAZETTE Friday, August 15, 2003

2.1.4 Tanks

Thoroughly mix the tank and collect several samples at different depths and points. Pool all samples into one sample before analysis.

2.1.5 Site-specific sludge from treatment plants

The following sampling points are recommended for sludge sampling at wastewater treatment plants.

2.1.6 Primary sludge

Drive the sludge from the stabilization tank to the sump prior to pumping, mix thoroughly and collect a representative sample at this point. Alternatively, collect samples from the sludge pump and pipelines in the vicinity of the sludge pump and pipelines.

2.1.7 Activated sludge

Collect samples at:

a) pump sump

b) from the adjacent pump or pipeline

c) from the point of discharge of the return sludge to the primary influent

The sampling point should be located in a region of good agitation for solids suspension.

2.1.8 Digested sludge

Collect samples at the discharge pipe from the digester to the drying bed(s).

2.1.9 Drying bed sludge

Collect samples of the same size at different points in the bed without including sand. Mix thoroughly.

2.1.10 Filtered sludge

Collect same size portions (use cookie cutters) at filter discharge.

2.1.11 Silt

In the case of silt, it applies when a representative sample of the area where it is deposited has been extracted.

2.2 Solid samples

To make up the samples, the quarter method is used. For that:

4 to 8 polyethylene bags of 0.70 m x 0.50 m or 1.10 m x 0.90 m are taken, the same number of different sites are randomly selected. Subsequently, each of the bags is filled with the material from each site and moved to a flat horizontal area of approximately 4 m x 4 m, preferably of polished concrete or similar and under a roof, and the contents are deposited in a mound.

Shovel the material with a shovel or a shovel-rod to obtain a homogeneous mixture. Then divide into four approximately equal parts A, B, C and D and remove the opposing parts A and C or B and D. Repeat this operation until approximately 10 kg of sludge or biosolid is left. The resulting pile is used for laboratory determination of fecal coliform, Salmonella ssp., helminth eggs, total solids and volatile solids content, arsenic, cadmium, chromium, copper, lead, mercury, nickel and zinc. The remaining material is used to determine the volumetric weight of the sludge in situ, according to point 8.

Transfer the sample to the laboratory in polyethylene bags properly sealed and identified (see marking). Avoid exposing them to the sun during transport and take care in handling the bag containing the sample so that it does not suffer any breakage. The maximum transport time of the sample to the laboratory should not exceed 8 hours.

3. Sample preparation

The sampling sequence for each parameter should be carried out as described in the corresponding points in order to minimize biases in the results.

4. Containers for each parameter

Before being processed, the total solids content of the sample shall be determined in percent by weight; in the case of TEAO, the content of these shall be less than or equal to 2%.

4.1 Fecal coliforms and Salmonella spp.

Friday, August 15, 2003 OFFICIAL GAZETTE 31

The polyethylene or inert polypropylene containers of 500 ml capacity, before sampling, should be preferably sterilized in an autoclave. Subsequently, the sample corresponding to 4 g of total solids is deposited. Label it and keep it refrigerated until analysis.

4.2 Helminth Eggs, Total Solids and Volatile Solids and TEAO

Polyethylene or inert polypropylene containers of 500 ml capacity, prior to sampling should be rinsed first with potable tap water and then with distilled water.

In the case of helminth eggs, the fresh weight corresponding to 2 g of total solids is taken. For total and volatile solids and TEAO, the containers are filled to 75% of their total capacity, closed, labeled and kept refrigerated until analysis, except for TEAO, which is kept at room temperature.

4.3 Inorganic compounds: arsenic, cadmium, copper, chromium, mercury, nickel, lead and zinc.

The polyethylene or inert polypropylene glass container of 50 ml capacity, before sampling, should be rinsed first with potable water and then with distilled water.

Subsequently, the sample is deposited up to the total capacity, closed, labeled and kept refrigerated until analysis.

4.4 Preservation and storage of the sample

The preservation and maximum time for the analysis of each parameter is as follows:

PARAMETERS PRESERVATION* MAXIMUM ANALYSIS

TIME

Fecal coliforms and Salmonella spp. 4°C 48 hours

Helminth eggs 4°C 30 days

Arsenic, cadmium, copper, chromium, nickel, lead, and zinc 4°C 180 days

Mercury 4°C 13 days(a) (plastic)

38 days(b) (glass)

Total solids 4°C 24 hours

Volatile solids 4°C 24 hours

Specific oxygen uptake rate ** Not required Not required Immediate

*The sample should be kept refrigerated from the time it is taken until analysis is started.

**If the sample is taken in the laboratory, it must be kept at constant or ambient temperature during transport and analyzed immediately.

5. Quality Control The sampling program should operate a quality control system.

5.1 The person responsible for the sampling must keep records of the names and titles of the technicians who performed the sampling and the quality control officer who verified the samples, and logs or forms containing at least the following information:

a) Identification of the sample.

b) Quantity of sample used.

c) Type of sample.

d) Type of analysis to be performed.

e) In addition, the original information reported by the technical personnel involved in the sampling, transfer and reception of the samples, as well as the complementary information, must be kept.

6. Labeling The sample is identified with a label, which must contain the following information:

• Locality, Municipality and State.

• Date and time of quartering.

32 OFFICIAL GAZETTE Friday, August 15, 2003

• Climatic conditions.

• Quantity of sludge taken for quartering, in kg.

• Quantity of sludge obtained for selection into by-products, in kg.

• Data of the person in charge of the quartering.

• Remarks.

7. Calculations

7.1 To determine the volumetric weight of the sludge, clean containers without dents are used. The scale used must be level.

7.2 Then the empty container is weighed, taking this weight as the tare weight of the container. It is filled to the top with the homogenized sludge obtained from the parts removed from the first quartering (described above).

7.3 The container is struck against the ground three times, dropping it from a height of 10 cm. Fill up to the top taking care not to press it when placing it in the container; this in order not to alter the volumetric weight to be determined.

7.4 It is important to empty all the material into the container, without discarding the fines. To obtain the net weight of the sludge, the container is weighed with these and the value of the tare is subtracted. When there is not enough material to fill the container, the height reached is marked on the container and the volume is determined.

The volumetric weight of the sludge is calculated by the following formula:

where:

Pv: Volumetric weight of the sludge, in kg/m3

P: Sludge weight (gross weight minus tare weight), kg

V: Volume of the vessel, in m3

8. Interferences Collect samples at a time when the parameter to be analyzed is unstable, e.g. Specific Oxygen Uptake Rate

(SOUR), or when the analysis needs to be performed as soon as possible (e.g. microbiological analysis).

ATTACHMENT III

METHOD FOR THE QUANTIFICATION OF FECAL COLIFORMS IN SLUDGE AND BIOSOLIDS

This method establishes the technique to carry out the quantification of the fecal coliform group in sludge and biosolids, in order to evaluate the quality and efficiency of the different treatments, and is applicable for the evaluation of the quality of sludge and biosolids.

1. Principles of the method This method of analysis is based on the fact that:

1.1 Bacteria present in a sample can be separated by agitation, resulting in a suspension of bacterial cells, uniformly distributed.

1.2 Through successive dilutions of the sample, inocula of at least one cell are obtained to obtain growth in the culture medium (positive tubes), and others that when seeded give results in at least one tube of the series.

1.3 The combination of positive and negative results allows an estimation of the bacterial density by means of probability calculations.

1.4 The selected technique allows the study of a…