ARTICLE 278-B:

For the purposes of the accreditation referred to in article 278 of this Law (LFD: Art. 278), the concentrations of pollutants discharged to the receiving body shall be determined quarterly, in accordance with the following:

I. (Repealed).

II. The person responsible for the discharge will carry out the sampling and analysis of the quality of the discharged water, in samples of each of its discharges to verify the concentrations of the pollutants referred to in this Law.

The reports submitted by the person responsible for the discharge will be based on analytical determinations made by a laboratory accredited before the entity authorized by the Secretary of Economy (Secretaría de Economía) and approved by the National Water Commission (Comisión Nacional del Agua).

II. In the Sampling Procedure of the Discharges, it will be understood as:

a. Composite Sample: The one that results from mixing the number of simple samples, as indicated in the sampling frequency table. To form the composite sample, the volume of each of the simple samples must be proportional to the discharge rate at the time of collection.

Table A.- Sampling Rate

b. Simple Sample: The one that is taken at the point of discharge, on a continuous basis, on a normal day of operation for the time necessary to complete, at least, a sufficient volume so that the necessary analyzes are carried out to know its composition, increasing the flow discharged at the site and at the time of sampling.

The volume of each simple sample necessary to form the composite sample is determined by the following equation:

VMSi = VMC x (Qi/Qt), where:

VMSi = volume of each of the simple samples "i", liters.

VMC = volume of each composite sample needed to perform all required laboratory analyzes, liters.

Qi = flow measured in the discharge at the time of taking the simple sample, liters per second.

Qt = * Qi up to Qn, liters per second.

c. Parameter: Variable that is used as a reference to determine the physical, chemical and biological quality of water.

d. Daily Average: The value that results from the analysis of a composite sample.

e. Monthly Average: The value that results from calculating the weighted average based on the flow, of the values that result from the analysis of at least two composite samples daily average.

IV. The sampling, analysis and reporting of the quality of the discharge will be carried out as indicated below:

a. Sampling Method: The method to be carried out when taking samples, as well as the terms and manner of doing them, are those indicated in Mexican Standard NMX-AA-003-1980 Wastewater-Sampling, published in the Official Journal of the Federation (Diario Oficial de la Federación) on March 25, 1980.

b. Frequencies of Sampling and Analysis, and of the Report of Data: The frequency of sampling and analysis and of the report will be according to the size of the population in the case of municipal effluents, and in the case of non-municipal discharges, according to the load of pollutants, as indicated in the tables of municipal effluents and non-municipal effluents, respectively.

Table B. Municipal Effluents

Table C. Non-Municipal Effluents

The parameters to be considered in the sampling and analysis, as well as in the data report are those indicated in this Chapter.

c. Calculation of the Values: In the sampling and analysis and the report of the data of the parameter or required parameters, the value of the monthly average should be considered according to the definition given in this procedure, and should consider business days of normal activity or production.

The sampling and analysis of the parameter or required parameters at the frequency indicated in the tables of municipal effluents and non-municipal effluents, should consider:

1. For the monthly frequency, the monthly average of the

parameter or parameters in the month.

2. For the quarterly frequency, the monthly average of the parameter or parameters in a month of the quarter.

3. (Repealed).

The report of the results of the sampling and analysis of the parameter or required parameters must be made on a quarterly frequency, in accordance with the provisions of article 283 of this Law. (LFD: Art. 283)

The quarter report, for the monthly frequency of sampling and analysis, will be the arithmetic average of the values resulting from the analysis of each month.

Compliance with the foregoing is without prejudice to the observance of the applicable legal and regulatory provisions regarding the discharge of wastewater to national water bodies and inherent public goods.

d. Test Method: For the sampling and determination of the values and concentrations of the parameters established in this procedure, the test method indicated in this section and in the Official Mexican Standard and corresponding Mexican rules must be applied.

V. For each discharge, the taxpayer will determine, according to the average of samples taken, the average concentration of pollutants in milligrams per liter, according to the discharge sampling procedure established in this article.

VI. In the event that the supply water registers some average monthly concentration, it may be subtracted from the concentration of the discharge, as long as it is accredited before the National Water Commission (Comisión Nacional del Agua), through an analysis of water quality carried out by an accredited laboratory before the entity authorized by the Secretary of Economy (Secretaría de Economía) and approved by the National Water Commission (Comisión Nacional del Agua).

The report referred to in the preceding paragraph may be presented within the first quarter of the fiscal year in question and will be valid during that fiscal year. If requested after the deadline indicated above, the report will be valid from the moment it is submitted.

The National Water Commission (Comisión Nacional del Agua) will be empowered to review the accuracy of the data in the report submitted.

VII. (Repealed).

VII. The laboratories accredited before the entity authorized by the Secretary of Economy (Secretaría de Economía) and approved by the National Water Commission (Comisión Nacional del Agua), must report to said Commission on a quarterly basis on the results of the analyzes carried out in that period to the taxpayers referred to in this Chapter.

In the event that the National Water Commission (Comisión Nacional del Agua) determines that the laboratories did not comply with the obligations established in this article, it will notify the laboratory of the breach and will warn it that in case of recidivism, the approval granted to it will be without effect, in accordance with the provisions in the Federal Administrative Procedure Law (Ley Federal de Procedimiento Administrativo).

The laboratories referred to in this article shall be responsible for the veracity and accuracy of the data and information provided in the reports referred to in this article and shall will respond in solidarity for the payment of the right referred to in this Chapter and of the right for use, exploitation or utilization of national waters by taxpayers for which the accreditation, exemption or discount has been improperly applied due to the report issued by the laboratory.

To determine the responsibility for solidarity to the laboratories referred to in this article, the tax authority shall carry out the procedure referred to in article 42, section II, of the Federal Fiscal Code (Código Fiscal de la Federación). (CFF: Art. 42)