4.1 Substitute wastewater may be used for laboratory testing where a reproducible mixture simulating municipal wastewater is required. To provide a more rugged evaluation of a test method's ability to measure analytes and the precision of the test method under more demanding conditions, it is necessary to utilize a matrix more complex than reagent water. Substitute wastewater is intended to be used as a material to be spiked with analytes or interferents of interest to evaluate the performance of test methods.

4.2 Utilization of substitute wastewater as a matrix in interlaboratory validation studies will allow inclusion of performance statistics for this matrix in the Precision and Bias section of test methods. Users of test methods will be able to evaluate their application of test methods in this matrix against published results.

1.1 This practice covers the preparation of an aqueous mixture containing constituents in concentrations such that it will have physical and chemical matrix characteristics similar to municipal wastewater.

1.2 Wastewaters are extremely variable, depending on the quantity and nature of the materials being discharged into the collection system. The mixture prepared with this practice is not representative of any particular wastewater. Rather, it allows the user to prepare a mixture that exhibits a similar matrix impact on test method performance as is typical of municipal wastewater and can be prepared from common materials inexpensively and reproducibly. It allows the evaluation of test methods, over time, against the same reference point.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.