Design Specifications of Sampling Scheme for GB 12997-91 Water Quality
Background
The Water Quality Standard (GB 12997-1991) was formulated by the Ministry of Environmental Protection of the Peoples Republic of China. This standard is applicable to water bodies such as rivers, lakes, reservoirs, and various parts of drinking water sources. The standard requires that water samples be collected properly to reflect the actual water quality and be used as the basis for water pollution control and supervision.
Objective
The objective of this document is to provide technical guidelines on how to collect water samples for water quality analysis in accordance with GB 12997-1991.
Basis
The basis for this document are the provisions of GB 12997-1991 and relevant documents on sampling techniques.
Scope
This document applies to the design of sampling schemes for water quality analysis in accordance with GB 12997-1991. The document does not describe specific methods of sample collection, preservation and other relevant technical details.
Design Requirements
The sampling plan for water quality analysis according to GB 12997-1991 should meet certain requirements. First, the sample collection sites should be representative of the actual water body and its water quality. Consideration should be given to water quality characteristics such as water depth, flow direction, turbulent flow, water temperature, etc.to determine appropriate sampling points.
Second, the number of sample collection points should be determined according to the scope of the water quality analysis and the statistical requirements. The sampling plan should include the total number of sampling points, their locations and relevant information.
Third, the quantity of each sample should be sufficient for subsequent analysis. The sample quantity should be determined in light of the specific parameters to be analyzed and the methods of analysis used.
Fourth, the timing of sample collection should be determined in accordance with the water quality characteristics of the water body, the purpose of the analysis and other factors which may influence the accuracy of the analysis results.
Finally, the sampling plan should ensure that the samples are collected, handled and stored in a proper manner to prevent contamination and degradation of the samples.
Conclusion
The design of a sampling scheme for water quality analysis according to GB 12997-1991 requires careful consideration of the representative sampling points, the quantity of sample collected and stored, the timing of sample collection, and the procedures for preventing contamination and degradation. This document serves to provide technical guidelines for the selection and design of sampling schemes for water quality analysis in accordance with GB 12997-1991.
