scope:

General 

This standard describes two methods for evaluating water quality for subsurface injection: Procedure A-rate versus cumulative volume test (for water-quality monitoring) and Procedure B-suspended solids test (for diagnosis or monitoring). The methods describe the apparatus required, test conditions, test procedures, reporting procedures, and supplementary tests. Interpretation of the results is beyond the scope of this standard. The bibliography supplies sources of interpretation methods. 

Before a test program is selected, the user should determine an appropriate criterion for evaluating the test results. For example, if the intent is to use membrane filtration as a simple water control test, the control criterion might be a given slope of the filtration curve. If diagnostic information is required, more emphasis may be placed on qualitative information, such as the shape of the filtration curve, or spot tests on the filtered suspended solids as well as visual examination of the filter immediately after the test. 

Membrane filtration may be used to monitor pickup of suspended solids from the formation, in which case quantitative determination of suspended solids on the filter may be the selected criterion. Each situation should receive an appropriate review of the parameters involved.

The injection behavior of subsurface formations varies widely, and results of water-quality tests apply only to the system being tested. Applying the results obtained by these tests, therefore, is influenced by the requirements of each subsurface injection project. This standard should be used for routine water quality monitoring problem diagnosing, evaluating system changes and upsets, and chemical treatment monitoring. The manner in which the test results are used depends on the specific injection system requirements.

This standard is applicable when the water sample is representative in the system of interest. This standard does not imply that any results or their interpretation may be arbitrarily applied to other water injection projects.