Start with the reason for the inquiry
Describe the water source, the sampling location you have in mind and any recent event that led to the concern. If another professional or organization requested testing, provide the original request rather than trying to summarize its technical requirements.
Mention any previous water test, maintenance work or treatment information that relates to the question. Existing records can help explain why you are seeking a new analysis and what you want to compare.
Confirm what is included in the proposed test
For private wells, CDC lists total coliform bacteria among common water-quality tests and explains that indicator bacteria help evaluate possible contamination. It also distinguishes bacterial testing from tests such as nitrate, pH and total dissolved solids. [1] A bacterial result answers the question covered by that analysis; it is not a complete test of every possible substance in the water.
Ask which analysis is proposed, what it is intended to establish and which sample locations are included. Confirm whether the requested test is available for the water source and purpose you described.
Have the proposed scope identify the samples, analyses and report deliverables. Ask how the results will be explained and what questions remain outside that scope. Specific test coverage should be confirmed directly before you authorize the service.
Arrange collection and reporting
Before collecting water yourself, confirm who will collect the sample and what instructions apply. Ask about the required container, collection location, handling and delivery arrangements for the proposed analysis.
Confirm the laboratory that would receive the sample, the expected processing and reporting schedule, and any documentation needed for your intended use. Keep the collection details and final report with the request that prompted the test.
Sources & further reading
These sources support the general guidance. The work at a particular property depends on its conditions and agreed scope.