A water test report may look like a long table of numbers where the main task is finding the word 'complies'. However, one general sentence does not always explain what you actually ordered or which water was checked. Read the sample provenance, parameters, units, comparison values used and laboratory notes. This guide helps you understand the document; it does not replace professional health safety assessment.
Start with the sample, not the numbers
Check the site name, sampling date and location. 'Borehole water' may mean a sample at the source or in the kitchen after several filters. These answer different questions. If the location is too broadly described, clarify the sampling history. Do not reconstruct it later from memory alone, particularly when several containers were submitted together.
Also review who collected the sample and the sampling information supplied. Laboratory analysis and sample collection may have different scopes. An owner-collected sample must not be presented as a professional sampling service. This distinction does not make the result worthless, but helps establish the document's limits and traceability correctly.
The parameter name matters more than a familiar shorthand
Total iron, dissolved iron, total hardness and calcium concentration are not automatically the same. Do not copy only the number or abbreviate the name until its meaning changes. If the equipment selector needs a particular parameter, ask them to state it clearly before ordering the test. This avoids another sample merely because the task was understood differently.
NMVRVI testing information lists different chemical, microbiological and sensory parameters. Testing one set does not automatically confirm every other property. If you ordered analysis for filter selection, check whether it also assessed what matters for drinking and food preparation. A programme name must not replace the specific list of parameters ordered.
Units must match
Milligrams and micrograms per litre differ by a factor of one thousand. For the same substance expressed on the same basis, 0,2 mg/l corresponds to 200 µg/l. This is only a conversion example, not a permitted value for every parameter. The result and its comparison limit must use identical units; otherwise even a simple comparison may be wrong.
Other units may require more than a factor of one thousand. Degrees of hardness, molar expression and mass equivalents have specific definitions. A nitrogen compound's concentration and the same compound expressed as nitrogen are not automatically identical numbers either. If notation in the report or a foreign source differs, confirm the conversion with a specialist.
What does 'less than' mean?
A less-than sign usually relates to the laboratory's detection or quantification capability, but its exact meaning is explained in the specific report. It is not necessarily mathematical zero. Do not delete the sign when transferring the result into a table. The number without it may convey a completely different impression of the concentration found.
If such a notation is near the comparison limit or its interpretation is unclear, contact the laboratory. Do not assign half the limit or zero yourself merely to make a spreadsheet accept the field. Preserve the original information. Practical decisions need a correctly understood measurement, not a neatly completed table.
Comparison values have context
A laboratory may state the applicable standard, its version and a specific value. Check what its conclusion applies to. An indicator parameter, health safety criterion and manufacturer's technical requirement must not be combined into one concept of a 'limit'. A product's requirement for a particular water property does not make it a general legal drinking water limit.
WHO drinking-water quality guidelines provide an international framework for risk management, but do not automatically replace Lithuanian legislation. A value found on a foreign website cannot simply be transferred into a local report. Discuss the application of specific parameters and unclear conclusions with the laboratory or responsible specialist.
One satisfactory line does not confirm everything
If nitrate does not exceed the comparison value used, that says nothing by itself about an untested microbiological condition. Clear water with little iron does not remove other chemical risks. The report's conclusion must reflect the actual programme performed. Avoid sharing only a cropped favourable line when the full document contains additional notes or unfavourable results.
Timing matters too. A test before repairs and a result afterwards describe different conditions. An old report may be valuable history, but is not an indefinite guarantee. Following flooding or another significant event, assess the need for additional testing separately. The document's date is part of its meaning, not a formal decoration.
How should you compare several tests?
Create a table with the original parameter name, unit, result and sampling location. Keep consistently converted values in an additional column, not instead of the original. Add work carried out between tests, filter maintenance and important circumstances. Changes will then remain visible with their context rather than detached from the system's history.
If results differ substantially, first ensure the same point and a similar sampling procedure are being compared. Only then consider changes in the source or treatment. Two randomly collected samples may concern different things. In a dispute, a professionally planned repeat test is often more valuable than choosing the report you prefer.
Document version
If the laboratory issued a corrected report, keep a clearly marked final version and do not circulate the earlier one without explanation. A correction may concern the description or other significant information. Base the decision on the document the laboratory actually approved.
What should you provide for a consultation?
Send the complete anonymised document, retaining necessary technical fields and notes. State your question: suitability for drinking and food preparation, filter selection or equipment performance checks. The filter guide will help prepare the technical information, and in an enquiry you can provide the system schematic. A clear question enables a more precise answer.
A report is useful when we know what it measures and what it does not confirm. Keeping the sampling history, using correct units and obtaining a professionally explained conclusion support responsible decisions. The words 'good' or 'bad' alone do not replace that information.
Information sources
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