A stack of several examples of analytical sample test results

The department handles a massive amount of reports and documents every year. Some of these documents include sample analysis results, diagrams and graphs. If you are not familiar with the terminology or how to interpret the data, these documents may be confusing, leaving you with more questions than answers. Below are some examples of reports and documents that explain the information that is provided in those reports. 

Interpreting Sample Analysis Results

Different laboratories produce reports that can vary greatly in appearance and in the order of information included. Despite the differences in format and presentation, they all contain certain elements. In sample analysis reports, the amount or concentration of a particular substance detected in the sample can be reported in several units of measurement. You may see parts per million (ppm), which can also be expressed as milligrams per liter (mg/l) or milligrams per kilogram (mg/kg). Another common unit is parts per billion (ppb), which is also expressed as microgram per liter (µg/l) or microgram per kilogram (µg/kg). In drinking water results, you may also see parts per trillion (ppt). To visualize what these expressions actually mean, one ppm would be equal to one drop of ink in a 10-gallon fish tank. One ppb would be equal to one drop of ink in a 10,000-gallon swimming pool. One ppt would be equal to one drop of ink in 20 Olympic-sized swimming pools.

The department compares the results from the sample analysis reports to regulatory limits established by the U.S. Environmental Protection Agency (EPA). These limits go by different names, depending on what media — air, soil, sediment, surface water, groundwater and drinking water — the substance is detected. The same substance may also have different limits, depending on the media in which it is detected. These limits represent the highest amount of a specific substance allowed to be present in that media, which does not pose a substantial threat to human health or the environment and can be achieved using the best available technology.




Reading Maps and Diagrams

Diagrams, charts and maps present information visually, whether summarizing information from data or text or illustrating a complex process or other element. The department works with various types of maps, including geologic, topographic and geospatial maps and 3-D modeling. Understanding how to read these visual aids is a very efficient way to understand the data being presented. 

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