How To Read A Lab Analysis Report

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For the Bottle Site samples (both Surface and Reservoir), you will see a set of two tables such as those below. The first table provides the lab results from the analysis of metal levels in water samples. The second table provides the lab results from the analysis of total dissolved solids, alkalinity, and anionic salt components. Each of the descriptions contains a brief explanation of the table value, with a link to page containing more detailed information about each element or compound.

Note that each column title has a set of up/down arrows next to the title. This allows you to sort the table (ascending/descending) should you wish to do so. At the bottom of each numerical value column, there is a value (in bold) that is the calculated average (or mean) of all the values in that column.

Metals Report

Columns: All metal concentration values are given in units of parts per million (ppm).

  • Site ID:
  • Ca: Calcium. Naturally occurring element from limestone (principle mineral is calcium carbonate, CaCO3) and other geologic forms. The Ca2+ ion, along with magnesium (as Mg2+) and other divalent cations (metals with +2 charges), are responsible for water hardness.
  • Mg: Magnesium. Naturally occurring element from different minerals (e.g., dolomite, epsomite) in geologic layers. A contributor to water hardness.
  • Fe: Iron. Naturally occurring element in various minerals, rust (iron oxide, Fe2O3), and coal deposits. Iron levels are particularly elevated in streams affected by abandoned/acid mine drainage (AMD), where a dark yellow to light orange sediment might be found, consisting primarily of iron (iii) hydroxide, Fe(OH)3.
  • Mn: Manganese. Naturally occurring element in various minerals and found frequently with iron. Levels are typically much lower than iron levels. Like iron, manganese is elevated in streams affected by AMD.
  • Al: Aluminum. Naturally occurring element in various minerals, but usually at very low levels. Higher aluminum levels can occur from areas affected by coal extraction activities, and highest levels are usually the result of AMD presence.
  • Sr: Strontium. A "heavy metal" present in various geologic strata, including radioactive isotopes. The presence of strontium in water usually signifies the presence (recent or past) of coal and/or natural gas extraction activities and fallout from coal burning power plants.
  • Pb: Lead.
  • As: Arsenic.
  • Hg: Mercury.
  • Cr: Chromium.
  • Ba: Barium.
  • Cd: Cadmium.

Means: At the bottom of each column, the average column value is displayed.

Site ID Ca Mg Fe Mn Al[1] Sr Pb As Hg Cr Ba Cd
R-01 29.0 5.77 <LQ 0.265 0.090 <LQ <LQ <LQ <LQ 0.017 <LQ
R-02 28.6 7.53 <LQ 0.242 0.088 <LQ <LQ <LQ <LQ 0.019 <LQ
R-03 30.5 7.78 <LQ 0.227 0.096 <LQ <LQ <LQ <LQ 0.036 <LQ
R-04 27.2 7.21 0.10 1.730 0.086 <LQ <LQ <LQ <LQ 0.032 <LQ
R-05 24.1 6.73 <LQ 0.028 0.077 <LQ <LQ <LQ <LQ 0.028 <LQ
R-06 24.9 6.88 <LQ 0.022 0.078 <LQ <LQ <LQ <LQ 0.026 <LQ
Means =

TDS, Alkalinity, and Salts Report

Columns: All concentration values are given in units of parts per million (ppm). Alkalinity is reported as ppm CaCO3 (calcium carbonate).

  • TDS: Total Dissolved Solids.
  • Alkalinity: A measure of the acid-neutralizing ability of the water. The lower this value, the more acidic the water tends to be. For streams heavily impacted by abandoned/acid mine drainage (AMD), alkalinity is non-existent and reported as "acidic".
  • F-: Fluoride ion. The anion of the element fluorine.
  • Cl-: Chloride ion. The anion of the element chlorine.
  • Br-: Bromide ion. The anion of the element bromine.
  • NO3-: Nitrate.
  • PO43-: Phosphate.
  • SO42-: Sulfate.

Means: At the bottom of each column, the average column value is displayed.

Site ID TDS Alk. F- Cl- Br- NO3- PO43- SO42-
R-01 190 35.15 0.10 47.60 0.33 2.45 0.32 53.84
R-02 62 39.75 0.15 43.88 0.30 2.90 0.31 54.17
R-03 96 52.27 0.04 44.38 0.46 2.82 0.31 49.83
R-04 251 43.92 0.11 49.91 0.57 3.17 0.28 47.12
R-05 200 35.57 0.17 42.99 0.62 2.42 0.28 42.88
R-06 149 43.92 0.09 38.44 0.31 1.97 0.29 47.76
Means =

Summary Lab Reports

In addition to the quarterly lab reports, each surface site and reservoir site has a summary report (e.g., Site 01) that shows all lab results for only that site over the all sampling quarters. Each analyte is explained above. The only different for the summary reports is that both field and lab data is shown, and each row has a link to the quarterly report. Finally, at the bottom of each data column we report both the mean and standard deviation values when applicable.

Note: Each table column reports raw field or lab results. However, the means and standard deviations may have different numbers of decimal places. The reason for this is that we typically only report the mean value to the same number of decimal places as the first digit in the standard deviation value. Reporting any more precision than the first digit doesn't really mean much. For example, chloride values are reported to the nearest 0.01 ppm. However, due to the wide range of chloride values over different seasons or years, the mean may be reported as 45 ± 10.

Notes

  1. Samples were not analyzed for aluminum prior to June 2014.



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