Summarizing and visualizing large amounts of ambient water quality data can be complex and time consuming. Contour maps provide a way to quickly and easily combine large amounts of data to view the variations in water quality across a geographic area. Each contour represents an estimated range of a particular water quality parameter, based on known values at the stations where data was previously collected. This enables the user to quickly compare water quality of one region to another, gauge the magnitude of a water quality value based on its range within the province, and identify areas of concern that would help guide future monitoring and management activities. Spatial context is another benefit inherent with mapping as knowledge of location may help explain why certain areas have higher or lower readings for a particular water quality parameter. Prevailing climatic conditions, geology, and anthropogenic activity are some examples of contextual information that could help interpret water quality results.
Data collected from multiple sampling programs within the Water Resources Management Division between 1985 -2013 was summarized and analyzed. Care was taken to include only data which was relevant and accurate. The maps are based on median values, and while they do not provide detailed information about the parameters, they can provide a general idea of background ambient values across the province.
The contour regions were estimated using a geostatistical approach known as inverse distance weighting model.
Data Sources:
- Canada – Newfoundland and Labrador Water Quality Monitoring Agreement (WQMA) – Grab Sample Data
- NL Real Time Water Quality Monitoring Network – QA/QC Grab Sample Data
- NL Drinking Water Program – Source Water Grab Sample Data
Cautions:
- The contour maps below are visual representations of summarized water quality data. Detailed analysis should be performed as necessary.
- While care has been taken to produce maps as accurately as possible, working with older datasets and multiple detection limit changes was a major challenge. Minor inaccuracies may still exist.
- Where necessary, parameters or stations have been excluded due to limited data availability as samples reporting as less than detection limits cannot be incorporated accurately.
- Some maps are more accurate than others as they contain more stations with data from which to generate the contours. Maps with less stations will be less reliable for interpolation and should be used with caution.
- Neither the organizations collecting data, nor any person acting on behalf of any of them, assume any liability for the misuse or misunderstanding of the data. The user is expected to make the final evaluation of the appropriateness and accuracy of the data and calculations in his (or her) own set of circumstances. The Government of Newfoundland and Labrador, Department of Environment, Climate Change and Municipalities, Water Resources Management Division will not accept and does not assume any responsibility for information provided by third parties.
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Current Contour Maps – Data 1985 – 2013
| Physical and Chemical Parameters | Major Ions | Nutrients | Trace Elements and Metals |
|---|---|---|---|
| Alkalinity | Calcium (Ca) | Carbon | Aluminum (Al) |
| Colour | Chloride (Cl) | Nitrogen (N) | Antimony (Sb) |
| Specific Conductance | Fluoride (F) | Phosphorous (P) | Arsenic (As) |
| pH | Magnesium (Mg) | Barium (Ba) | |
| Potassium (K) | Beryllium (Be) | ||
| Sulphate (SO4) | Bismuth (Bi) | ||
| Boron (B) | |||
| Cadmium (Cd) | |||
| Cobalt (Co) | |||
| Chromium (Cr) | |||
| Copper (Cu) | |||
| Gallium (Ga) | |||
| Lanthanum (La) | |||
| Iron (Fe) | |||
| Lead (Pb) | |||
| Lithium (Li) | |||
| Manganese (Mn) | |||
| Molybdenum (Mo) | |||
| Nickel (Ni) | |||
| Rubidium (Rb) | |||
| Strontium (Sr) | |||
| Thallium (Tl) | |||
| Uranium (U) | |||
| Vanadium (V) | |||
| Zinc (Zn) |
Archived Contour Maps – Data 1985 – 2000
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