KnowYourH2O Introduces Groundbreaking Online Tool for Global Surface Water Quality Grading

A new online tool called the Water Quality Index Calculator is available from KnowYourH2O that can be used globally to provide a ‘grade’ for surface water quality as part of a watershed monitoring, surface water monitoring and assessment program, citizen science, lake monitoring, or source water assessment tool. We are all familiar with the traditional A, B, C, D, F grading system provided by educational systems globally, but this tool is different! It applies similar ‘grading’ logic to nine specific water quality measurement variables as known determinants of quality.  Unlike previous tools, this tool permits the use to enter secchi depth (disc) reading. Using this logic, we can quantify and grade surface waters in relation to one another across the globe using a standardized set of criteria.

Nine Measurements

The nine measurements include quality data for:

• Dissolved Oxygen
• Fecal Coliform
• pH
• Biochemical Oxygen Demand (BOD)
• Temperature Change From Reference Site
• Total Phosphorus (or Phosphate)
• Total Nitrate (or Nitrogen Units)
• Turbidity or Secchi Depth
• Total Dissolved Solids

What is also unique about this new tool, it does not require all these factors to be available and input to grade the water; however, more accuracy is provided based on the greater number of variables provided. The user also provides location information and whether the data being entered is for test or actual data purposes. This will allow the KnowYourH2O.com team over time to map quality information globally as additional ‘actual’ data is provided.

The calculations that the new KnowYourH2O Water Quality Index Calculator Tool uses are based on the original WQI Calculator that was developed via scientific consensus in the 1970’s by the National Sanitation Foundation (NSF). The calculator page will provide users with the information they need to accurately sample and provide the exact measurements the tool needs for accuracy. In the case of total phosphorus of phosphate – the tool can accept either of these values; however, the user must indicate which is being provided and this is similar for Total Nitrogen or Nitrate. With each input factor a Q-value (quality-value) for each parameter is calculated and applied to the overall Water Quality Index calculation.

A table of other water quality data points is available as a part of the tool in order to allow the practitioner an easy way to keep all water quality data in one place – including factors that may not be used in the overall water quality index calculation. The tool can be added to a mobile device as a part of new app functionality from knowyourh2o.com by scanning the QR code at the bottom of the page.

Water Quality Grades

Once any of the total 9 factors are input (can include 1 input or all 9) – the tool does the work to calculate the following Water Quality ‘grade’ index ranges:

• A Excellent: 90-100
• B Good: 70-89
• C Medium: 50-69
• D Bad: 25-49
• F Very Bad: 0-24

Once submitted to the database, the tool gets to work providing all of the logarithmic curve functions in the background and outputs a Surface Water Quality Index report in .PDF format that can be downloaded and printed by the user. If the user provided any additional surface water quality data – this information is also output on the report.

Since it was released for beta testing in early April 2023, the tool has been used across 33 different countries with 20 countries using the tool also submitting actual surface water quality data that can be used on our Citizen Science Global Map. The historic tool that this replaces was used across over 50 countries, and it is our hope that the new tool with database backend will garner similar reach. As of mid-May 2023 the tool has been used over 1,300 times providing users with a valuable graded data-output report.  

The tool is now available for use by all. Over time it is our hope to add historic data from our archives to this database in order to strengthen the data and analysis values of the tool. We are open to your suggestions regarding other uses of this tool. Some thoughts regarding the future growth of this tool include support via subscription format, ability to input and bulk download reports for data input by a particular user, and expansion of the Citizen Science Global Map around the database behind this tool. Please submit your suggestions here.

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To download the Water Quality Index App for Mobile Devices, scan or click the QR Code below.