Crowd the Tap Maine builds a picture of water quality in an area by collecting samples from many different “taps,” or faucets. By collecting samples from many different taps, we can build a picture of what is happening in a water system. This post describes how collect information about a single tap.
Students will collect 3 different kinds of information about water quality from each tap:
- Information about water chemistry — collected using test strips.
- Information about Total Dissolved Solids (TDS) in the water — collected using a TDS meter.
- Qualitative information about the water — what the student can see and smell, and if the water is part of a public system that is supposed to be safe to drink, how it tastes.
They will record their observations and measurements on paper data input forms. Later, they will transfer the data about each tap from these forms to the shared data repository so that they can look at data from all the taps. We describe how to enter the data into the online system in another post — this post just focuses on the paper data forms. The students will need three input forms for each tap — one for each kind of data. Here are links to PDF copies of each form.
Each of these datasheets asks for a Building ID, Tap ID, and Observer ID. These are identifiers for students and the different buildings where the students are collecting water samples. IF THE STUDENTS ARE COLLECTING SAMPLES FROM A BUILDING BEFORE THE ID IS SET UP, that OK — just give the student a temporary (and unique) ID to use for that building and tap. The actual ID information should be used when entering the data online.
Below are instructions for collecting each of these kinds of data. These instructions are also available as a printable (PDF) version that you can distribute to students on paper or electronically.
- Student Instructions – Water Chemistry
- Student Instructions – Total Dissolved Solids (TDS)
- Student Instructions – Water Quality
In addition, it is useful for students to have the General Instructions, which provide space for them to keep track of their Observer IDs, Building IDs, and Tap IDs.
Collecting Water CHEMISTRY Information (Test Strips)
Repeat these steps for each additional tap that you are collecting data for in your building. NOTE: Be sure to use a new water chemistry strip and Water Chemistry Datasheet for water testing from each tap. ALSO: Please keep your test strip sealed in a ziplock bag until you are ready to use it. If it’s exposed to moisture in the air, it won’t work when you collect your tap water data.
- Complete the first page of the Water Chemistry Datasheet, filling in the Building ID, Tap ID if there is one, your own Observer ID, the Date of Observation and your teacher’s name.
- Fill a clean glass cup or jar with water from your primary tap. Be sure to collect enough water to cover all the squares on the test strip..
- HINT: Do not let the water run from the tap before collecting it. Try to get the water as it first comes out of the tap.
- Holding the test strip by the “handle” (end with no squares), dip the test strip in the water for 5 seconds.
- HINT: Make sure all of the squares on the test strip are submerged in the water.
- Remove the test strip from the water and lay it flat (horizontally) for 60 seconds without shaking or wiping excess water from the strip.
- Lay the test strip flat on the black box on the Test Strip Data Sheet (the one with the picture at right). Be sure to line up the test strip squares with the legend boxes on the data sheet, and have the “handle” at the bottom.
- Compare each test strip square to its corresponding legend to find the closest matches. Record the corresponding number (1-7) in the blank box for each item.
- HINT: Do your best matching the colors. Sometimes there won’t be an exact match. Choose as close as you can.
- On the water chemistry table, circle the corresponding value for each item.
- Take a photo of the test strip and completed legend.
Total Dissolved Solids (TDS)
- Complete the top of the TDS Datasheet, filling in the Building ID, Tap ID if there is one, your own Observer ID, the Date of Observation and your teacher’s name.
- If you have completed Water Chemistry testing, use the same tap water sample to complete these observations. Otherwise, draw fresh sample.
- Remove the protective cap from the TDS meter.
- Press the ON/OFF button to turn the meter on. The tester will read “0.”
- HINT: If the meter doesn’t read “0,” press the CLEAR button.
- HINT: Be sure the meter is reading in “ppm” (parts per million). If not, press the MODE button until it shows “ppm.”
- Immerse the meter into the tap water in your glass or jar no more than 5 cm (2 inches).
- Wait for the display to stabilize (10-30 sec). The meter automatically compensates for temperature variations.
- Once the readout stabilizes, press the HOLD button to view out of the water. Record your readout on the TDS Datasheet.
- IMPORTANT: Once you have recorded your readout, press and hold the ON/OFF button to turn off the meter.
- Please turn off the meter (to save its battery). It will shut off automatically after 10 minutes of non-use, but we don’t really want to count on that.
- Repeat these steps for each additional tap that you are collecting data for in your building. NOTE: Be sure to CLEAR the TDS meter for water testing from each tap.
- Complete a different TDS Datasheet for each tap that you are reporting data for in your building.
- When you have completed your data collection, dip the pin electrodes of the TDS meter into rubbing alcohol for 30 seconds. Then wipe down the outer casing of the TDS meter with rubbing alcohol or a sanitizing wipe.
- HINT: Try not to handle the TDS meter with your bare hands after you have cleaned it!
- RETURN the TDS meter to your teacher for another student to use.
Water Quality (Observations)
- Complete the top of the Water Quality Datasheet, filling in the Building ID, Tap ID if there is one, your own Observer ID, the Date of Observation and your teacher’s name.
- If you have completed Water Chemistry testing, use the same tap water sample to complete these observations. Otherwise, draw fresh sample.
- Look at the sink and other fixtures for stains.
- You will collect observations and take photos as needed for your primary tap water, including:
- Taste
- Odor
- Color
- Stains around fixtures
- Particles
- Take your time with these observations. They can provide powerful evidence that there are problems with the water. Often, they will be more reliable, as evidence, than the data that you gather with test strips.
- Record your observations on the Water Quality Datasheet.
- Repeat these steps for each additional tap that you are collecting data for in your building.