Field Monitoring Of Surface Water Quality
- Time Span:
1 day per collection group (note this time may vary greatly depending on the location of
- Brief Description:
Students go to a field collection site (pond, stream, drainage ditch etc...) and collect
GPS coordinates, site data, water samples, and benthic macroorganisms for analysis of
the overall quality of the sampling body.
- Students will collect samples (water, biological) using proper sampling techniques.
- Students will use GPS units for the aquisition of sampling coordinates.
- Students will study the watershed and surrounding ecosystem of the sampling body.
- tape measure, thermometer, GPS unit, stopwatch, perforated plastic golf ball, buckets,
collection vials, dip net, latex gloves, boots/waders, digital camera, calculator
The following directions are for the Water Quality Field Information sheet
adapted from the Illinois River Watch Program. It focuses on streams but can be adapted to fit any body
Collecting and Sampling:
- Choose a collection site that is a total length of 100 feet.
- Mark the site at the 0, 50, and 100 feet locations with flags.
- Document the site by taking digital photos and panoramas.
- After choosing and marking the collection site record the date of collection, stream name, watershed name,
- Using a GPS unit(or a topo map if a GPS is unavailable) determine and record the longitude and
latitude of the site.
- Record information on present weather, weather in the past 48 hours, water appearance, water odor,
turbidity, and temperature of the air and water.
- Estimate the following information: algal growth, canopy cover, bottom substrate, and
embeddedness. (For specifics, see the Water Quality Field Information sheet.)
- Calculate the stream discharge using the following steps.
- Measure the width of the stream and take depth measurements of the stream at the following locations:
stream bank nearset to you, middle of the the stream, and the far stream bank. Note: to take depth measurements
a pole or broom handle marked with graduations is sufficient. Average the depth measurements.
- Calculate the velocity (velocity=distance/time) of the stream by releasing a plastic golf ball and timing how long it takes to travel 10 feet.
Release the golf ball at the locations where the depth measurements were taken. Average the velocity measurements.
- Use the formula Discharge=(stream width)(average depth)(average velocity) to calculate the discharge of the stream.
- Describe the watershed features i.e. is the watershed a forest, grassland, golf course etc...
- Note the presence of any upstream dams or wastewater discharge.
- Record the presence of drainage pipes in the study site and note any channel alteration.
You will need to follow the specific guidelines of the chemical tests that you are running when collecting water samples. For example,
many dissolved oxygen tests require you to fix the water immediately. Good sampling techniques include the use of latex gloves and
keeping the samples in a cooler of ice until the tests are run in the lab. The following steps describe how to collect macroinvertebrates
usind a dip net.
- Choose two stream habitats (riffle, leafpacks, snag areas, undercut banks, and sediment) to collect samples.
- Place the dip net upstream of the habitat.
- If sampling from a riffle or sediment, plant the heel of a boot 12 inches in front of the net and twist to kick
sediment and debris into the net.
- If collecting from a leafpack, drag the dipnet through the leafpack collecting leaves and debris.
- To collect from a snag area or an undercut bank, drag across the snag or bank with the net to collect debris.
- After collecting the samples, examine the dip net carefully for mollusks. If they are found, identify them, record the number found and
return them to the stream. Place the remaining organisms and debris into a bucket containing water from the collection site.
- Upon returning to the lab, aerate the buckets with the biological samples until you are ready to use them.
Return to Field and Lab Activities.