Sunday, February 23, 2014

Water Quality Testing after Torrential Rains

On 2/18/14, after days of heavy rainfall, the River Spies conducted water quality testing at three locations in the Amazon Creek Headwaters. The water was so turbid that we could not even see the Secchi disk at the bottom of our sample jars! After collecting our water samples and recording temperature and turbidity, we headed for drier ground (Edison Elementary) to test dissolved oxygen and pH.
Stars and suns mark our sample sites thus far. Edison Elementary is circled in red.
The water temperature was 6°C at our southernmost site and 8°C at our two other locations.  The two degree difference shows how much tree cover and shade can affect stream temperatures. Turbidity readings were off the charts - at least 100 JTU. The pH was 8.0 and the dissolved oxygen was 4ppm at all sites.
Fox Hollow Trail
Later, I entered our data on to the World Water Monitoring website: http://www.monitorwater.org/default.aspx



Saturday, February 22, 2014

Fresh Water Availability & Jelly Marbles

On 2/11/14, the River Spies grew jelly marbles, examined fresh water availability, and discussed ways to keep our waterways clean.


The River Spies hold up fresh water test strips.
Jelly marbles are made of a super absorbent polymer that expand to many times their original size when immersed in water. Super absorbents hold so much water that farmers use them to preserve crops during times of drought. Clear jelly marbles "vanish" in water; since they are 99% water, they refract light almost identically.

Jelly Marbles!
We explored fresh water availability by adapting an activity from Project WET called "A Drop in the Bucket." We used a 1000ml graduated cylinder to represent all the water on Earth. We took away 97% of that water (or 970ml) that is salt water. Of the 30ml remaining fresh water, 80% (or 24ml) is frozen at the poles. Of the remaining 6ml of fresh water, only .03ml - about a drop - is potable. The rest is either trapped underground or polluted. That one single drop hitting an empty bucket really drives home the necessity of protecting our fresh water resources! 


Near the end of our session, the River Spies split into pairs to think of ways that they could encourage people to protect our waterways. A few minutes later, we reconvened to share ideas. My favorite suggestion was posting signs warning people that they would be fined an octillion dollars for littering!

Sunday, February 9, 2014

Water Quality Testing near Amazon Park

The River Spies pose creekside.

On a chilly and rainy 2/4/14, the River Spies conducted water quality testing in Amazon Creek near Amazon Park. The River Spies maintained a positive attitude despite inclement weather and they even sang an impromptu tune about cold hands and feet!

Marley holds a cold water sample!
We measured water temperature, pH, turbidity, and dissolved oxygen. The water temperature was 6°C with a turbidity reading of 40 JTU. The pH was 7.5 and the dissolved oxygen was 4ppm (32% saturated). The River Spies are improving their survey techniques and are becoming adept at measuring the water quality parameters.

Our Amazon Creek survey site.
Later, I entered our data on to the World Water Monitoring website: http://www.monitorwater.org/default.aspx



Sunday, February 2, 2014

Water Cycle Terrariums

On 1/28/14, the River Spies constructed terrariums to model the global water cycle. We used plastic bottles to represent the atmosphere and gravel for Earth's rocky crust. 


The River Spies construct their terrariums.

The River Spies layered soil, twigs, leaves, bark, and plants on top of the gravel and then poured in some water. Some hapless slugs and worms were trapped in the process but we later released them back to the school garden! We had to artificially speed up the evaporation process by applying heat from a hair dryer. Almost immediately the River Spies could detect condensation forming on the inside surface of the terrarium and then beads of water running down the bottle (precipitation). The terrariums are an excellent way to demonstrate the main components of the water cycle in a closed system: evaporation, condensation, and precipitation. 
For step by step instructions on how to build your own terrarium, check out this link: http://www.fairchildgarden.org/uploads/docs/Education/Downloadable_teaching_modules/school%20gardens/Terrarium%20Activity.pdf








We also explored the concept of percent saturation by soaking a sponge in water. (The River Spies measure percent saturation of dissolved oxygen as one of our water quality indicators). We first saturated a sponge to 100% and measured the amount of water it held by squeezing the water into a graduated cylinder. The River Spies then took turns trying to figure out how to saturate a sponge to just 50% of its capacity.