A Water Quality Project in Interior Alaska, 2009
Shelby is a Gwich’in from Beaver. Her father's family is from Chalkyitsik. She travels to Chalkyitsik to visit her relatives during the summers (see image below for locations). During the Summer 2009 trip, she collected water samples from the Porcupine and Black rivers with her family (June). She also collected: (1) safewater (drinking water) samples from the Beaver facility in September; (2) a Yukon River sample in October; (3) a purified water sample in November; and (4) a snow sample which was melted (December).
Shelby with her project at the Annual Interior AISES Science Fair.
Shelby measured the conductivity and total dissolved solutes using a Conductivity/TDS Meter provided by the Nenana River Project. She also filtered her samples to determine the suspended sediment load (these are the same measurements that Sam is making on the Nenana River).
She presented her results at the Annual Interior American Indian Science and Engineering Society (AISES) Science Fair which was held at the Interior Aleutians Campus at the Harper Building at the University of Alaska Fairbanks..
Shelby won the overall prize with her water quality project. She received $1,000.00 to travel to the National American Indian Science and Engineering Fair in Albuquerque, New Mexico on March 11-13, 2010!
Shelby placed 2nd in her division of Environmental Sciences at the National AISES science fair. Her project received many encouraging comments and she is looking forward to gathering more data this coming summer for a future science project.
Shelby measured three variables to determine the quality of her water samples:
- • Water Conductivity - is directly related to the concentration of dissolved ionized solids in the water (the higher the dissolved ion concentration the higher the conductivity). The ions allow the water to conduct an electrical current. This is measured with a Conductivity/TDS meter in milliSiemens (mS).
- • Total Dissolved Solids (TDS) - the measure of the combined organic and inorganic matter present in a liquid. In this case, this value was measured using a Conductivity/TDS meter in parts per million (PPM) which is the same as mg/kg (~mg/L). Because this instrument only detects charged particles it is really only detecting dissolved ions (not uncharged particles including many organic compounds).
- • Total Suspended Solids (TSS) - the concentration of solid-phase material suspended in a water-sediment mixture measured in milligrams per liter (mg/L). This values is determined by filtering a known volume of a well-mixed water sample.
| Water Source | Conductivity (mS) | TDS (PPM) | TSS (mg/L) |
|---|---|---|---|
| Snow sample | 0.000 | 0 | 7.096 |
| School Purifier | 0.000 | 7 | 7.032 |
| Black River | 0.204 | 136 | 7.112 |
| Porcupine River | 0.205 | 138 | 7.068 |
| Yukon River | 0.373 | 249 | 7.108 |
| Beaver Safewater | 0.593 | 397 | 7.108 |
The Clean Water Act of 1977 defines good water quality as TDS values of 300 to 600 mg/L and fair quality water quality as TDS values of 600 to 900 mg/L. Water that has a TDS content >900 mg/L is unacceptable and not recommended for consumption.
Shelby's null hypothesis is:
There is no difference in quality between her water samples.
Project Details
Nenana River Project
Monitoring the freeze-thaw cycle of the Nenana River
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