Water Pollution Detectives
Name:
Purpose: In this lab you will combine your mapping skills with your knowledge of
streams to locate the source of stream pollution.
Materials:
Ruby Ridge Topographic Map
$5,000
Chemplate
Universal Indicator solution
Background:
The town of Granite City has had an unexpectedly high level of rare illnesses. This town
gets most of its drinking water from the Granite River. Local scientists test the water for
a variety of pollutants. Although most of the levels appear to be within the normal / safe
range the Hexavalent Chromium levels are too high. Some tests read levels of about 0.1
ppb (parts per billion).
Granite City is down stream of an active heavy metal mining area. Molybdenum, Gold,
and Silver are all mined in the area. Hexavalant Chromium is a byproduct of the metal
industry.
Procedure:
1. You work for a state funded environmental protection agency. Study the map and
complete the Environmental Protection Proposed Study Sheet.
Environmental Protection Proposed Study Sheet
Procedure Continued:
2. Begin testing river bottom sediment samples and record your results. You are
trying to locate the exact location of where the Hexavalent Chromium is getting into
the river water. Your budget is set at a maximum of $5,000 for water testing. Every
sample of river sediment costs you $500.
Color
Yellow
Blue
Blue-green
Red
Concentration Range for Hexavalent
Chromium in PPB
<0.1
0.1 – 1.0
1.1 – 10.0
>10
Record your results below:
Test Site #
Color
Concentration Range
Complete your Environmental Protection citation data sheet:
Date:
Field agent Name:
This report is herby given to the landowner of mining site #_________ in
the Ruby Ridge Mining District. As a result of our agency’s inquest
regarding the cause of Hexavalent Chromium pollution in the water
supply for the town of Granite City we have pinpointed a dangerously
high level of pollution in the river sediment downstream of your mine.
Our tests indicated a level of _________PPB.
This is an example of what type of pollution? (point or non-point?)