Turbidity is a measure of the cloudiness of water, which is due to suspended solids.  Higher turbidity levels are generally associated with higher levels of disease causing microorganisms.  When designing a filtration unit, turbidity should be taken into account because sediment can build up and clog the system over time.

Acceptable Level:

According to the U.S. EPA National Primary Drinking Water Regulations, turbidity can never exceed 5 NTU (Nephelolometric Turbidity Unit).

Test Materials:

Turbidity Test Kit (two tubes and standard reagent)

Where to Buy Materials:

- Acorn Naturalists – sells a “Turbidity Test Kit” for $60 and standard turbidity reagent refills for $10.  http://www.acornnaturalists.com – search “turbidity”

Directions:

1.  Fill one tube with 25mL clean water and one tube with 25mL sample water.
2.  Add drops of standard turbidity reagent until both tubes look the same.
- the bottom of each tube has a black dot on a white background, look down the tubes at this dot to compare them.
- count the number of drops added
3.  Determine the JTU (Jackson Turbidity Unit) value from the number of drops added.
- Different standard reagents with have different concentrations, read the bottle for proper drop to JTU correlation.
- 1 JTU = 1 NTU