The Hanalei community, through the development of a Watershed Action Plan, determined that reduction of sediment loading to the Hanalei River and Bay was of high priority. The Hanalei Watershed Hui, with equipment on loan from the Environmental Protection Agency, is testing for turbidity at 6 sites along the Hanalei River, 8 agricultural ditches, 1 drain from a wildlife pond, three site in the Hanalei Bay, and Waioli, Waipa, and Waikoko Streams. Weekly samples are being collected and immediately analyzed for turbidity, reported in nephelometric turbidity units (NTUs), the standard for turbidity reporting.

The Hawaii State Standards for turbidity are as follows:

STREAMS--FRESH WATER (Where Salinity is less than 0.5 o/oo)
Wet Season (November 1 through April 30)
Geometric mean not to exceed 5.0 NTU
Single values not to exceed 15 NTU 10% of the time
Single values not to exceed 25 NTU 2% of the time
Dry Season (May 1 through October 31)
Geometric mean not to exceed 2.0 NTU
Single values not to exceed 5.5 NTU 10% of the time
Single values not to exceed 10 NTU 2% of the time

ESTUARIES-(Where Salinity is greater than 0.5 o/oo)
Year Around (January 1 through December 31)
Geometric mean not to exceed 1.5 NTU
Single values not to exceed 3 NTU 10% of the time
Single values not to exceed 5 NTU 2% of the time

The Geometric Mean is defined as: A measure of central tendency calculated by multiplying a series of numbers and taking the nth root of the product, where n is the number of items in the series. The geometric mean is often used when finding an average for numbers presented as percentages.