Turbidity was not measured in samples from Boulder Canyon and downstream from 1998-2000; it was considered similar enough to total suspended solids (TSS) to not warrant an additional analysis. Analysis of turbidity for these sites began in January 2001. Therefore, an analysis of the stream profile can not yet be done.

There are turbidity data for the source water sampling sites (e.g, Middle Boulder Creek above the Barker weir (MBCaW) and North Boulder Creek at Lakewood Reservoir (NBC-Lw). Turbidity at these sites generally ranged from zero to 4 nephelometric turbidity units (NTUs). Turbidity often increases during spring runoff, because faster moving water can carry more sediment (see NBC-Lw in 1999.

Turbidity regulations established by the U.S. Environmental Protection Agency (EPA) vary depending on individual water treatment systems. For those regulations, see the U.S. EPA Office of Water’s Current Drinking Water Standards; http://www.epa.gov/safewater/mcl.html)