Use of Transparency Tubes for Rapid Assessment of Total Suspended Solids and Turbidity in Streams

ABSTRACT

Studies were conducted to evaluate the use of transparency tubes to predict total suspended solids concentrations (TSS) and NTU turbidity in streams. Linear regression of data collected from 29 sample stations (12 streams) in northeast Ohio revealed a highly predictive correlation for both parameters using the Ohio Sediment Stick^o. Laboratory studies showed significant differences between water clarity readings among individual observers using the Ohio Sediment Stick^o. The type of visual end point target used in the tube had no effect on water clarity readings. A table to predict TSS concentrations based upon water clarity was developed for the Ohio Sediment Stick^o. A comparison of three tubes of differing design (e.g., Minnesota Pollution Control Agency tube, NOAA GLOBE tube, and Ohio Sediment Stick^o) found no significant differences in the relationship of water clarity measurement vs. TSS concentrations or NTU turbidity among tubes. Our data indicate that predictive equations developed for the Ohio Sediment Stick^o can be applied with statistical confidence to both the MPCA tube and the NOAA GLOBE tube. When appropriately used, transparency tubes can be an effective and inexpensive monitoring tool to estimate relative sediment loads to lakes from different watersheds.

Key Words:

• transparency tube
• NTU turbidity
• non-point pollution
• total suspended solids
• volunteer monitoring
• streams
• Ohio Sediment Stick^o
• MPCA tube
• NOAA GLOBE tube