539. 



STATE OF WASHINGTON DEPARTMENT OF FISHERIES - EXHIBIT E 



4. Turbidity 



Marine and estuary 



Turbidity for marine and estuarial waters^ 

 upper 10 meters (32c 5 ft) to be based upon vertical ex- 

 tinction coefficient. Standards should be coastal 

 maximums as listed in Table 22, p. 84 and by Figure 20, 

 p. 85, The Oceans , Sverdrup, Johnson, and Fleming, 19^6. 

 A Secchi disc may be used for determination of vertical 

 extinction coefficient using the ratio of 1.7 divided 

 by Secchi disc reading (Secchi disc reading in meters 

 for a 30 centimeter diameter white disc) for blue light 

 as developed by Poole and Atkins, 1929^ Journal Marine 

 Biological Association, United Kingdom (I6). 



No material should be added to the water 

 that causes the extinction coefficient to become larger 

 than the standard values as given in the above references. 



In the deeper waters (mid-depth and bottom 

 samples) Jackson Turbidity Units should be less than 25 

 attributable to materials resulting from man-made activities. 



Dredging operations should be planned to 

 take into account the seasonal cycles of flow and turbidity 

 so as not to exceed the proposed standards. 



Fresh water 



Jackson Turbidity Units (JTU) of less than 



