Raw Water Quality - What's considered High Turbidity & Colour

[tipp79]

A lot of guidance I've read for sludge production refers to highly turbid & highly coloured raw waters. What would people consider the limit above which a raw water source could be considered highly turbid or coloured. For colour, I was thinking over 100 Hazen but I've seen raw waters with higher colour as well. Thanks

 

[bimr]

Colors below 10 would not usually be observed in a tumblerful but could easily be detected by comparing with color standards.

Colors above 20 would be noticeable in a tumblerful and waters much above this would be considered high in color.

Since color is derived from decaying vegetation, most of the highly colored waters originate in swampy regions. The majority of such waters are usually very low in turbidity but this is by no means always the rule.

Turbidity is not an exact determination of the mass of the suspended particles. Instead, it is a measure of the opacity as compared with certain arbitrary standards; this differs with varying materials and degrees of fineness. Turbidity of a given water will also vary over time. Certain fixed features such as the distance from shore, the intake depth, and the part of the lake or stream where it is located will affect the turbidity.

My opinion is that waters with turbidities above the range of 700-900 would be considered to have high turbidity.