Characteristics of Treated Sewage

It depends upon the Discharge Consent in the UK, which is the domain of the Environment Agency. Consents vary from place to place dependent upon local conditions.

Depends upon the required standards in your area.

If you are in the USA, look at your NPDES permit. If you don't have one yet, go get one.

In the USA, effluent limits are determined by the type of receiving water and in most cases certain reach or reaches within that water course, and the state regulatory agency determines what the effluent limits will be based on a number of factors, all shown on the NSPES Permit. Not all receiving waters are the same. Ditto regarding the ecology resident in and about the receiving water body that can be effected by sewage effluent and its constituent components. Turbidity is but one limit that must be monitored. There are others, such as, but limited to: BOD5, MLSS, MLVSS, TDSS, TSS, Color, temperature, pH, conductivity, Total Free Chlorine, N, P, CO2......there are others, all depending on the characteristics and makeup of the river, lake, stream, etc. One most not forget about monitoring the effluent for concentrations of chemical compounds, in dissolved or suspended states, if they known to be a primary component in the influent sewage.

I believe you should study up more on this subject using a good standard engineering textbook that deals with wastewater treatment. What comes to mind immediately are the following: "Civil Engineering Handbook" by Merritt, and "Wastewater Collection, Treatment & Disposal" by Metcalf & Eddy.

Hope that helps!

Have a great sunny day!

I am not sure what you mean "Whether turbidity limit plays a major role". In California the $1000 a day fine per violation is the same for any violation (receive a cease and dissist order and it goes up to $5000 a day per violation). I would bet, at least in California and a few similarly self regulated States, the turbidity of the treated effluent has to be substantially lower than the receiving waters you discharge to, unless they are pristine, and your regulatory agency will take exceedance of the limits seriously (or at least the fines they can receive).

The standards are based on individual country regulations.

The tentative or rough guidelines are

1] Colour-10 hazen units

2]pH- close to neutral[6 to 7.5]

3]Suspended solids[ 10 to 20 NTU

4]BOD_30 ppm

5]COD-160 ppm.

6]Toxic ants-cyanide, heavy metals, phenols, formaldehyde, pesticides, carcinogens[0.001 to .01 range]

7]Temperature-below 40 degree centigrades

8]TDS- Less than 2100 ppm.

others-include chlorides, sulphates, phosphates,fluorides, chlorine,Coliform count etc.

The above said factors are mere guidelines and claim no standard of reference.

I suppose you mean treated sewage effluent? (as opposed to industrial effluent)

I've never heard of turbidity being specified in a treated sewage standard. Other posters have given various parameters which might be specified. Suspended solids has some relation to turbidity - if I remember right, for intakes to drinking water plants (from river, lake etc), suspended solids (mg/l) is ~ 2 x turbidity (NTU) and it's probably similar for treated sewage.

In UK, for river discharge, typical SS limit is 10 mg/l. For sea outfall, usually expressed as % SS removal, but could be up to 100 mg/l.

Cheers..........Codey