Report No SR6002

FORECASTING THE DEPOSITION AND BIOLOGICAL EFFECTS
OF EXCESS ORGANIC CARBON FROM SEWAGE
DISCHARGES A REVIEW OF THE LITERATURE

SR6002

JUNE 1994

SUMMARY

EXECUTIVE REVIEW

The literature was reviewed on several topics relating to the deposition and biological effects of organic carbon. Varying amounts of literature were found on the several relevant topics.

Very little information was found regarding the nature of discharged effluent in the UK More information may be obtainable from various sources but overall there is little data in a useful form.

There is a reasonable amount of literature on the physical processes affecting the fate of solids discharged from sewage outfalls in coastal areas. Several numerical models exist which predict the fate of suspended solids in a marine environment. A few of these have been developed to relate changes in sediments and bottom-dwelling organisms to the characteristics of waste water discharge and the receiving environment. The models which encompass the sediment and benthos apply more directly to deeper outfalls in southern California and may not be very applicable in the UK.

The rates of primary production and sedimentation of associated products are reasonably well documented for areas all over the world. As primary production and sedimentation rates are very variable, it is impossible to make generalisations.

There is much literature regarding the effects of excess organic carbon on the sediment and benthos. The great majority of this literature is descriptive and of a qualitative nature. Very little information exists which is of a quantitative nature.

The literature review has identified several areas where further work is required in order to be able to produce a model which will forecast the deposition and biological effects of excess organic carbon from sewage discharges. Recommendations for further research are made.

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