Report No SR3578/1
DISPOSAL OF SEPTIC TANK EFFLUENTS INOct 1994
SUMMARY
Large numbers of properties in isolated rural areas of Scotland and Northern Ireland are reliant on septic tanks for treatment of their sewage. However there are no universally accepted guidelines to deal with the safe disposal of the effluent from these treatment systems in areas where there may be a risk of groundwater contamination, for example in locations with shallow water tables where groundwater is used for potable supplies. The development of such guidelines would be of great benefit to the regulatory water authorities in Scotland and Northern Ireland particularly with respect to the evaluation of planning applications which propose the disposal of septic tank effluents to groundwater.
Consequently, in 1993 WRc was awarded a contract by the Scotland and Northern Ireland Forum for Environmental Research (SNIFFER) to carry out research into the effects of the disposal of septic tank effluents in areas with shallow water tables. The objectives of the research programme were:
The research programme comprised two principal areas: a comprehensive literature study and groundwater quality surveys at a site in Scotland, including the use of bacteriophage tracers. The results of these two areas of study were then used to develop g uidelines which are reported here.
KEY WORDS Septic tanks, effluent disposal, groundwater, bacteriophageCopies of the report are available from FWR, price £12.50, less 20% to FWR Members.