PPS 21 Sustainable Development in the Countryside·Page 47·5.95
Refusal of planning permission for unsatisfactory non-mains sewerage
Planning permission will be refused where on-site sewage treatment arrangements are unsatisfactory or where Consent to Discharge is unlikely due to pollution risks. The Environment Agency may identify areas where pollution risk warrants no further development using non-mains sewerage, to be highlighted in development plans.
Planning permission will be refused for development relying on non-mains sewerage where the physical arrangements proposed for on-site sewage treatment are unsatisfactory or in cases where 'Consent to Discharge' under the Water Order is unlikely to be forthcoming due to pollution risks. The Northern Ireland Environment Agency may identify certain areas where a pollution risk exists sufficient to warrant no further development relying on non-mains sewerage arrangements. In appropriate circumstances these will be highlighted in the relevant development plan for the area.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/PPS 21 - Sustainable Development in the Countryside.pdf