EFFECTS OF THE RECHARGE OF SEWAGE EFFLUENTS UPON THE QUALITY OF CHALK GROUNDWATER

The results show that, with a slight reservation about trace organics, effluent recharge to the chalk is not only an acceptable method of disposal on water quality grounds but could perhaps be adopted more widely as a resource conservation measure. Provision of sewage treatment appears to be immaterial as regards the groundwater quality some hundreds of m from the recharge site except in so far as nitrogen removal is prevented if conventional biological treatment is provided. Obviously effluent recharge could not be used in areas of major fissuring of the chalk. In the Southern Water Authority such areas are thought to be confined to parts of north-west Kent and the areas adjacent to and beneath the tertiary outcrop in Southern Hampshire and Sussex.