Discharges from Bellozanne sewage treatment works (FOI)

​Request

Would the Department for Infrastructure publish a table showing the number, time and duration of discharges into St Aubin Bay from the Bellozanne waste facility over each of the last five years?

This table should also show the quantity and type of waste that was discharged.

Response

The discharges from Bellozanne sewage treatment works are of a continuous nature and it is therefore not possible to give the number, time and duration of discharges.

The discharges vary depending on the incoming flow, and there is generally a pattern with two daily peak flows, one in the morning and one in the evening. The tables below show the daily average flows for each month from 2013 to 2017.

2013-2017-Sewage Flows

The second data column in the table represents the average daily volume of flow that is fully treated during that month. In cases where the flow is high due to heavy rain the sewage works cannot always treat all of the flow. The third data column shows the volume of flow which has only received partial treatment.

Partial treatment consists of four stages:

• screening for solids

• fat, oil, grease and grit removal

• primary treatment

• UV treatment