Trade effluent If your business is discharging non-household sewage (trade effluent) to the public sewer, you will need to obtain consent. From large food and drink manufacturing sites to car washes and laundrettes, all these businesses need trade effluent consent. Mobile businesses such as car valeting services and cleaning operations (stonework and fire damage) need consents along with businesses who are carrying out cleaning operations including vehicle washing. Consent is required because trade effluent discharges from business and industrial premises can have harmful effects including damage to sewers, sewage treatment processes and watercourses. Short term discharges of less than six months duration such as chemical cleaning of chilled and hot water heating systems need a temporary consent.