Have your say on South West Water upgrade request for St Mabyn
The Environment Agency wants to hear your views as South West Water seeks permission to process more sewage waste in St Mabyn, Cornwall.
Inside of a rotating biological contactor
A consultation has opened as South West Water seeks permission to process more sewage waste in St Mabyn,Cornwall.
South West Water has applied for an environmental permit. This will allow the water company to upgrade the capacity of its Wadebridge Road wastewater treatment works. Extra volume of 12m3 per day – the same capacity as a large van - is requested so that the site can process sewage from the Chapelfields housing development. This waste is currently being taken away by tanker for treatment elsewhere.
The Environment Agency is ‘minded to’ accept this permit request as the initial application was consulted on between 20 August and 17 September 2025. A second consultation period is now open and, to reflect high public interest, will be run for an extended period and close at 11.59pm on 26 January 2026. During this consultation you can comment on the draft decision document, which outlines our thinking and views on comments from the previous consultation, and the draft permit.
This upgrade is purely to accommodate domestic sewage from the Chapelfields estate. It will only accept domestic sewage, not surface water or storm overflow. It will also not have the capacity to accept flows from any future significant housing developments. SWW will be responsible for ensuring that it directs future potential housing developers to alternative options for sewage treatment.
Treated effluent, in line with the limits in the permit, will continue to be discharged into a tributary of the River Allen. The treated effluent would be subject to various limits set out by the permit to ensure that it does not pollute the stream and cause harm to the wildlife living within it.
If there aren’t any technical reasons to refuse the permit application, we are bound by the Regulator’s Code to issue the permit. This is a government policy to ensure regulators do not obstruct economic development.
Anyone wishing to comment on the application, can do so by using our online consultation portal, Citizen Space, email pscpublicresponse@environment-agency.gov.uk or write to Environment Agency Permitting and Support Centre, Land Team, Quadrant 2, 99 Parkway Avenue, Sheffield, S9 4WF.
If you need help accessing this consultation in another format, please email DCISEnquiries@environment-agency.gov.uk or call 03708 506 506. We may charge for copying costs.
Please use the application reference number, EPR/NP3924LT/A001. The consultation closes at 11.59pm on 26 January 2026.