There are tougher regulations on the other side of the SevernTwm Owen, Local Democracy Reporter and Tristan Cork Chief Reporter
16:00, 03 Jan 2026
Magor Brewery’s waste water treatment plant on the Severn Estuary coast opposite Avonmouth(Image: Google Earth)
A brewery that produces some of the nation’s most popular lagers – including Corona, Stella Artois and Budweiser – has been granted permission to place three giant waste water tanks the height of two double decker buses, on the Severn Estuary coast opposite Avonmouth.
The new tanks will each be 8.66 metres tall are required to meet tough new Welsh Government standards on waste water. The regulations are intended to ensure waste water from commercial uses meets the highest standards of treatment before being discharged into watercourses.
The treatment tanks will be placed on currently undeveloped land and alongside an existing pumping station and tower on the Gwent Levels right on the coastline facing Avonmouth and Portbury. The Magor Brewery, which is based two miles inland near the M4 junction and services, has located its waste water treatment plant on the Levels.
The treatment plant, which is only around 300 metres from the coastline, was undeveloped farmland until its establishment in the 1970s with a second phase of development and expansion in the 2000s, and is within the Magor and Undy Site of Special Scientific Interest (SSSI).
Effluent, foul and most surface water from the brewery, which employs around 500 people, is collected on site within a treatment facility before being carried by a pipeline to the waste water treatment plant where it is processed before being discharged into the Severn, which is a highly protected European Marine Site.
But the Welsh Government recently announced tougher laws on the quality of the water which should be discharged, prompting the Budweiser Group to ask to install the new tanks. Two of the new tanks will be 14.47m in diameter and the third measuring 10.29m, will be finished in a dark green colour to be in keeping with the surrounding landscape and placed on concrete slabs.
Surface water will be discharged into the Mill Reen via a stone filled gabion basket on the reen embankment. Environmental regulator Natural Resources Wales said though its “preference” is to avoid development within the boundary of the highly protected SSSI “it recognises the time pressures faced by the applicant to upgrade their treatment plant to comply with environmental regulations”.
It has required an environmental construction management plan, to avoid or limit harm to the site and the estuary, be included as a condition of the permission.
Natural Resources Wales said it was also “satisfied” with the conclusion of a habitat regulations assessment there would be “no adverse effect on site integrity to the Severn Estuary”.
It did however say the applicants should be aware the site is at risk of flooding and be advised “to install flood proofing measures as part of the development”.