Insights

Sewage pollution and Grampian conditions

9/10/2025

Sewage pollution and water quality have increasingly been in the news over the last few years. At first glance this is a dry subject, but it is highly topical. Over the summer an article was published in the Guardian highlighting that sewage is pouring into the rivers inside national parks at twice the rate that is occurring outside the protected areas, and another article was published by the BBC stating that only 10% of water bodies across Hampshire, Sussex and Surrey have a good ecological status under UK regulations. The pollution includes untreated sewage, agricultural run-off, pesticides, plastics and more.

Thousands of new homes, many having the benefit of planning permission, cannot be built because of insufficient sewage treatment facilities, systems and water capacity. Some people consider this issue to be the 'next nutrient neutrality'. Nutrient neutrality has resulted in serious delays in obtaining consent for and building out of, new housing developments because of the requirement not to allow any net increase in nutrient pollution to protect sensitive habitats. The sewage issue is especially relevant now as on 21 July the Government announced that Ofwat, the water regulator, is going to be abolished due to poor performance. Ofwat's functions will be merged with water functions from the Environment Agency, Natural England and the Drinking Water Inspectorate to form a new single, powerful regulator. This is one of the biggest changes to the water sector since privatisation.

It is important to highlight that this is a separate issue from water neutrality which is a very specific issue in a certain part of the country.

Grampian conditions

The Environment Act 2021 mandated the publication of storm overflow and wastewater-treatment data. As a result, councils now have clear information on how often raw sewage escapes from local treatment centres. Consequently, councils have started to impose Grampian conditions in planning permissions. Grampian conditions are negatively worded planning conditions that prevent something from happening until a required action takes place. In this instance, the Grampian conditions are prohibiting the occupation of homes unless upgrades to water-treatment infrastructure are carried out, or capacity is otherwise proven. According to Joey Gardiner, in an article published to the Planning Magazine in July this year, 69 local authorities currently insert such Grampian conditions across areas including East Anglia, the West Midlands, and the Southeast.

The Water Industry Act 1991 empowers local planning authorities to decide planning applications with the understanding that water companies will fulfill their statutory duty to connect new homes with permissions to the networks they oversee and operate. The water companies have a legal obligation to connect a property for which planning permission has been granted. However, even though they are not statutory consultees, water companies are free to advise local planning authorities of the impact of connecting new homes. As a result, local planning authorities can use that advice as a basis for a Grampian condition legally preventing occupation of homes, or even a refusal. 

The recent appeal case of Wealden District Council v Chailey Homes Ltd is informative. The Council successfully defended an appeal that had challenged its refusal to discharge conditions which required provision of a foul drainage scheme. This case showed that councils can use evidence other than that provided by the statutory undertakers, in charge of the sewer networks, to justify the insertion of Grampian conditions. This is permissible even when a water company claims that they have capacity, but alternative evidence suggests otherwise.

Developers, unsurprisingly, are unhappy with the situation. The Home Builders Federation ("HBF") maintains that there is no legal basis for local authorities to block the development of these homes and has written to the housing minister to complain about the problems its members are facing. This could be another major barrier for SMEs and further delay planning decisions from being made. 

More investment needed

Water companies are now spending money to try and fix the ongoing pollution and capacity issues. However, with the introduction of the new housing targets, there is an increased demand, and increased funding will also be needed. The sums involved are already significant. For example, Anglian Water has agreed an investment programme with its regulator in which it plans to spend £280 million upgrading water-treatment centres and £70 million on sewage connections over the five-year regulatory period to 2030. This is only enough to support construction of 175,000 homes over the five-year period and 35,000 per year. However, the target envisaged following the new (increased) standard method for housing within Anglian Water's jurisdiction is just under 60,000 homes per year and just under 300,000 over the five-year regulatory period. More investment will be required to address this issue in the context of the ambitious housing target. 

On 20 July, the Government issued a press release stating that sewage pollution from water companies will be cut in half by 2030. £104 billion is being invested to upgrade crumbling pipes and build new sewage treatment works to reduce sewage pollution into rivers. Over the past year, the Government has introduced a package of measures to slash pollution levels. Bills are now ring-fenced to force companies to invest in upgrades and over £100 million of water fines are being spent on local clean-up projects. This is a positive step by the Government, but it is unlikely that the impact will be felt quickly enough or address the whole issue.

Looking forward 

Interim solutions are coming forward, such as the agreement Oxford County Council entered with the Environment Agency and Thames Water which will see the water company carry out an interim improvement to treatment works, allowing up to 18,000 homes to go ahead and suggestions to allow s106 funds to be used to pay for treatment centre upgrades . However, infrastructure is not being built quickly enough nor is it properly funded. Ultimately, the Government needs to address this issue, to prevent the issue of water supply and sewage being an obstacle for developers every bit as formidable as nutrient neutrality.

This is an issue we all need to be aware of, and it is likely to grow in importance. Howard Kennedy has an experienced planning team able to advise on all aspects related to this topic including Grampian conditions and similar issues. If you would like further information or to discuss this, please contact:

bob.sadler@howardkennedy.com  or danielle.coglin@howardkennedy.com 

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