Phosphorous is a nutrient that occurs naturally in low levels and is necessary for the healthy functioning of rivers. It is released slowly at low levels from natural sources, from natural bankside erosion for example.

However, in high levels it is the most harmful nutrient in freshwater and can lead to eutrophication. Eutrophication happens when an excess of nutrients causes a dense growth of plant life and subsequent death of animal life due to lack of oxygen.

The main sources of phosphorous are from:

• agriculture (found in fertilisers and runoff from manure)
• sewage (from homes and other developments that generate wastewater containing sewage, food waste and cleaning products).

The Joint Nature Conservation Committee has found new evidence that warmer and drier weather, predicted as a result of climate change, could reduce river flows during the summer and therefore increase phosphate concentrations.

The new targets are also based on new evidence about the damaging effects of phosphates to water ecosystems and species.

Currently, over 60% of waterbodies in Wales fail against the tighter targets. Welsh local planning authorities are being asked to take more action to avoid further deterioration of the environment.

Any proposals for development within SAC river catchments (particularly those that will generate increased volume or concentration of wastewater) must now prove that the design will not contribute to increased phosphate levels.

The River Dee is designated as a SAC, and the majority of Wrexham County Borough is located within its catchment. The river is currently failing against NRW’s targets.

Until we have received further guidance and are able to measure and mitigate the impact on phosphate levels, we are unable to determine some planning applications in these SAC areas.

This is not unique to Wrexham - this has affected other Welsh local planning authorities and many construction projects across Wales have been put on hold. Whilst we are working hard to reach a solution, this may unfortunately take some time.

We have written to Welsh Government outlining our concerns about the impact on development and have made clear that we want to find a solution as quickly as possible.

We are also:

• producing guidance to help developers understand what is required
• creating a phosphate calculator for developers to calculate the level of phosphates their development will generate, together with calculations to mitigate and offset phosphate levels

We recognise that this situation will be frustrating for developers. We want to work with you to find solutions that improve the condition of our rivers that are feasible and can be implemented quickly and successfully.

We want to engage with a wide range of people including those representing homebuilders, employers, the farming community, residents and environmental groups to discuss these issues.

Types of development that may be affected include (this list is not exhaustive and is subject to review):

• New residential units including homes, gypsy and traveller sites/pitches.
• Tourism attractions and commercial developments where overnight accommodation is provided.
• Agricultural development, including prior notifications (developments that don’t require planning permission, but where we need to check that it is allowed) including additional barns and slurry stores likely to lead to increased herds.
• Prior notifications for change of use of office to homes and agricultural buildings to homes.
• Operations which generate phosphate such as fisheries and car washing facilities.

Currently we are unable to process some applications of this type. Our position will be updated once we have received further guidance and are able to measure and mitigate the impact on phosphate levels.

We are still able to determine some applications in the county borough, including:

• Any development that does not increase the volume or concentration of wastewater, including extensions that do not increase occupancy or the volume or concentration of wastewater
• Any development which improves existing water quality discharges by reducing phosphates in wastewater, or by decreasing the volume of wastewater produced (for example, by improvements to existing wastewater treatment infrastructure)
• Private sewage treatment systems discharging domestic wastewater to ground that:
  • are built to the relevant British Standard (BS 6297:2007+A1:2008)
  • have a maximum daily discharge rate of less than 2 cubic metres (m3)
  • have a drainage field which is located more than 40 metres from any surface water feature such as a river, stream, ditch or drain
  • have a drainage field which is located more than 50m from a SAC boundary
  • has the discharge to ground at least 200m from any other discharge to ground and the density of discharges to ground are no greater than 1 for every 4ha (or 25 per km2), this is necessary so that there is no significant in combination effect

If you have not yet submitted an application you may wish to wait for further progress on solutions.

If you still wish to proceed, or have already submitted an application, please provide us with as much information as possible regarding the foul drainage proposals for your site. This is especially important if you are in a non-mains sewer area. This will help us when considering the impact of your development on phosphate levels.

You could withdraw your application and wait for further progress on solutions or speak to your planning officer to agree an extension to your application.

You could also exercise your right of appeal if no decision has been made after eight weeks from when your application was registered/validated. However the Planning Inspectorate will also consider the impacts of the development on phosphate levels.

Welsh Government: Planning and Environment Decisions Wales (external link)

We also advise you to keep an eye on your application progress on our system and to sign up for updates.

Our initial understanding of the guidance meant that we screened in any application for a domestic extension that created the potential for increased occupancy in a dwelling.

The application of this rule has several implications, including both:

• quality of life for occupancy levels that do not change
• socio-economic implications including the retention of families in affected catchments

Therefore the efficacy of correlating extensions with an increase in wastewater levels is not satisfactorily reliable.

NRW have not issued new guidance on this, but have instead provided further explanation on the screening of applications for domestic extensions. They have stated that it would be unreasonable to assume that a domestic extension (meaning an extension to a dwelling house comprising a single household, which will remain a single household) would result in a corresponding increase in foul water volume from the property. This is because the occupancy of that property is outside the control of the planning system.

As a result of this explanation from NRW, a potential change in the number of inhabitants of the property should not justify the triggering of likely significant effects on a SAC.

We have taken the decision to apply this interpretation to applications for domestic extensions in the SAC catchments in Wrexham, as a practical and common-sense approach.

Please note that this rule does not apply to applications for an annexe.

It is not normally considered environmentally acceptable to install a private sewage treatment plant in areas where there are main sewers. This is because there is greater risk of failure, which could lead to pollution.

Welsh Government planning guidance states that, where possible, new development foul drainage should be discharged into a public sewer.

Natural Resources Wales: private sewage treatment in an area with a public sewer (external link)

If you can demonstrate that connection to a public sewer is not feasible (due to cost or practicability), then a private treatment plant or non-mains foul sewage disposal could be considered.

You must have an environmental permit, or register an exemption with NRW, to operate a private drainage system.

NRW will not normally grant a discharge permit for a private sewage treatment system where it is reasonable to connect to the public foul sewer.

When there is a change from existing commercial (or other similar) use to residential use it is assumed that this will result in more waste-water being produced. It is therefore also assumed that there will be more nutrient discharges to waste-water treatment plants.

These plants have a set capacity, and when reached there is no easy way to create more space. This creates greater risk of overloading which could increase nutrient discharges into watercourses.

This type of change of use must have a habitats regulations assessment and mitigation measures considered.

GOV.UK: habitats regulations assessments (external link)

Certain new agricultural developments have the potential to contribute towards the amount of phosphorus entering the designated site. These developments are those where both of the following applies; the development:

• involves the storage, management and spreading of organic material
• is within the catchment of a river SAC

It is likely that these developments will be affected and you will need to provide mitigating measures.

There are nutrient management, land, manure, and habitats management measures you can put in place to reduce the amount of phosphate entering rivers from diffuse sources. You can also make immediate changes, for example erecting fencing along riverbanks to prevent livestock entering the rivers.

We would like to explore catchment management ideas with the farming community. Please contact our Planning Department to discuss this.

Healthy rivers support social, economic, and environmental resilience and the capacity to adapt to change.

We understand concerns about the environmental quality of these rivers. We want to find solutions that enhance biodiverse natural environments and promote healthy functioning ecosystems.

We want to work with environmental and river groups in finding solutions and would welcome your involvement. Please contact our Planning Department to discuss this.