Many properties in the Dee catchment are not connected to the public sewer network and are instead serviced by private sewerage systems such as septic tanks, package sewage treatment plants and cesspits. These can cause pollution to watercourses if they are not maintained properly, as any leakage can increase phosphate levels in rivers. Phosphate increases the growth of plants such as algae, which ‘choke’ the river surface and reduce available oxygen for fish and other aquatic animals. The result can be fish kills and a reduction in aquatic biodiversity.
Recent modelling indicates that 7% of phosphorous discharged into the Dee catchment is from sources including septic tanks and urban run-off. While this may be a small percentage compared with rural land use (48%), sewage treatment works (34%) and storm overflows (11%), it is one area which the average homeowner can directly impact when looking for ways to improve the health of our rivers.
Discounts when you ‘do it for the Dee’
Most septic tanks are ‘living’ and can only perform as well as they are treated. In a healthy septic tank, naturally occurring bacteria breakdown the waste and if input guidance is followed any soakaway will not impact local watercourses. This means a clean river catchment for you to enjoy! You can help us to look after the River Dee by following this advice:
- Have your system emptied by a registered waste carrier regularly to ensure it doesn’t cause pollution.
- Maintain your system regularly, getting any faults or problems fixed immediately.
We’ve partnered with two local companies to encourage more people to regularly service and maintain their septic tank by offering a discount.
PD Construction and Plant Ltd
A family run business providing a range of sewerage services covering parts of the Dee catchment including Bala, Corwen, Cerrigydrudion, Glyndyfrdwy, Llangollen, Llanarmon Dyffryn Ceiriog, Glynceiriog Valley, Chirk, Wrexham, Llandegla and Treuddyn.
Book to get your domestic sewage treatment system emptied and get £15 off when you mention Welsh Dee Trust.
Envirocare North West
An experienced company providing a range of sewerage services covering parts of the Dee catchment including Chester, Tattenhall, Farndon, Malpas, Bangor-on-Dee and Wrexham.
Book to get your domestic sewage treatment system emptied and get 10% off with the code IT SHOULDN’T BE IN THE DEE.
Septic tank
Empty annually, although small single occupancy households can do it every other year
Cesspit
Empty twice a year, more if it’s a larger household
Package plant
Service annually and empty at least every two years
See & Smell
Looked after properly, your system will keep working happily for years. But how can you tell if something is going wrong? Here are a few tell-tale signs that might mean your sewage treatment system isn’t working as it should be:
- Drains are slow to clear or toilets are backing up. These are the most obvious signs that your system isn’t working. It could be that pipes are blocked, the tank is full of solids or the drainage field is clogged up.
- The ground above the drainage field or soakaway is spongy or has lots of lush vegetation and grass growing. This is also a sign that the drainage field might be clogged up.
- Dark, smelly liquid at the end of the discharge pipe. A clear liquid is normal, anything dark, smelly or containing solids means there’s a problem with your system.
Taking the time to check, maintain and empty your system not only saves you money in the long run, but also helps prevent sewage leaking into our natural environment. Skipping regular maintenance means you are risking costly repairs, or even having to replace it altogether. If you are not sure about how well your system is working, then ask your emptying contractor for advice – they may be able to carry out a system health check.
Additional guidance
- Register your septic tank or small sewage (package) treatment plant (Natural Resources Wales)
- Running and maintaining a septic tank or small sewage plant (Natural Resources Wales)
- Guidance for Pollution Prevention: Treatment and disposal of wastewater where there is no connection to the public foul sewer
- Waste carriers, brokers and dealers public register (Natural Resources Wales)
- Small sewage discharges in England: the general binding rules (Environment Agency)
- Register of Waste Carriers, Brokers and Dealers (Environment Agency)
- Code of Practice: Flows and Loads – Sizing Criteria, Treatment Capacity for Sewage Treatment Systems (British Water)
- A guide for users of packaged wastewater treatment plants (British Water)