If your business is in an area where no main sewers are available then you may need to use a cesspool or wastewater treatment system such as a package treatment plant or septic tank.
A cesspool is a watertight tank with no outlet. In Scotland, building regulations do not allow you to use cesspools. You will need to empty your cesspool regularly to prevent it overflowing. Fit your cesspool with an alarm that lets you know when it is nearly full. This is an emergency back up and it should not be the only method you use to check the tank.
Septic tanks provide some basic sewage treatment. You must make sure that the effluent from your septic tank is further treated, for example by a filter or reed bed, before you dispose of it to a watercourse. You may be able to dispose of it by soaking it away to ground using a herringbone system for example, if you have sufficient land and the drainage conditions are favourable.
Package treatment plants produce a higher quality effluent which you may be able to discharge to the water environment.
You will need to carry out a percolation test if you want to use a drainage field to dispose of the effluent from your septic tank or package treatment plant. This will confirm whether the area is suitable for a soakaway and will determine the size of the drainage area you need. Pollution Prevention Guideline (PPG) 04 contains more information on percolation tests.
If you plan to install a new system or alter your existing system of sewage disposal you should contact your environmental regulator at an early stage to discuss your plans.
Authorisations and licences for your septic tank or package sewage treatment plant
You must have an authorisation, such as a licence, permit or consent, from your environmental regulator before you discharge any sewage, effluent or contaminated run-off to the water environment. This includes discharges to groundwater via soakaway. You must comply with any conditions in your authorisation.
Your environmental regulator will not normally give you authorisation to discharge to the water environment if it is possible for you to connect to the public sewer.
You may need an environmental permit (England and Wales) or a waste management licence (Northern Ireland and Scotland) from your environmental regulator if you treat effluent from another business’ site.
If you need to construct a new outfall structure for your discharge:
- In England and Wales you may need land drainage consent from the Environment Agency.
- In Northern Ireland you will need prior consent from the Department of Agriculture and Rural Development (DARD) Rivers Agency.
- In Scotland your discharge authorisation will cover the construction.
Maintenance of septic tanks and package treatment plants.
Follow the manufacturers operating instructions to make sure that the wastewater treatment system operates effectively.
You must use a registered waste carrier to empty your cesspool or to remove sludge from your septic tank or treatment plant. You need to check that your waste carriers is registered with their environmental regulator.
You should make sure that clean surface water, for example from roofs and parking areas, does not enter your treatment system. The extra water will reduce the effective capacity of the system and may flush solids out.
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