Discharge to controlled waters

The Environment Agency has a duty to protect the quality of controlled waters. In spite of the offences under the Water Resources Act, it is possible, under some circumstances, with a consent, to discharge contaminated water directly to the environment. To obtain a consent, you will need to apply to the agency (see Control of Pollution (Applications, Appeals and Registers) Regulations 1996 on page 21 of EEF Register of Environmental Legislation).

The agency inspectors will then look at the body of water which will receive your site’s discharge and assess the likely harm to water quality which will result. If a consent is granted, a series of conditions will be attached.

The quality of the water will be strictly controlled. Typical discharge parameters will be:

Effluent characteristics

Key characteristics (parameters) are:

These characteristics are important in terms of environmental impacts. For example, high levels of particulate matter in surface water can have a detrimental effect on the photosynthetic activity in the aquatic environment. Also, effluent with a high BOD can stimulate microbial growth which removes oxygen from the water and reduces the amount of oxygen that is available to sustain life in the aquatic environment.

Other parameters such as temperature and pH will also be specified and tightly regulated. Some contaminants will not be allowed at all, for example, free oil or ‘Red Listed’ chemicals.

UK Red List

The UK's Red List (introduced in 1989 and due to be revised in the longer term by the new Water Framework Directive), is used for prioritising regulatory control in UK. It is a list of 23 substances that are considered to be the most dangerous if released into water, e.g. heavy metals, PCBs and pesticides.

The list is based on persistent, toxic and bioaccumulative characteristics of the substances.

• Persistence – the ability of a substance (and its properties) to continue to exist in the environment, i.e. it is unaffected by outside forces; and
• Bioaccumulative – the progressive accumulation of a substance at increasingly higher levels in the foodchain.

If the site in question handles metals, limits may be put on certain metal ions in the discharge, (even if the release of dissolved metal ions is only a remote possibility).

The Environment Agency will require the holder of the consent to provide a safe and accessible sampling point where its technicians will make regular visits and take samples. Reports will be sent to the consent holder.

The agency will charge a fee for the privilege of making a consented discharge. Any excursions above limits could result in loss of the consent and, possibly, prosecution.

Soakaways

When dealing with water run off there is no such thing as a ‘dead end’. An apparently blind-ending run of pipework will either be a sump, which will need periodic emptying, or a ‘soakaway’.

A soakaway is a means of allowing water runoff to seep gradually to the groundwater. Since groundwater is part of the controlled waters defined in the Water Resources Act (see Water Resources Act 1991 Part III on page 19 of EEF Register of Environmental Legislation), a consent is also required for a soakaway.

Nuisance

Those bodies of water not classified as controlled waters under the Water Resources Act 1991 are still within the reach of statute law.

Any body of water which is not controlled under the Water Resources Act can, if problems occur, be dealt with under statutory nuisance provisions (see EPA 1990 Part III in EEF Register of Environmental Legislation and emissions to air).

Outside controlled waters, any pond, pool, ditch, gutter or watercourse that is so foul or in such a state to be prejudicial to health or a nuisance will be treated as a statutory nuisance.