Discharges to Sewer

• Sewerage (Scotland) Act 1968

Discharge to the public sewer in Scotland requires consent under the Sewerage (Scotland) Act 1968.

Section 1 of the Sewerage (Scotland) Act 1968 and Section 6 of the Water (Scotland) Act 1980 impose obligations on Scottish Water to provide sewerage and water services, respectively, "where it is practicable to do so at reasonable cost".

• Water Industry Act 1991

Discharge to the public sewer in England and Wales requires consent under the Water Industry Act (WIA) 1991. Part III of the Act governs the supply of sewage services and provides for the discharge of trade effluent into the public sewer.

Under Section 106 of the Act the owner or occupier of any premises is entitled to have his drains or sewer connected to the public sewage system. He is not however entitled to discharge the following directly or indirectly into the public sewer unless specifically consented to do so by the local sewerage undertaker (Scottish Water or equivalent):

a) any liquid from a factory, other than domestic sewage or surface or storm water, or any liquid from a manufacturing process, or;

b) any liquid of other matter the discharge of which into the public sewers is prohibited by or under and enactment.

• Water (Scotland) Act 1980
• Water Act 1989
• Urban Waste Water Treatment (Scotland) Regulations 1994

These regulations implement in Scotland the Urban Waste Water Treatment Directive (91/271/EEC).They extend duties to Local Authorities and the Secretary of State under Part II of the Sewerage Scotland Act 1968 to control industrial waste water.

• Urban Waste Water Treatment (England and Wales) (Amendment) Regulations 2003

These regulations implement the Urban Waste Water Treatment Directive (91/271/EEC) in England and Wales. They extend the duties of sewerage undertaker, Director general of Water Services and Secretary of State under chapter III, Part IV of the Water Industry Act to control industrial waste water.

• Water Industry Act 1999

Although this Act is largely concerned with water charging it also created the office of the Water Industry Commissioner for England and Wales, with the general function of overseeing the interests of the customers of the water authorities and acting as the authorities' customer services and economic regulator.

• The Water Industry (Scotland) Act 2002

Introduced the Water Industry Commissioner for Scotland and established Scottish Water to replace the North, South and East of Scotland Water Authorities.

• Water Environment and Water Services (Scotland) Act 2003

This Act is the enabling legislation for the EU Water Framework Directive (2000/60/EC). It is largely concerned with the development of River Basin Management Plans and enables new controls on water abstraction, engineering works, point source pollution and diffuse pollution from urban areas and farms. The Directive repeals older EU Water Directives and incorporates the remaining existing water directives on Bathing Water, Nitrates and Urban Waste Water Treatment.

Part 2 of the Act makes changes to the system for funding new connections to the water and sewerage infrastructure by amending the Sewerage (Scotland) Act 1968 and the Water (Scotland) Act 1980.

General guidance on compliance with regulations can be found at on the Envirowise website.

To discharge to the public sewer requires a trade effluent discharge consent from the appropriate company, usually the water company or sewage undertaker. These companies are required by law to accept effluent where it conforms to accepted standards. A charge is levied appropriate to the level of service provided. The company may grant consents unconditionally or subject to certain conditions which the sewerage undertaker thinks fit to impose with respect to:

• The sewer or sewers into which the trade effluent may be discharged;
• The nature and composition of the trade effluent which may be discharged;
• The maximum quantity of trade effluent which may be discharged on any one day, either generally or into a particular sewer; and
• The highest rate at which trade effluent may be discharged either generally or into a particular sewer.

For information on discharges to sea, surface waters or groundwater - see Discharges to Controlled Waters.

Trade effluent discharge consents will usually state the following conditions:

• the maximum permitted daily flow (m3/day);
• the maximum hourly flow (m3/hour);
• the permitted pH range, typically pH 5-9;
• the maximum biochemical oxygen demand (BOD) or chemical oxygen demand (COD) value, expressed in milligrams of oxygen requirement per litre (mg/l);
• the maximum concentration of suspended solids (SS) in mg/l.

They may also include stated limits on particular substances such as oil, copper, zinc or organic chemicals such as phenols which could affect treatment facilities or affect the final composition of discharge from sewage works to the environment.

Applications must be made in writing to the local water company or sewerage undertaker.

The relevant water company is required to make a decision on an application for consent within 3 months of receiving the application.

The consent is likely to detail the allowable discharge rate(s) and volume(s), and the periods during which discharges can be made.

The consent is likely to include discharge standards for suspended solids; biochemical oxygen demand (BOD); pH; temperature; oil, fat and grease content; and specific chemicals such as metals, sulphates, nitrates, fluorides, cyanide and organic chemicals.

In addition, the consent will list prohibited substances such as calcium carbide, carbon disulphide, free oil, flammable or explosive materials including petroleum spirit and organo-halogen compounds.

The monitoring/sampling requirements are case specific, but are likely to cover the following:

• Facilities for taking samples;
• Meters for measuring or recording the volume and rate of discharges and apparatus for determining the nature, composition and temperature of the discharges;
• Recording of sampling and monitoring data (i.e. maintaining a log book).

The consent may require the operator to forward the monitoring results for certain substances to the water company at specified time intervals.

In addition, the water company may visit the site to undertake inspections, measurements, or tests to ensure compliance, or take away and analyse samples of water or effluent or of any land or article.

Inform the local water company or sewerage undertaker (e.g. Scottish Water) immediately.

Discharge of any trade effluent, from any trade premises, without the consent or other authorisation is an offence (Section 118(5)).

Contravention of a trade effluent condition is an offence and the occupier of the premises shall be liable to a fine not exceeding £20,000 and/or imprisonment not exceeding 3 months, on a summary conviction. An unlimited fine or prison sentence of up to two years may be imposed if convicted on indictment.

Defra are undertaking consultation on a new Waste Water National Policy Statement. Consultation closes 22nd Februrary 2011.

The Environment Agency has indicated that it intends to introduce a new regime for England and Wales to 'modernise' discharge consents. After consultation it is intended to introduce a regime based on Operator Pollution Risk Appraisal (OPRA) and more self monitoring. The new regime dates are yet to be finalised.