Scottish Government

2. Legal framework

2.1 Water Service etc. (Scotland) Act 2005

2.1.1 The regulation of odour emissions from WWTW previously relied upon the Statutory Nuisance controls in Part III of the Environmental Protection Act 1990 that are enforced by local authorities. These controls required that operators of WWTW did not cause a Statutory Nuisance due to emission of odours.

2.1.2 However, the Water Services etc (Scotland) Act 2005 provided new powers in sections 25 to 26 (attached as Annex 3) to allow Scottish Ministers to make an order containing a code of practice (referred to as the Sewerage Code) for the purpose of assessing, controlling and minimising Sewerage Nuisance. Sewerage Nuisance is defined in section 25 of the Water Services etc (Scotland) Act 2005 as:-

'smells and discharges, insects or any other thing emanating from or present at any part of the public sewerage system so as to be prejudicial to health (that is to say, injurious, or likely to cause injury to health) or a nuisance'.

2.1.3 The aim of the Sewerage Code is to detail what standards are required for Scottish Water to demonstrate that they are complying with the Code and also to set out guidance as to the best practicable means of assessing, controlling and minimising Sewerage Nuisance. The Code applies to Scottish Water and any other person who is acting on Scottish Water's behalf or under it's authority.

2.1.4 Section 26 of the WSSA requires that each local authority must monitor compliance with the CoP and where complaints of Sewerage Nuisance are made to it, to investigate the complaint. If the local authority is satisfied that Scottish Water is not complying with (or is not likely to comply with) the CoP, the authority must serve an Enforcement Notice on Scottish Water. The Enforcement Notice may require the execution of such steps necessary for ensuring compliance with the CoP and must specify the date by which the requirements of the notice are to be met.

2.1.5 The person on whom an Enforcement Notice is served has the right of appeal to the sheriff within 21 days of the service of the notice and such an appeal suspends the effect of the notice until the appeal is determined or withdrawn.

2.1.6 A person who fails to comply with the requirements of an Enforcement Notice without reasonable excuse is guilty of an offence and liable to a fine on summary conviction not exceeding £40,000. Further, when a notice has been contravened a local authority may take proceedings in the sheriff court to secure compliance with the conditions of the notice.

2.1.7 Once the Sewerage Code has been adopted, local authorities will not be able to use the provisions of sections 79 to 81 of the Environmental Protection Act 1990 to deal with Sewerage Nuisance due to odours arising from WWTW. However, this does not prevent any private individual or group taking private action under section 82 of the Environmental Protection Act 1990 to seek an order from the Sheriff to abate the nuisance and prohibit the recurrence of the nuisance or local authorities dealing with other nuisances from WWTW or the sewerage network.

2.2 Sewerage Nuisance (Code of Practice)(Scotland) Order 2006

2.2.1 The first Sewerage Code is contained in the Schedule to the Sewerage Nuisance (Code of Practice)(Scotland) Order 2006 that came into force on 22 April 2006 relating to odour from WWTW. The Code represents guidance as to the best practicable means for assessing, controlling and minimising odour nuisance and also the detailed requirements against which compliance with sections 25 and 26 of the Act can be measured.

2.3 Compliance with the CoP

2.3.1 Section 25(3) of the WSSA provides that the CoP may provide guidance as to the best practicable means of assessing controlling and minimising sewerage nuisance and also the circumstances is which Scottish Water (or any other person to whom the CoP applies) can be regarded as complying with the Code. The measures that represent compliance are clearly defined in paragraph 4 of the CoP as follows:_

Code of Practice Requirement - Paragraph 4

The circumstances in which Scottish Water or any other person to whom this Code of Practice applies is to be to regarded as complying with it are that:-

2.3.2 Paragraph 4 of the CoP requires:-

1. All WWTW directly meeting the requirements of paragraphs 6 to 9 of the CoP (which are preparing and implementing an OMP, maintaining a documented complaints procedure, implementing baseline measures and training staff)
2. Where an odour nuisance exists after compliance with these requirements, an OIP must be prepared in accordance with paragraph 10 of the CoP
3. Meeting the primary requirement to prevent odour nuisance beyond the WWTW boundary as outlined in paragraph 3(2) by implementing the control measures that represent bpm based upon the assessment carried out in the OIP (taking account the requirements of paragraphs 11 and 12 in respect of enhanced controls)
4. All odour control equipment must meet the odour reduction performance required by paragraph 13 except where the abatement equipment already exists on 22 April 2006 where it can be accepted until the end of its reasonable operational life provided that emissions from the equipment do not result in odour nuisance beyond the site boundary.

2.4 Best Practicable Means (bpm)

2.4.1 The CoP at paragraphs 6 to 9 establishes certain 'baseline' standards that apply to all works and at paragraph 15 provides an upgrading schedule for compliance. These standards are largely management-based controls and there may be occasions when even having applied these controls, an odour nuisance exists. In these cases the CoP provides the framework in paragraphs 10 to 13 to establish additional works that may be necessary which meet the 'best practicable means' (bpm) to assess, control and minimise nuisance. The term best practicable means (bpm) is defined in section 25 of the Water Services etc (Scotland) Act 2005 as:-

''best practicable means' is to be construed by reference to the following provisions-

1. "practicable" means reasonably practicable having regard to local conditions and circumstances, the current state of technical knowledge and to the financial implications; and
2. "means" includes the design, installation, maintenance and manner and periods of operation of plant and machinery, and the design, construction and maintenance of buildings and other structures;

2.4.2 The key issue when determining bpm usually relates to the interpretation of 'practicable'. The definition includes cost consideration but clearly cost is not necessarily the decisive factor. The procedures and controls outlined in this guidance establish a basis against which the term 'best practicable means' (bpm) for control and minimisation of Sewerage Nuisance due to odour from WWTW can be compared.

2.5 WWTW Regulated under other Statutory Controls

2.5.1 The CoP is intended to apply to WWTW where the Water Services etc (Scotland) Act 2005 is the main or only source of regulation for odour emissions. For example, a relatively small number of WWTW fall under the Integrated Pollution Prevention and Control ( IPPC) regime and are regulated by the Scottish Environment Protection Agency ( SEPA) under the Pollution Prevention and Control ( PPC) Regulations.

2.5.2 The PPC Regulations require that certain operations for the treatment of waste are subject to the IPPC regime under SEPA regulation. The definition of installations subject to these controls is included in the Pollution Prevention and Control (Scotland) Regulations 2000 as amended and outlined below:-

(a) The disposal of hazardous waste (other than by incineration or landfill) in a facility with a capacity of more than 10 tonnes per day.
(b) The disposal of waste oils (other than by incineration or landfill) in a facility with a capacity of more than 10 tonnes per day.
(c) Disposal of non-hazardous waste in a facility with a capacity of more than 50 tonnes per day by -
(i) biological treatment or
(ii) physico-chemical treatment.

2.5.3 In addition, under the provisions of Part II of the Environmental Protection Act 1990, a number of works may be required to hold a Waste Management Licence. Further guidance on dealing with odours from such works is included in paragraph 3.1.3.