The Building Regulations, Part H – SI 561 (2010)

H1 -- Drainage System

1. A building shall be provided with a drainage system necessary for the hygienic, adequate disposal of foul wastewater from the building.

2. A building shall be provided with a drainage system necessary for the adequate disposal of surface water from the building.

3. No part of a drainage system conveying foul wastewater shall be connected to a sewer reserved for surface water and no part of a drainage system conveying surface water shall be connected to a sewer reserved for foul wastewater.

H2 -- Wastewater Treatment Systems

1. Wastewater treatment systems shall be designed, sited and constructed so that –

they are not prejudicial to anyone’s health,
they do not cause a risk to public health or the environment,
they prevent unauthorised access but allow adequate means of access for emptying and maintenance,
they will function to a sufficient standard for the protection of health in the event of a system failure,
they have adequate capacity,
they are impermeable to liquids and
they are adequately ventilated.

2. Information on wastewater treatment systems and any continuing maintenance required to avoid risk to health and the environment shall be provided to the owner.

H3 -- Definitions

‘combined drain’ – a single private drain used for the drainage of two or more separate premises as defined by Section 10 of the Local Government (Sanitary Services) Act 1948 (No. 3)

‘drain’ – relating to a building, any pipe forming part of the drainage system of the building either –

wholly underground or
a continuation in the direction of flow of part of a drainage system that has been underground, including a ‘combined drain’

‘drainage system’ – relating to a building, the system of pipes and drains used for drainage of the building including all other fittings, appliances, and equipment used, but excluding subsoil water drains

‘domestic wastewater’ – water discharged from kitchens, laundry rooms, lavatories, bathrooms, toilets, and similar facilities (soil water and wastewater)

‘foul wastewater’ – any wastewater comprising wastewater and/or industrial wastewater

‘industrial wastewater’/’trade effluent’ – wastewater discharge resulting from any industrial/commercial activity

‘sewer’ – meaning as that of the Local Government (Sanitary Services) Acts 1878-1964

‘surface water’ – water from precipitation that has not seeped into the ground, discharged to the drain or sewer system directly from the ground or exterior building surfaces

‘soil water’ – water containing excreted matter – human or animal

‘wastewater’ – used water (not soil water or trade effluent)

What are the regulations on drainage and wastewater disposal?