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Sewer Extension/Requisition

External to Site

Application & Assessment


  • You will be requested to submit a design deposit prior to detailed design commencing.

Approval & Payment

  • Once the detailed design is complete, you may be required to pay any shortfall in costs.
  • You will be required to meet any shortfall in costs before construction commences.

Construction & Completion

  • We will construct the sewer within 6 months of receipt of payment and bond surety being in place.
  • Our extension will include connection to your site.
  • You will be responsible for any further individual sewer connections to the public sewer using our new Connections Portal.

Requisition of a Public Sewer

Guidance Notes

Article 154 - Water and Sewerage Services (Northern Ireland) Order 2006 (as amended Water and Sewerage Services Act (Northern Ireland) 2016)

Please note that Water Loading Units are required when the requisition is to serve Commercial or Industrial properties / developments.

Under Article 154 of the Water and Sewerage Services (Northern Ireland) Order 2006 (as amended Water and Sewerage Services Act (Northern Ireland) 2016) (‘the 2006 Order’) it is the duty of NI Water to provide a public sewer for domestic purposes if required to do so by certain person(s) (the requisitioner).

Requisitioners are encouraged to obtain the participation of as many neighbours as possible, who could benefit from the new sewer, if provided.

NI Water will complete an economic appraisal study based on positive responses; on occasion this leads to an interested few having to accept the full burden of the cost of the scheme.

The requisitioner may be asked to make a contribution towards the cost of providing the requisitioned sewer. The requisitioner will be responsible for the cost of the first 20m of the requisitioned sewer and may be asked to make a contribution to the remaining requisitioned sewer based on the number of units served. This is known as the ‘Requisition Charge’. NI Water will contribute towards the cost of constructing the requisitioned sewer, this is known as the Reasonable Cost Allowance (RCA).

If you have been notified in response to a Pre-development Enquiry (PDE) that there are sewers available within 20m of the curtilage of the developer’s land and you require a connection you can apply for a sewer connection (SC-A163).

Requisitioning a sewer means that NI Water is responsible for the design and construction, including the acquisition of appropriate easements or rights over the land in which it will be laid. After construction NI Water will be responsible for maintaining the sewers as part of the public sewerage system. 

Construction of the private drain should be arranged by respective individual property owners. 

The requisitioning procedure takes time to process and may be costly. The requisitioner should be aware of the lead-in times and make submissions and requests in ample time. Where the sewer requisition is required for a development where it is proposed that the sewers be considered for adoption under Article 161, it should be noted that it may not be possible to release the Article 161 until the requisitioned sewer is designed. Subject to technical and land issues this may take on average eight to nine months.

When is Requisitioning Applicable?

Sewers can only be requisitioned for the purposes of servicing:

  • existing buildings or land where it is proposed to erect buildings and
  • buildings or properties from which it is proposed to remove:

a) the contents of WC’s;

b) water used for domestic cooking;

c) water used for domestic washing; and

d) surface water from the buildings and land occupied with and appurtenant to them.

However, subject to separate negotiations outside the provisions of Articles 154 and 157 of the 2006 Order, NI Water may be willing to:

  • provide additional capacity within requisitioned sewers for commercial and industrial effluents; and/or
  • provide additional capacity for highway drainage in surface water sewers requisitioned for domestic purposes.
  • However, we cannot provide public sewers solely for this purpose

What cannot be Requisitioned?

Public sewers may not be requisitioned for the following:

  • the drainage of land on which it is not intended to erect buildings;
  • commercial effluents, including those from laundry businesses and businesses preparing food for consumption off the premises;
  • highway drainage; or
  • land drainage such as ditches, watercourses and subsoil drainage.

Who can Requisition Sewers?

A sewer may be requisitioned by the owner or occupier of any existing or proposed premises. The cost, design and routing will be based on our preferred technical option and best economic solution. The detailed design route selection and programme will of course take into account the point of connection, expected flows and timing of connections as are reasonably required by the applicant. Route selection will also be by agreement under Article 156 (3) of the 2006 Order. Where agreement cannot be reached with the landowner either party may refer the matter to the Authority (NIAUR).

It is also possible for the owners and occupiers of existing premises to requisition a sewer. Terms and conditions are similar to those for developers. 

In order to assess the requisition completion of the Water Loading Units table will also be required for Commercial properties /developments only.

Reasonable Cost Allowance

NI Water when making an economic assessment of the requisition will consider what reasonable cost allowance will be considered to offset the cost of the requisition. This will be detailed in our initial decision letter. Further details can be located on NI Water document “Scheme of Charges” which can be viewed on

Requisition Procedures

The requisitioning of a public sewer consists of four key stages:

Stage 1 Initial assessment and preliminary feasibility estimate

The preliminary feasibility estimate will cover the following costs:

  • land and compensation (including easements where applicable);
  • site investigation (including environmental constraints) ;
  •  civil engineering works;
  •  mechanical and electrical works (only when a pumping station is involved);
  • design; and
  • contract management and administration.

Developer will be notified in writing of the estimated contribution (requisition charge) required if applicable .The request for a preliminary estimate does not commit the applicants to requisition a public sewer, however the requisitioner must undertake to pay reasonable costs of providing the sewer if they want to proceed.

Stage 2 Detailed design, including land negotiations

  • detailed design will only be progressed when terms and conditions set out in the initial decision letter have been met.

Stage 3 Completion of the Requisitioned Sewer

  • Following completion of the detailed design the Requisitioner will be notified in writing of our final decision including any financial conditions if applicable
  • Once the terms and conditions are met the scheme will progress to construction

Additional Charges

As well as the associated cost of the requisitioned sewer there will be additional infrastructure and connection charges. Details can be located on NI water document “Scheme of Charges” which can be viewed on

Timescales and Programme

The time taken to complete the requisition depends entirely on the complexity of the scheme. Under the 2006 Order, the requisitioned public sewer must be available for use within six months of:

  • the day on which the financial conditions are met and or
  • the day on which the point of connection has been agreed whichever is later or
  • the day on which the places of connection are agreed or determined, subject to the financial conditions being met.

The date by which the requisitioned sewer is available for use may be extended by agreement.

In certain circumstances, it may not be possible to complete the requisitioned public sewer within the six-month period. This may be because:

  • major construction works are required and it is not physically possible to complete the requisitioned public sewer within the six month period;
  • works are required in land in the ownership of undertakings protected by the Order (eg Crown Estates, Network Rail etc) or a third party and agreement is required with them prior to our entry upon their land;
  • land, not in the ownership of the requisitioner, needs to be purchased for elements such as pumping stations;
  • where there is a dispute the period for delivery of the requisitioned sewer may be extended by the Authority.

Financial Conditions of Compliance

The requisitioner must undertake to pay reasonable costs of providing the sewer.

 This will also include cost of the first 20m of the requisitioned sewer. If insufficient units are constructed prior to construction of the sewer the requisitioner may be required to provide reasonable security in the form of a legal Agreement and guarantee bond or cash deposit. NI Water administration and legal costs are invoiced separately, payable at completion of the requisition process, and are not included in the requisition costs quoted herein. 

The reasonable cost to provide the sewer includes the cost of administration, design, construction, supervision, lands costs, compensation costs, all necessary new public sewers and pumping stations, etc. The cost estimate detailed in our decision letter at Stage 3 above will be the final cost to the applicant. 

Payment will be made in a single payment, paid as the requisition Agreement is signed, to cover all our costs.

Securities / Bonds

Under the 2006 Order, undertakers are entitled to ask for security before installing the new sewer. This is usually provided in the form of a cash bond. However, a bond or insurance policy provided by a guarantor is equally acceptable.

It is important to note that there may be additional costs for the requisitioner in the administration of a bond or insurance policy. 

Public Authorities are exempt by Statute from a requirement for security

Connection to Requisitioned Sewer

Applicants are responsible for connecting private drains between their buildings and the lateral drain, (a lateral drain is the length of pipework between the demarcation chamber, or the boundary of the property it serves, and the sewer), if one is provided via the requisition. NI Water cannot carry out such works as part of the requisition.

Requisitioners should employ their own competent contractor to lay connecting drains to the sewer or lateral drain. They should obtain all necessary approvals and Building Control consents and must serve a sewer connection notice on us under Article 163 of the 2006 Order. (Application form SC-A163)

Connection work in public carriageways must be carried out at the point of connection, to the satisfaction of NI Water.

Should you require any further information or assistance please contact Developer Services:

Developer Services - Servicing Team

Northern Ireland Water

Ballykeel Office

188 Larne Road



Co Antrim BT42 3HA

Tel: 03458 770 003

Email: developerservices[AT]niwater[DOT]com

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