To ask the Minister for Infrastructure pursuant to AQW 16423/17-22, (i) to detail (a) the number of recorded incidents of spills from the network; and, (b) their locations; (ii) the number of recorded incidents of flooding in properties as a result of sewage backing up; (iii) to define the meaning of ‘receiving environment’; (iv) to detail the number of unsatisfactory intermittent discharges; (v) what planning approvals and funding have been obtained thus far for improvement works; (vi) for an update on network modelling in regards to the Larne area; (vii) what engagement has been undertaken thus far with the Northern Ireland Environment Agency regarding required work; and (viii) what notice has been given to the public in regards to these issues.

NI Water has advised me of the following:

NI Water’s urban drainage model developed for the Larne catchment provides information on predicted spills/discharges from network assets into the environment. The table below outlines the predicted network spills and defines the receiving environment.

NI Water has no properties on the external, or internal, flooding DG5 register for the Larne catchment. It has also advised that where flooding has occurred the cause would have been sewer blockages i.e. flooding other causes and not capacity related.

The receiving environment is referenced in the table above, provided in response to question (i).

NI Water is currently aware of 29 Unsatisfactory Intermittent Discharges (UIDs). This information is based on evidence derived from the urban drainage model, pollution incidents and operational staff, within the Larne network. NI Water has provided spill assessment data to the Northern Ireland Environment Agency (NIEA) for its consideration and to enable a formal ‘Statement of Need’ for Larne to be generated.

NI Water has advised that it can progress options to provide solutions, land requirements and planning when it receives the Statement of Need from NIEA. The implementation of any capital improvements in Larne will be subject to prioritisation and the availability of adequate funding. NI Water’s PC21 Business Plan includes provision for network sewerage improvements within the Blackcave network.

NI Water is currently awaiting the Utility Regulator’s PC21 Final Determination which will include decisions on NI Water’s PC21 Business Plan proposals amounting to approximately £2 billion for the period 2021 to 2027. Funding of the PC21 Business Plan, if agreed by the Utility Regulator and NI Water, is reliant on the allocation of adequate funding by the NI Executive. NI Water has advised me that it will take multiple Price Control investment timeframes to address the wastewater system capacity issues. This presents a challenge for the Executive as to how economic development can be supported while the necessary investment is delivered. If insufficient funding is provided, a prioritisation exercise will need to be undertaken, and agreed, with my Department and NI Water’s key stakeholders (the UR, NIEA, the Drinking Water Inspectorate and the Consumer Council Northern Ireland). This could lead to significant impacts upon the wastewater upgrade programme.

NI Water is currently progressing a Drainage Area Study (DAS) of the Larne catchment (encompassing the Blackcave network). This study, which involves the creation of a detailed hydraulic model to replicate the sewerage network, is at an advanced stage with an anticipated completion date of June 2021. Substantial survey work has been undertaken in the Larne catchment to inform the DAS process (including flow survey, ancillary surveys and CCTV investigations).

The modelling appraisal has identified network capacity issues affecting the catchment. NI Water has, using the DAS process, developed a suite of outline solutions to address both pollution from unsatisfactory overflows and to reduce the risk of out of sewer flooding. The scale of the solutions generated by the DAS (based on precautionary environmental principle) represent a significant capital investment. Therefore it is likely that NI Water will seek to achieve more sustainable catchment outcomes through a parallel Integrated Environmental Modelling (IEM) study.

NI Water provided spill assessment data on 22nd April 2021 to the Northern Ireland Environment Agency (NIEA) for its consideration and to enable a formal ‘Statement of Need’ for Larne to be generated. Please refer to previous answer (iv).

NI Water has highlighted wastewater capacity issues, both in relation to Larne and other areas across Northern Ireland, for several years. It’s PC21 Business Plan sets out investment requirements to begin addressing capacity issues over the PC21 Price Control period (2021 to 2027) and for future 6 year Price Controls (PC27 and PC33). The Utility Regulator also issued the PC21 Draft Determination for Public Consultation on the 30 September 2020 and presented the proposals as to how NI Water will begin to address a lack of capacity in its sewerage networks and wastewater treatment works in the PC21 period.

NI Water has made several presentations to Mid and East Antrim Borough Council during 2019/20 and 2020/21. Its staff have also met, on numerous occasions, with Councillors, Council Planners, MEA Chief Executive, MLAs and an MP.

Wastewater capacity information is available on NI Water’s website: Wastewater Capacity (niwater.com).