Sustainable Drainage Systems (SuDS) for Hydrocarbons

Completed

Other Power and Storage Technologies(Electricity transmission and distribution)

Applied Research and Development

ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering)

Not Cross-cutting

Project Contact
National Grid Electricity Transmission

Network Innovation Allowance

Ofgem

01 September 2024

31 March 2026

ENA months

£306,000

Power

London

Network Innovation Allowance

Project Contact, National Grid Electricity Transmission

The studies have been split into sections to reflect the scope of works as follows:Phase 1- Discover & Design: Investigate feasibility of Sustainable Drainage Systems (SuDS) to treat hydrocarbons locally to substations (with or without interception integrated into the treatment chain). This desktop study will explore application of different SuDS, as advocated in national guidance documents and NGs Technical Specification, for their effectiveness in the containment and treatment of different types of oil used on NG sites, including mineral oil, synthetic ester and HVO. This will involve literature review of existing case studies. A criterion will be developed for different sites highlighting benefits of SuDS. Guidance will be provided on selection of SuDS most effective to meet site specific characteristics, including identification of sites likely to gain the most benefits by SuDS implementation.Phase 2 - Design & Construction: Site specific SuDS appraisal(s), design, and construction of surface water treatment solution. Operational field trials will be undertaken by NG (the sites will be nominated by NG) to assess the effectiveness of SuDS in a substation environment. A site-specific strategy will be developed to determine the management according to the criterion set out in phase 1. The supplier will provide the site strategy and supervision during the design and construction.Phase 3 Monitoring and Review: Research institution led monitoring programme.After completing Phase 2 & 3, a research institute will lead the monitoring programme of which the scope will be developed following completion of Phase 2 based on NG specifications and site requirements. The success of Phase 3 will be measured by the quantity of pollutants that are removed using SuDS and the biodiversity gain. The reduction in time and cost is also another requirement to measure success of the project. The conclusions of this phase of the work will be combined by NG with the findings from Phases 1 and 2 for review by / presentation to the NIA and NG stakeholders. A final NIA Project report will be compiled by the supplier based on the above study Sections 1, 2 and 3 together with the findings of the operational field trials undertaken by NG. The Scope for the works covers the following services, divided into three phases:Phase 1- Discover and Design Agree the strategic objectives of the research study and design guidelines. This will include a review of which SuDS best meet these objectives and what solutions are to be carried forward to the development of design guidelines. Concurrently, review the typical existing arrangements for surface water drainage and water quality treatment at transmission sites and evaluate the existing pollution loads. This phase will involve a literature review, including existing research, guidance, and case studies. The review will focus on the application of SuDS for the treatment of stormwater runoff from surfaces with the potential high levels of hydrocarbons. This will include a particular focus on the potential for different solutions to remove pollutants, long-term performance, and maintenance requirements. An assessment of the feasibility of the treatment of HVO and synthetic ester using SuDS, this review will be desk based and is dependent on existing research or studies. Criteria will be developed for the selection of sites which could gain the most benefit from implementation of SuDS for treatment of runoff. This considers spatial constraints, discharge location, geology, and hydrology. Guidance outlining the process for selection of SuDS will be developed. This will draw on the findings of the literature review and specifically address the strategic objectives and requirements of NG transmission sites. SuDS design guidelines will be developed, based on available guidance and best practice. Guidance on the typical maintenance requirements for the range of SuDS selected, including the associated indicative costs and timeframes.Phase 2 Design and Construction The guidance developed will be demonstrated on two NG Sites. These sites will be nominated by NG, following the completion of Phase 1. For each of the selected Grid sites, a site-specific SuDS appraisal will be undertaken to determine the most suitable stormwater management strategy for the site in accordance with the strategic objectives set out in Phase 1 of the work. The supplier will provide a site supervision role during construction of the surface water drainage. The programme and fee for Phase 2 will be determined following the selection of the NG sites.Phase 3 Monitoring and Review A research-institution led monitoring programme will be implemented. The scope of this programme is to be developed following the completion of Phase 2 based on the NG specific criteria set out in Phase 1 and specific requirements of the site identified in Phase 2. The programme and fee for Phase 3 will be determined following the completion of Phase 2.Key findings across all deliverables will be presented in a workshop with NGET staff. A discussion on implications of the project, opportunities to focus on will be presented and motivated by the results of the study. This project will help us in addressing the optimal whole life cycle criteria with the following objectives:Develop understanding on the possibility of implementation of SuDS.Understanding of specific assets degradation and risk characteristics.Design and construct SuDS in accordance with design principles on NG sites.Understand the possibility of biodiversity enhancement as compared to BAU.Ensure as a business we are adequately addressing environmental impacts of our proposed activities whilst enabling the transition to Net Zero.

National Grid (NG) manages many oil containing assets and oil storage is susceptible to leakages. The use of alternative insulating fluids in transformers has been studied by NG and synthetic esters are now considered where enhanced fire safety and a more environmentally friendly solution is required. NG currently uses Bund Water Control Units (BWCU) and oil separators to capture oil, both of which require maintenance and are less effective to ester and emulsified mixtures. However, the existing oil capturing techniques used for mineral oil are not 100% effective with newer alternatives. This project looks at alternative oil capturing and bioremediation techniques with or without existing oil interceptors, with respect to the potential environmental implications based on typical pollution scenarios at NG sites.

09/04/25