SuDS

SuDs Management at Glenconway

Windfarm

SuDs

Introduction to Gael Force Renewables

SuDs

• Gael Force Renewables Ltd was formed in 2011 by McLaughlin & Harvey Ltd and William & Henry Alexander (Civil Engineering) Ltd to target onshore Wind Farm opportunities in GB & ROI.

SuDs

Gael Force Renewables – What We Do:

• 150 years of Civil Engineering Experience

• Gael Force offer full Design and Build Services

• Early client and designer involvement so that innovative, safe, buildable solutions are developed. • At Gael Force we implement lessons learnt to ensure our teams constantly progress, develop and

refine skills, methodologies and work sequences

• Full time on site Environmental Professionals

SuDs

Project - Balmurrie Fell Wind Farm, Stranraer, South West Scotland. (7 x 1.3 MW Siemens WTG)

SuDs

Project – Glenconway Windfarm, Limavady, Northern Ireland (20 x 2.3MW WTG)

SuDS

Design to Construction

SuDS

Settlement Ponds

SuDS

Silt Fencing

SuDS

Clean water cut off drains

SuDS

Swales & check dams

SuDS

Breakouts

SuDS

Settlement Areas

SuDS

Monitoring Effectiveness

• Water Quality testing (internal & external) • External inspections by Designers • Internal weekly inspections by

Environmental Representative • SEARS (Safety Environmental Awareness

Reporting Scheme). Positive and Negative issues raised by everyone on site.

SuDS

SuDS

Water Quality Testing

• External water quality testing was carried out every two weeks at 5 locations for Phase 1 and 8 locations for Phase 1 & 2

• Testing covered 21 chemical parameters and biological (macro invertebrate) monitoring

• Internal samples took place daily for phase 1 and weekly for phase 2. Parameters included turbidity, dissolved oxygen, pH, temp & EC.

SuDS

Environmental Awareness

• Water Quality results are displayed on site

• Correlation between turbidity and rainfall is also presented on graphs.

SuDS

Toolbox Talks

• Every Tuesday morning

• Covers key issues such as waste, energy, water pollution

• All site staff shared the responsibility

SuDS

Environmental Awareness

SuDS

Environmental Coaching

Environmental Sessions to date:-

SuDS (McCloys) Peat Stability / Peat Slides (BLP) Archaeology (Gahan & Long) Flora and Fauna (Blackstaff)

SuDS

SuDS

Conclusion

• SuDS design must account for inclement weather conditions

• SuDS design must be site specific • SuDS features must be installed prior to works

starting • Very beneficial to have an on site environmental

representative • Water Quality monitoring is important during

construction – even visual inspection of water courses

• Maintenance of SuDs Features is critical

Richard Collins BSc MSc AIEMA

Construction-Phase Temporary SuDS: A75 Case Study

Construction Context

• 3.67km carriageway realignment and upgrade: include earthworks, drainage and culverts, utility works, surfacing & underpass construction

• Existing drainage mitigation inadequate

• Filter drains & 4 balancing ponds with reed beds

Key Environmental Aim

‘Protecting the Pow Water tributaries during construction’

Challenges & Uncertainties

• Geology & soils

Earthworks intensive

EIA stated ‘potentially increased sedimentation’

True nature of soils

Fine Clays

• Spatial constraints

Limited opportunity for temporary SuDS locations

• Temporal Constraints

Not scheduled in programme of works

Resources to complete with immediate effect

Costs

Usual Suspects

Exposed soils: ensuring capping/seeding is completed ASAP

Stockpiles: limiting, stabilising

Washing & washout facilities

Haul roads: wheel wash operative (spatial constraints)

Dewatering: sumps, releasing at suitable times

Inclement weather: be prepared

Water Management Strategy Liaise with local SEPA representative

Alum sulphate required: minimal dosing policy

Tiered, impermeable treatment zones

Maintenance plan: Daily checks

pH (6-8) & turbidity (<10ntu) testing

Controlled release

Tangible Results

Permanent Pond Installation

• Isolated pond • Limited opportunity for

treatment • Use of existing vegetation

• Lined sediment forebay • Aquatic bench in

permanent pool; ecology, amenity & safety

Native Species Planting Pond Edge Mix

Yellow Flag Iris

Water Avens

Benefits of bio-retention and enhanced biodiversity

Meadowsweet

Learning Points Detailed pre-construction review of EIA

Robust planning, management & maintenance required

Micro-managed retention & release

Maximise use of sub-catchments in design

Thank you