Substation expansion projects, Scotland - Pollution Prevention Plan

Key environmental concerns

1. Peat stabilisation: Cementitious material had to be mixed with peat to create a stable base for a concrete plinth.

2. Water contamination: The interaction of water and cement risked elevating pH levels to above 12, posing significant environmental risks too local water receptors.

3. Additional pollutants: These included suspended solids, COSHH substances, hydrocarbons, and sewage from welfare facilities.

The project did not meet the requirements of the Controlled Activities (Water Environment) Regulations and as such was guided by General Binding Rules, setting a no-visual-discoloration standard for water and an acceptable pH threshold of 6-9.

Solution: Tailored risk management and pollution control

As with any PPP, it’s only as valuable as the information upon which it is based. Understanding the risk landscape enabled the creation of a robust PPP. Collaborative discussions with Luddon Construction's management ensured that the plan was both environmentally sound and budget-friendly.Using the principles outlined in Naturally Compliant’s ‘six steps to successful surface water management’, we identified the receptors (see What is a receptor) and implemented the following measures.

Key measures:

1. Isolation and drainage: The construction area was isolated from surface water flow by extending the existing substation drainage system.

2. Addressing pollutants: We sized settlement ponds based on CIRIA guidelines (C532, C648, and C753) to capture suspended solids. Sizing ponds is critical when creating a PPP to ensure the expected particles settle, preventing pollution.

3. pH level control: A dedicated bunding area was created for peat stabilisation, and any water breaching acceptable pH levels underwent CO2 treatment to neutralise the pH before being discharged into the settlement lagoon.

Outcome: A prompt approval and on-schedule start

The PPP was completed in one week and received developer approval the following week, allowing Luddon Construction to stay on schedule. No revisions were necessary.

Recommendations for future projects:

Early consultation: Engaging an environmental consultant during the tender process helps to identify and budget for unforeseen environmental measures. For instance, the CO2 treatment system in this project represented an additional cost that could have been budgeted for earlier.

By executing a robust plan that balanced regulatory requirements with practical constraints, Naturally Compliant facilitated a smooth, on-time project commencement for Luddon Construction.

If you’d like to know more about ho our team can support your next project, please dont hesitate to get in touch.