Environmental Assessment & Spill Mapping Delivers Significant Cost Savings

Effective pollution prevention is not always about installing more equipment — it is about understanding risk.

A large manufacturing site in the West Midlands, supplying Jaguar Land Rover, identified a pollution issue affecting a nearby watercourse. Following initial review, the local Environment Agency advised that surface water runoff should be routed through an oil separator system.

The proposed solution came with an estimated capital cost of over £300,000.

If you are being advised to install containment or treatment systems, it is critical to ensure the solution matches the actual risk — we can provide an independent technical review.

The Challenge

Before proceeding with the installation, Sandfield Penstock Solutions were asked to review the proposed design.

Initial observations raised concerns:

• The site had minimal hydrocarbon risk
• The proposed solution appeared disproportionate to the likely source of pollution
• There was limited understanding of the site’s drainage behaviour

Engineering Approach

Rather than proceeding directly to design, we carried out a full site spill and firewater runoff risk assessment, including:

• Drainage mapping and flow path analysis
• Inspection of key infrastructure
• Identification of potential contamination sources
• Assessment of worst-case spill scenarios

Understanding how water and contaminants move through your site is fundamental — we can map and assess your drainage system to identify real risks.

Findings

The root cause of the pollution was not hydrocarbon contamination.

Instead, our engineers identified:

• A non-operational pump chamber
• Long-term lack of maintenance
• Soluble oil escaping via overflow into the surface water system

This issue had gone undetected due to limited visibility of the drainage network.

Outcome

Based on the findings:

• The proposed oil separator system was deemed unnecessary
• The pollution source was clearly identified and addressed
• The client avoided a £300,000 capital project
• A more effective, targeted solution was implemented

In this case, installing the originally proposed system would not have prevented the pollution incident.

Key Insight

Most pollution risks are misunderstood — not unmanaged.

Without a clear understanding of:

• Drainage pathways
• System condition
• Actual contamination sources

…it is easy to invest in solutions that do not address the real problem.

Modern Approach: Spill Mapping & Risk-Based Design

Following projects like this, we developed our Spill Mapping approach — enabling clients to:

• Visualise worst-case spill scenarios
• Identify true containment requirements
• Make informed, evidence-based investment decisions

This removes guesswork and ensures compliance with CIRIA C736 guidance.

If you want to understand the real pollution risk on your site — rather than rely on assumptions — request a spill mapping assessment.

Conclusion

This project demonstrates that effective pollution prevention is not about installing more infrastructure — it is about installing the right solution.

In many cases, the greatest value comes from:

• Identifying the true source of risk
• Understanding system behaviour
• Applying targeted engineering solutions

Discuss Your Requirements

Whether you are:

• Reviewing a proposed solution
• Responding to regulatory pressure
• Looking to achieve CIRIA C736 compliance

We can support with:

• Independent technical assessments
• Spill and firewater modelling
• System design and optimisation

Request technical input
Speak to our team