Sewage Treatment Plant Upgrade in River Parrett Catchment, Somerset
The Problem: Outdated Sewage System Causing Phosphate Pollution
A homeowner in Somerset’s River Parrett catchment was facing a significant wastewater challenge. Their 5-bedroom property, formerly operated as a bed and breakfast, relied on an oversized 12-person VSM sewage treatment plant installed over 30 years ago.
The deteriorating system was no longer fit for purpose and was contributing to phosphate pollution in the ecologically sensitive River Parrett catchment – a critical environmental concern for the region.
The Challenge: Difficult Site Access and Adverse Weather Conditions
This sewage treatment plant replacement project presented several logistical obstacles:
Site Access Limitations: Restricted garden access required ground protection boards to prevent damage to the property during installation.
Weather Complications: Installation took place during an exceptionally wet week, significantly complicating excavation and construction work.
Site Preparation: Before work could commence, the WCI team carefully removed 100 patio slabs and raised flower beds to access the installation area.
The WCI Solution: Zero-Cost Phosphate Mitigation Upgrade
Through the WCI phosphate mitigation scheme, we installed a compliant sewage treatment plant upgrade at zero cost to the homeowner.
Assessment and Planning
Following an initial site assessment and eligibility verification, our project engineer specified a modern GRAF 7-person one2clean package treatment plant as the optimal replacement—properly sized for the property’s current needs.
Professional Installation Process
Our experienced team managed every aspect of the installation:
- Careful removal and storage of garden features
- Strategic use of ground protection systems
- Safe decommissioning and backfilling of the old VSM plant
- Professional commissioning by a British Water Accredited and GRAF Trained WCI Service Engineer
All work was completed to the highest industry standards, despite challenging weather conditions.
Results: Environmental Impact and Customer Satisfaction
Environmental Benefits
The new GRAF one2clean sewage treatment system delivers substantial environmental improvements:
- Phosphate reduction: 1.01kg TP/year removed from the River Parrett catchment
- Nutrient neutrality: Direct contribution to regional water quality goals
- Long-term compliance: Modern, efficient system meeting current environmental standards
Property Benefits
The homeowner received a right-sized, aesthetically pleasing, and highly efficient wastewater solution that:
- Meets current household needs (properly sized for 7 people vs. oversized 12-person system)
- Provides reliable, compliant sewage treatment
- Requires minimal maintenance
- Came at zero cost through our phosphate offset scheme
Customer Satisfaction
The project was completed to the homeowner’s complete satisfaction, with their review highlighting WCI’s exceptional organization, professionalism, and commitment to client service.
Conclusion: Individual Action for Collective Environmental Protection
This successful upgrade through the WCI No Nonsense Nutrient Neutrality™ Scheme demonstrates how individual property improvements contribute to broader environmental protection goals in phosphate-sensitive catchments.









