NUTRIENT NEUTRALITY EXPERTS
The UK's Leading Nutrient Neutrality Specialists
We specialise in nutrient neutrality assessments and mitigation strategies that help developers achieve planning approval while protecting the environment. With over 35 years of combined civil and environmental engineering experience, our team has completed more than 750 nutrient neutrality assessments — with over 90% achieving nutrient neutrality on-site through innovative, engineering-led solutions.
TECHNICAL UNDERSTANDING
Why Phosphorus & Nitrogen Matter
Phosphorus: Catch all term for all forms of phosphorus (inc phosphates). Usually originate from wastewater discharges via treatment plants or septic systems.
Nitrogen: Catch all term for all forms of nitrogen (inc nitrate, nitrite and ammonia). Primarily enter the environment through surface runoff and agricultural drainage.
Both nutrients fuel algal blooms, which deplete oxygen and disrupt aquatic ecosystems. Our expert civil engineers calculate nutrient budgets by analysing foul and surface water drainage, soil conditions, and treatment performance, ensuring compliance with nutrient neutrality regulations.
UNDERSTANDING THE CHALLENGE
What Is Nutrient Neutrality?
Nutrient neutrality means ensuring that new development does not increase nutrient pollution — especially phosphates (phosphorus) and nitrates (nitrogen) — entering sensitive rivers, lakes, and coastal habitats.
In simple terms: Nutrient neutrality ensures that any additional nutrient loading from a new development is balanced or offset, so there is no net increase in pollutants like phosphorus or nitrogen reaching protected ecosystems.
Excess nutrients can lead to eutrophication, harming biodiversity and water quality. As a result, Natural England and DEFRA require developers to demonstrate nutrient neutrality before planning consent is granted.
PROVEN TRACK RECORD
Our Expertise in Nutrient Neutrality Assessments
We combine engineering design and environmental science to deliver precise, cost-effective nutrient assessments. Our engineers are qualified to optimise foul water drainage and wastewater treatment plant design, surface water runoff control and attenuation, soil infiltration and site hydrology, and nutrient offsetting strategies and credit calculations.
Assessment Experience
Over 750 successful assessments across the UK
90% on-site neutrality achievement rate
Trusted by Natural England and LPAs
National Rivers Consortium partnership
Described as "an asset" by Natural England
Technical Capabilities
Phosphorus, phosphates, nitrates, and nitrogen mitigation
Foul water drainage optimisation
Surface water runoff control
Soil infiltration and site hydrology
Nutrient offsetting and credit calculations
OUR SERVICES
Comprehensive Nutrient Mitigation Services
Our holistic approach means we deliver the lowest achievable nutrient budget while ensuring full compliance with Natural England's nutrient neutrality guidance.
Nutrient Neutrality Assessments
Complete assessments for planning applications, using Natural England's latest calculators and methodologies to demonstrate compliance.
Phosphate & Nitrate Mitigation
Engineering-led design of mitigation measures to reduce phosphorus and nitrogen loads through optimized treatment and drainage.
Drainage & Treatment Solutions
Design of drainage systems and wastewater treatment solutions that minimize nutrient discharge while meeting development needs.
Package Treatment Plants
Specification and design of PTPs with enhanced nutrient removal capabilities for sensitive catchments.
Septic Tank Upgrades
STU designs for existing developments, working with the National Rivers Consortium to deliver catchment-wide improvements.
Effluent Testing & Compliance
Comprehensive testing protocols and ongoing compliance monitoring to ensure long-term nutrient neutrality.
Why Choose Enviren
35+ Years Experience
Combined civil and environmental drainage design expertise
National Recognition
Expertise in SuDS, nutrient neutrality, and off-mains systems
Full Compliance
Designs satisfy NPPF, PPG, and CIRIA guidance
End-to-End Service
Complete coordination delivering cost-effective solutions
750+ Projects
Proven track record across all development scales
94% Success Rate
Near-perfect approval rate at first submission
Frequently Asked
Questions
What is nutrient neutrality in planning?
Nutrient neutrality is a requirement ensuring that new development does not increase nitrogen, phosphorus, or phosphate pollution in rivers, lakes, or protected habitats. Developers must prove that their projects achieve no net increase in nutrient loading, often through engineering mitigation or off-site credits.
Why are phosphates and nitrates important for nutrient neutrality?
Phosphates and nitrates are key contributors to water pollution. They cause eutrophication, which degrades ecosystems. Controlling phosphorus and nitrogen through sustainable drainage and treatment systems is essential for meeting nutrient neutrality standards.
How do you calculate nutrient neutrality?
A nutrient neutrality assessment involves calculating baseline nutrient levels, estimating the nutrient output from proposed development, and identifying measures to offset or reduce excess nutrients — ensuring no net increase of nitrogen or phosphorus.
What areas in the UK are affected by nutrient neutrality?
Nutrient neutrality applies across various catchments in England, including the Solent, Tees, Wye, Stour, and Avon. Natural England regularly updates affected zones based on ecological sensitivity and nutrient loading levels.
How can Enviren help achieve nutrient neutrality?
We offer engineering-led nutrient neutrality strategies, optimising foul and surface drainage to minimise phosphorus and nitrogen loads. Our tailored solutions often achieve on-site neutrality, saving developers time and money on nutrient credit schemes.
What is the difference between phosphates and phosphorus?
Phosphorus is a chemical element (P), while phosphates are its compound form found in wastewater and fertilisers. Both are measured to determine nutrient pollution and play a crucial role in phosphate mitigation strategies for nutrient neutrality compliance.
What are nitrogen and nitrate mitigation strategies?
Nitrogen and nitrate mitigation focuses on reducing nutrient discharge through measures such as wetlands, buffer zones, enhanced wastewater treatment, and soil infiltration design, ensuring minimal impact on protected habitats.
Do you guarantee reductions in nutrient budgets?
Yes. We guarantee the lowest achievable on-site nutrient budget. If we cannot reduce a scheme's nutrient budget by at least 10% compared with a baseline approach, we do not quote—ensuring clients only invest where we add measurable value.
How do nutrient credits and off-site mitigation work?
If on-site neutrality is not feasible, legally secured off-site mitigation or nutrient credits can balance residual nitrogen and phosphorus. Credits must be demonstrably additional, enforceable and aligned with the affected catchment's rules.