Urban WastewaterTreatment Directive
Obligations and milestones

Tertiary treatment — nitrogen and phosphorus

Nutrient removal linked to plant size and the sensitivity of receiving waters.

Back to the obligation overview
Topic context

What is changing and why preparation matters

Tertiary treatment follows biological treatment and reduces nitrogen or phosphorus in discharged water.

Operators need to connect receiving-water designation, design load, technology, permitting and operational monitoring.

Timeline

Obligations and their practical meaning

Each block has a permanent link. Always verify the exact scope against the agglomeration and plant profile and the final Czech implementation.

Preparation and planning

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

Preparation: 2027–2028#sensitive-areas

Tertiary treatment — nitrogen and phosphorus

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

What this means in practice

Confirm sensitivity to nitrogen and phosphorus, the decisive load, achievable performance and the investment steps required.

  • Sensitive-area designation, treatment project and nutrient-monitoring results.
  • Implementation period: 2027–2028.
  • Keep the evidence traceable and ready for reporting.

Scope and evidence

Who it applies to: Agglomerations from 10,000 p.e. discharging into sensitive areas.

Evidence: Sensitive-area designation, treatment project and nutrient-monitoring results.

Why this step matters

Reducing nutrient loads limits eutrophication and protects sensitive surface waters.

Legal context: Directive requirements for tertiary treatment.

Broader requirements

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

National milestone: 2033#tertiary-20

Tertiary treatment — nitrogen and phosphorus

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

What this means in practice

Confirm sensitivity to nitrogen and phosphorus, the decisive load, achievable performance and the investment steps required.

  • Sensitive-area designation, treatment project and nutrient-monitoring results.
  • Implementation period: 2032–2033.
  • Keep the evidence traceable and ready for reporting.

Scope and evidence

Who it applies to: Agglomerations from 10,000 p.e. discharging into sensitive areas.

Evidence: Sensitive-area designation, treatment project and nutrient-monitoring results.

Why this step matters

Reducing nutrient loads limits eutrophication and protects sensitive surface waters.

Legal context: Directive requirements for tertiary treatment.

Stricter targets

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

National milestone: 2036#tertiary-40

Tertiary treatment — nitrogen and phosphorus

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

What this means in practice

Confirm sensitivity to nitrogen and phosphorus, the decisive load, achievable performance and the investment steps required.

  • Sensitive-area designation, treatment project and nutrient-monitoring results.
  • Implementation period: 2036.
  • Keep the evidence traceable and ready for reporting.

Scope and evidence

Who it applies to: Agglomerations from 10,000 p.e. discharging into sensitive areas.

Evidence: Sensitive-area designation, treatment project and nutrient-monitoring results.

Why this step matters

Reducing nutrient loads limits eutrophication and protects sensitive surface waters.

Legal context: Directive requirements for tertiary treatment.

Advanced implementation

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

National milestone: 2039#tertiary-60

Tertiary treatment — nitrogen and phosphorus

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

What this means in practice

Confirm sensitivity to nitrogen and phosphorus, the decisive load, achievable performance and the investment steps required.

  • Sensitive-area designation, treatment project and nutrient-monitoring results.
  • Implementation period: 2039.
  • Keep the evidence traceable and ready for reporting.

Scope and evidence

Who it applies to: Agglomerations from 10,000 p.e. discharging into sensitive areas.

Evidence: Sensitive-area designation, treatment project and nutrient-monitoring results.

Why this step matters

Reducing nutrient loads limits eutrophication and protects sensitive surface waters.

Legal context: Directive requirements for tertiary treatment.

Long-term objectives

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

National milestone: 2045#tertiary-100

Tertiary treatment — nitrogen and phosphorus

Prepare and operate nutrient removal where receiving waters are sensitive to nitrogen or phosphorus.

What this means in practice

Confirm sensitivity to nitrogen and phosphorus, the decisive load, achievable performance and the investment steps required.

  • Sensitive-area designation, treatment project and nutrient-monitoring results.
  • Implementation period: 2045.
  • Keep the evidence traceable and ready for reporting.

Scope and evidence

Who it applies to: Agglomerations from 10,000 p.e. discharging into sensitive areas.

Evidence: Sensitive-area designation, treatment project and nutrient-monitoring results.

Why this step matters

Reducing nutrient loads limits eutrophication and protects sensitive surface waters.

Legal context: Directive requirements for tertiary treatment.

Related content

Interpretations and important terms

Find more detail on legal concepts and the Czech approach in the related interpretations and glossary.

Related interpretations and tools

Glossary terms