Many municipal and industrial facilities across North America operate aging lagoon systems that struggle to meet today’s effluent requirements for BOD, TSS, ammonia, and phosphorus. Lagoons are simple and robust, but their treatment performance is limited by seasonal temperature swings, poor mixing, low oxygen transfer, and the absence of controlled biological zones.
Upgrading a lagoon to the BIOWORKS® extended aeration process allows owners to retain their existing basin infrastructure while converting it into a high-performance activated sludge system. This approach minimizes civil construction, reduces capital cost, and delivers a modern treatment process with long-term reliability.
Why Lagoons Benefit from a BIOWORKS® Upgrade
Traditional lagoons rely on long detention times and natural processes. The BIOWORKS® upgrade introduces engineered biological treatment using:
- Floating fine-bubble aeration (Oxiworks®)
- Controlled aerobic and anoxic zones
- Integrated secondary clarification
- Defined sludge age and MLSS concentration
This converts the lagoon from a passive treatment system into a fully controlled activated sludge process.
Lagoon aeration systems often suffer from poor oxygen transfer efficiency and dead zones. The Oxiworks® floating aeration system provides:
- High oxygen transfer efficiency
- Continuous mixing through natural movement
- Lower energy consumption than fixed aeration
- Uniform distribution of oxygen throughout the basin
This ensures stable nitrification, improved BOD removal, and consistent biological activity.
A lagoon upgraded to BIOWORKS® can achieve:
- Complete nitrification
- Biological denitrification through alternating aerobic/anoxic phases
- Biological phosphorus removal (Bio-P) when required
These capabilities allow the upgraded system to meet modern nutrient limits without major structural changes.
Key Components of a Lagoon Upgrade
The existing lagoon becomes the main activated sludge basin. BIOWORKS® evaluates:
- Basin geometry
- Depth and volume
- Existing inlet/outlet structures
- Sludge accumulation
- Hydraulic profile
Minimal civil work is typically required—most upgrades focus on mechanical and process improvements.
The Oxiworks® system is deployed across the lagoon surface. Benefits include:
- No need for basin draining
- No underwater piping
- Easy installation and maintenance
- Self-propelled movement for improved mixing
By cycling air supply to the floating aeration headers, the lagoon can operate with:
- Aerobic zones for BOD removal and nitrification
- Anoxic zones for denitrification
- Optional anaerobic Bio-P zones upstream
This zoning is achieved without internal walls or major construction.
A lagoon upgrade includes a crossflow clarifier or other clarifier depending on site conditions. This provides:
- Reliable solids-liquid separation
- Stable sludge recycling
- Controlled MLSS concentration
- Consistent effluent quality
Extended aeration reduces sludge production, but lagoon upgrades often include:
- Sludge removal planning
- Sludge storage or dewatering options
- Long sludge age for stable operation
Performance Improvements After Upgrade
A lagoon upgraded to BIOWORKS® typically achieves:
- BOD < 10 mg/L
- TSS < 10 mg/L
- Ammonia < 1–2 mg/L
- Total phosphorus < 1 mg/L (with Bio-P)
- Seasonally stable performance
- Lower energy use than conventional aeration systems
- Reduced operator burden
These improvements allow lagoon facilities to meet modern discharge permits without building a new treatment plant.
Operational Advantages
- Simple operation with minimal operator intervention
- High process stability due to long sludge age
- Lower maintenance because floating aeration avoids submerged mechanical components
- Easy access to aeration equipment from the surface
- Scalable design for future flow increases
Why BIOWORKS® Is Ideal for Lagoon Retrofits
BIOWORKS® specializes in lagoon conversions and extended aeration systems. The combination of:
- Oxiworks® floating aeration
- Long sludge age
- Integrated clarification
- Biological nutrient removal
Creates a treatment process that is robust, energy-efficient, and cost-effective—perfect for upgrading aging lagoon infrastructure.