Lagoon & Stabilization Pond Sizing Calculator - Facultative, Aerated, and Storage Lagoon Checks
Size wastewater lagoons based on BOD loading, climate zone & detention time requirements
Check facultative, aerated, and storage lagoon planning inputs from entered flow, influent BOD, climate zone, geometry, and storage period. Outputs include local area, volume, detention, earthwork, and aeration placeholders, plus source warnings for state criteria, permit limits, site data, liner requirements, and qualified review.
Check detention time separately when you have measured cell volume and flow data
Detention Time Calculator →Check sludge production prompts before planning lagoon cleanout scope
Sludge Production & Disposal Cost Calculator →Review disinfection math only after permit limits and approved CT or UV basis are known
Chemical Dosing Calculator →Check outfall weir flow after discharge structure geometry is verified
Weir Flow Calculator →How It Works
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Enter Screening Inputs
Input flow rate, influent BOD concentration, optional effluent target, and population context. Use measured plant or planning-flow data where available.
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Select Lagoon Type and Climate
Choose facultative, aerated, or storage lagoon and select a climate zone. Treat the local loading rows as placeholders until current state criteria are verified.
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Configure Cell Layout
Set number of cells, operating depth, freeboard, and side slope ratio. Confirm cell arrangement, hydraulics, liner, and berm requirements with project sources.
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Review Planning Results
Review surface area, volume, detention, local range flags, approximate cell dimensions, earthwork calculator, and source warnings before any design use.
Built For
- Small towns screening early lagoon wastewater options
- Engineers comparing preliminary expansion scenarios before source reconciliation
- Operators sanity-checking entered flow and BOD assumptions for further review
- Rural communities framing questions for lagoon versus mechanical treatment planning
- Project teams collecting source gaps before a formal design submittal
Assumptions
- Organic loading rates are local screening bands and are not represented as current state-approved criteria
- Influent BOD and TSS are user-entered and assumed constant (no seasonal or diurnal variation applied)
- Lagoon operating depth follows local screening ranges only
- Side slope ratios are user-selectable and must be verified against geotechnical, liner, safety, and reviewing-authority criteria
- Multi-cell configurations assume equal cell sizing and do not model actual series hydraulics, baffling, or short-circuiting
- Earthwork volume is estimated from prismoidal formula using top and bottom dimensions with the selected side slope
- Evaporation and seepage losses are not included in the hydraulic detention time calculation
Limitations
- Does not model algae growth, DO profiles, ammonia, nutrients, TSS, pH, or seasonal treatment performance
- Wind-induced mixing effects and thermal stratification in deep lagoons are not modeled
- Does not evaluate liner requirements (clay, HDPE, GCL) based on site soil permeability and groundwater protection standards
- Odor potential from overloaded primary cells or anaerobic conditions is not assessed
- Does not account for sludge accumulation over time, which reduces effective volume and treatment capacity
- Setback distances, floodplain, groundwater protection, liner approval, and permit conditions are jurisdiction-specific and not calculated here
References
- EPA-WASTEWATER-POND-SYSTEMS-2011 - EPA pond-system design and operations source pointer
- TEN-STATES-WASTEWATER-2014-SOURCE - Ten States wastewater standards source pointer; current state adoption must be verified
- EPA-SECONDARY-TREATMENT-STANDARDS-2026 - EPA secondary-treatment regulatory context
- WEF-MOP8-7TH-SOURCE - licensed wastewater design reference pointer only
- NRCS-POND-LINING-COMPACTED-SOIL-520-SOURCE - liner and seepage warning context
- State design standards and permit conditions vary; verify with the reviewing authority
Frequently Asked Questions
Learn More
What Your Sludge Actually Costs
How to estimate sludge production from plant loading, the real differences between dewatering methods, and why disposal costs only go up.
Why Small Towns Still Use Lagoons
Capital cost context, loading-rate source gaps, winter performance risks, and lagoon planning questions to verify before design use.
Pond & Pit Pump-Out Source Boundaries
How to calculate pond and pit volume for frustum and flat-bottom shapes, estimate fill/drain time, reverse-solve for required pump flow, and plan dewatering safely.
Pond Evaporation & Water Loss: Calculating Makeup Water Needs
How to estimate pond evaporation, seepage by liner type, seasonal water budgets, and required makeup water flow rate and annual cost.
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Detention Time Calculator
Calculate hydraulic detention time for any basin, tank, or lagoon and check against regulatory minimums. Supports rectangular and circular tanks with dead zone correction for actual vs theoretical retention time.
Disinfection CT Value Calculator
Calculate CT values for chlorine disinfection and verify EPA Surface Water Treatment Rule compliance. Check Giardia and virus log inactivation credits based on residual, contact time, temperature, and pH.