Understanding MDS Calculations
Minimum Distance Separation (MDS) calculations determine how far a livestock barn or manure storage must be from neighbouring land uses. The calculations consider several factors specific to your operation and location.
Important Note
This page provides a general overview only. MDS calculations involve specific factors and variables that require professional assessment. We do not include exact formulas — contact us for a site-specific assesment.
Key Factors in MDS Calculations
Type of livestock (dairy cattle, beef cattle, swine, poultry, etc.)
Number of animals or total nutrient units
Type of manure system (solid, liquid, or mixed)
Type of manure storage (covered, uncovered, earthen, concrete)
Type of neighbouring land use (residential, commercial, institutional)
Whether the neighbouring area is a settlement or rural zone
Existing vs. proposed operation (MDS I vs. MDS II)
How MDS I Differs from MDS II
MDS I and MDS II use similar factors but apply them differently. MDS I protects new development from existing farms, while MDS II protects existing neighbours from new or expanding farms. The calculation approach and resulting distances can differ significantly.
Why Professional Help Matters
MDS calculations involve multiple variables and can be complex. An incorrect calculation can lead to barn placement that doesn't meet requirements, resulting in costly project delays or redesigns. A qualified professional can accurately assess your site and determine the correct MDS distances.
Tools
Can I Build a Barn Here?
Check whether a proposed barn location may be constrained by MDS, setbacks, or nearby land uses.
Use the Advanced MDS Calculator
Estimate detailed MDS-related setback planning for livestock barns and manure storage.
Calculate Nutrient Units
Estimate livestock nutrient units to help determine whether NMS or NMP requirements may be triggered.
Frequently Asked Questions
Do I need an NMS to build a barn in Ontario?
What are nutrient units and how does this relate to livestock?
When do I need both an NMS and an NMP?
How long does approval of a NMS or NMP take?