This document discusses best practices for managing deep manure pits on livestock farms. It emphasizes that the top priorities for pit management are safety, indoor air quality, environmental protection, and maximizing the fertilizer benefits of manure nutrients. Some key recommendations include ensuring good pit ventilation, especially during agitation and pumping; monitoring pit levels; maintaining biosecurity; and properly sampling and applying manure nutrients according to a nutrient management plan. The document also cautions about potential issues with new pit construction if proper protocols are not followed.

1. Solid Solutions for Your Pit
Sponsored by Elanco Animal Health
Ted Funk, PhD, PE
Funktioneering.com

2. Introduction
 What’s a “deep” pit and why should I care?
 What could possibly go wrong?
 How can I make my pits work better?
 How can I maintain biosecurity for my buildings with
pits?
 How can I maximize the fertilizer benefits from my pits?
 Some new pit construction booboos

3. A “deep pit” is:
 A container for a liquid that must be regarded as a
potential pollutant
 A reservoir that allows for timely placement of
nutrients on cropland
 A conservation component that preserves the quality
and quantity of manure nutrients for use by crops
 A structure that acts as a foundation for building floors
and walls
 A component of a building’s ventilation system

4. “Timely” placement? Who’s asking?

5. Conserving nutrients…?

6. Foundation for…what?
Photo credit: Illinois Department of Agriculture

7. Slats showing their age? Not like
diamonds…they don’t last forever.
Slat end
cracks
Flaking or
spalling
Slat
Cracks exposing
reinforcing steel
Beam
Beam
ledge
failure

8. Pit ventilation?—I’ll get back to
you on that…

9. The bigger the reservoir, the
bigger the problem, if….
Sure, this is a dairy, but the issues apply to us all.

10. Priorities in pit management
Safety & indoor air quality
• Protect animals and workers from toxic gases,
maintain good atmosphere in building
Environmental protection
• Inspect pits, monitor levels, manage capacity
Best use of nutrients
• 4 R’s of nutrient management: Right type,
right amount, right time, right placement

11. Safety issues
 Good ventilation of deep pits
 Agitation and gas emissions
 Foaming pits

12. Pit ventilation: How good is it?
 Practical limits to fan “reach”—15 feet?
 Structure limits on fan placement
 Ventilation stages may limit number of fans running
 Variable speed fans are REALLY variable…and
unpredictable
 Underfloor ducts—impractical?
…bottom line: pit ventilation is not really that efficient.
Put in plenty.

13. Pit ventilation—the critical times
Low contribution to whole vent rate
• Small pigs, cold weather
Manure level high, close to floor
• Near time to pump out pit
Very high concentrations of toxic and/or combustible gases
• Pit agitation prior to, during pumping
• Also possible when there is deep foam present

14. Death by pit gas: We study and study,
but still lose animals every year….
Zhao et al., 2005. Ventilating Confined Manure Storages: Progress Report, ASABE Paper No. 055019.

15. Agitation and Pumping
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Keep people out of building
Ignition sources off
Gas supply turned off
Ventilate properly
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Fans on 20-30 cfm/pig
Curtains closed if wind not blowing
Ceiling inlets open
Pumpouts sealed
Mixing fans if available
No agitation . . . if possible
No agitation until manure is 2’ below slats
If possible, agitate intermittently
No rooster tailing

16. Foaming pits—an old problem,
and a whole ‘nuther topic

17. Foam contains biogas.
Go ahead—try this at home!

18. …so where’s your pit ventilation now?

19. Tough luck, poor planning, whatever….
The pit’s full, and it’s August.
What’s your plan?

20. Biosecurity measures
 Well, we thought we were pretty good at biosecurity.
Then PEDV….

21. Biosecurity—general information
 Biosecurity Guide for Pork Producers
 National Pork Board website

22. Details: Manure pit pumpout port.
Management during manure removal?
Sealed lid, liquid trap panel at wall

23. Manure samples info
 Best sampling done during land application
 Stratification of solids, nutrients: why not sample the pit
without agitating it?
top
middle
bottom
Phosphorus as P2O5, lb/1000
gal
0.0
5.0 10.0 15.0 20.0 25.0 30.0

24. Pit level monitoring and
management
 Water management—see NPB study “Water
Consumption and Conservation Techniques Currently
Available for Swine Production”, NPB #09-128
 80% of the water used in a building is drinking water,
so–
 Use good drinkers
 Stop the leaks
 Save big $$ on manure spreading costs

25. Pit level monitoring and
management
 Electronic liquid level—what are you using?
 Mechanical liquid level
 Weekly level monitoring required by regulation (US
EPA)—how are you doing that?
 Water meters and what they can do for you

26. Recordkeeping
 Water metering—not just for noting leaks
 Decreased intake: Onset of disease in the building?
 Insufficient intake with large pigs, hot weather: Indications
of plumbing restrictions?
Photo: www.edcheung.com

27. Why ASSUME you have room in
the pit?
 Check water meters daily and log
the readings
 Measure manure depth in pit
weekly, and record
 AFTER pumpdown, check for solids
& unrecoverable liquids remaining

28. Tools for updating and managing
your NMP
 Smart phone apps?
 UMO nutrient management
software and MMP extensions

29. Manure nutrient economics:
Valuing liquid manure
 Fertilizer component replacement?
 Target field fertility requirements—don’t count $$ for
something that is not needed
 Use realistic haul & apply cost credits
 http://extension.missouri.edu/p/G9330

30. Pit additives? Claims:
Reduce manure odor
Reduce manure toxic gases
Manage solids and crust
Retain nutrients and make more plant available
Show me.

31. New construction
 What can go wrong with pouring a pit?
 Construction—see Illinois Dept of Ag examples
 Perimeter tiles
 Wall penetrations
 Water stops

32. Concrete mix and placement quality
control—choose your contractor
carefully
Photo credit: Illinois Department of Agriculture

33. Honeycombing
Prevent by
vibrating or
rodding during
placement
Use proper mix
Photo credit: Illinois Department of Agriculture

34. Waterstop “Blowout”
Exposed Waterstop
Photo credit: Illinois Department of Agriculture

35. Improper installation:Expandable
waterstops placed in standing water
Photo credit: Illinois Department of Agriculture

36. Pouring in the rain – Standing
Water. They’ll probably get to do
this one over.
Photo credit: Illinois Department of Agriculture

37. Debris in a poured wall—Guess
who gets to dig this one out!
2x4
Photo credit: Illinois Department of Agriculture

38. Cold Weather / Snow
Plan for
conditions
Proper Mix
Protect Pour
Blankets
Leave Forms
Speed up the
curing process
Photo credit: Illinois Department of Agriculture

39. Floor Caps—If at first you don’t
succeed….
Photo credit: Illinois Department of Agriculture

40. Perimeter Drainage Tubing—
required in some situations
Photo credit: Illinois Department of Agriculture

41. Perimeter Drainage Tubing
Sampling
port
Photo credit: Illinois Department of Agriculture

42. Floor cracked by heavy
equipment. “Secure” liquid
container?
Photo credit: Illinois Department of Agriculture

43. Penetration by water pipe. Don’t look
now, but that grout is going to disappear,
and then…so is the manure!
Photo credit: Illinois Department of Agriculture

44. Proper Backfill—one of the
required details, sign of a good
contractor
Photo credit: Illinois Department of Agriculture

45. But enough about construction.
Back to managing what you
have:

46. Summary—your priorities for
deep pit management
Safety & indoor air quality
• Protect animals and workers from toxic gases,
maintain good atmosphere in building
Environmental protection
• Inspect pits, monitor levels, manage capacity
Best use of nutrients
• 4 R’s of nutrient management: Right type,
right amount, right time, right placement

47. Last words
 Be safe
 Track freeboard
 Have a contingency plan for land application
 Take credit for nutrients
Sponsored by Elanco Animal Health