Lesson 43: Manure Storage

Environmental Stewardship Assessment:

The goal of this assessment is to help you confidentially evaluate environmental issues that relate to outdoor air quality. For each issue listed in the left column of the worksheet, read across to the right and indicate the statement that best describes conditions on your farm. If any categories do not apply, leave them blank.

Name of Operation:

Date:

1. Relative risk associated with alternative types of manure storage systems

Formed manure storage, earthen storage basin, or undersized anaerobic lagoon. Corresponding magnitude of risk

Properly sized anaerobic lagoon
OR
Partially covered manure storage
OR
Open lot runoff holding
OR
Dry manure storage where liquids are separated and drained to separated storage or absorbed by bedding.

Anaerobic digester or other treatment system is included with manure storage.
OR
Purple anaerobic lagoon
OR
Composted manure storage
OR
Manure is stored for less than one week before land application. Properly covered manure storage

2. Location of storage or lagoon relative to confinement animal housing (Dusty ventilation air moving across storage or lagoon surface picks up and transports additional odors.)

	Prevailing winds or ventilation fans direct building ventilation air across storage or lagoon surface.	Corresponding magnitude of risk
	Manure storage or lagoon is remotely located from animal housing. OR Prevailing winds or ventilation fans DO NOT direct building ventilation air across storage or lagoon surface.	Corresponding magnitude of risk

3. Manure surface

Manure surface is exposed and does not form a crust. Corresponding magnitude of risk

Storage is loaded below liquid surface,
AND
crust forms over only part of storage surface due to top loading, regular agitation, wind, or other factors.
OR
Crop residue cover is in place at least six months of year during periods of greatest odor concerns.
OR
Manure surface is partially covered by crop residue, plastic membrane, or other type of cover.

Storage is loaded below liquid surface,
AND
stored manure forms undisturbed crust over the entire surface.
OR
Manure is held in enclosed manure storage tank or completely covered year-round with crop residue, plastic membrane, or other type of cover. Surface aeration maintains oxygen concentration of 1 mg/liter or greater.

4. Agitation during emptying

Storage is aggressively agitated by manure stream directed above manure surface.
Corresponding magnitude of risk

Storage is aggressively agitated by manure stream directed below manure surface.

No agitation use during storage emptying.

Anaerobic lagoon only

5. Signs of improved treatment for reducing odors… Active lagoons stabilize odors.

Lagoon is dark brown or black in color and shows few signs of active bubbling during warm weather. Corresponding magnitude of risk

Lagoon is dark brown or black and is actively bubbling from spring through fall.

Lagoon is maintained in aerobic state (1 hp of aeration capacity/150 finish hogs, 50 beef, or 30 dairy animals)
OR
Deep purple or red-colored lagoon

6. Permanent pool (or first stage of two-stage lagoon) Size…Large permanent pools dilute incoming manure and provide a better stabilization of odors.

Sizing of permanent pool is unknown or not sized according to standard engineering.
OR
Animal numbers have increased above designed capacity for lagoon. Corresponding magnitude of risk

Permanent pool is sized following standard engineering recommendations.

Permanent pool is sized for odor control (twice standard engineering recommendation).

7. Permanent pool management…

A permanent pool of 1/3 of the total volume or less is maintained. Corresponding magnitude of risk

A permanent pool is maintained that is at least 50% of the overall storage volume.

Markers are used to identify “Stop Pumping Point” for maintaining permanent pool,
AND
permanent pool never drops below marker.

8. Lagoon loading… Frequent feeding is preferred to infrequent feeding.

Lagoon is loaded less frequently than weekly.
OR
Manure loading rates are highly variable. Corresponding magnitude of risk

Lagoon is loaded weekly with fairly similar quantities of manure.

Lagoon is loaded daily with fairly similar quantities of manure.

9. Lagoon unloading… Infrequent pumping causes buildup of salts and ammonia that can become toxic to anaerobic bacteria.

Lagoon is pumped infrequently or not at all due to evaporation and seepage generally matching liquid additions. Corresponding magnitude of risk

Lagoon is pumped annually to permanent pool marker. Infrequent measurements
OR
Reading between 8- 12 mmho/cm

Lagoon is pumped annually to permanent pool marker,
AND
in dry years, lagoon is pumped below permanent pool marker, and fresh water is added to marker.

10. Electrical conductivity…

No measurement
OR
Readings > 12 mmho/cm Corresponding magnitude of risk

Infrequent measurements
OR
Reading between 8- 12 mmho/cm

Quarterly measurements
OR
readings < 8 mmho/cm

Open lot runoff holding pond/Settling basins/Filter strips

11. Holding pond unloading

Holding pond is regularly more than half full. Corresponding magnitude of risk

Liquid is dispersed through a grass filter strip.
OR
When ground is not frozen, liquid is pumped out when ever ground will accept liquid without runoff. Pond is kept dry or with minimal liquid pools.

12. Draining of settling basins or channels

Liquid pools in settling basin often remain for multiple weeks. Corresponding magnitude of risk

Liquid pools in settling basin often remain for multiple days.

Liquids drain from settling basin, and a dry solid surface is observed within a few days after a storm event.

13. Drainage of open channels for transporting runoff

Liquid pools in open channels remain for multiple weeks. Corresponding magnitude of risk

Liquid pools in open channels often remain for multiple days.

All liquids drain from open channels.

Solid Manure

14. Stockpiling

Stockpiling often occurs near public roads or neighbors.
OR
Precipitation and seepage pools in vicinity of stockpile. Corresponding magnitude of risk

Stockpiling is avoided for most of year and harvested manure is directly land applied.
OR
Stockpiling is done in remote locations away from neighbors,
AND
all precipitation and seepage drains away from stockpile.

15. Composting

Wet manure is commonly stockpiled and never turned. Corresponding magnitude of risk

Crop residue is mixed with stockpile manure, but stockpile is not turned.

Only dry manure (< 45% moisture) is stockpiled.
OR
Crop residue is mixed with stockpiled manure to achieve < 45% moisture.
OR
Stockpiled manure is turned weekly to encourage composting until no additional heating occurs.

	Formed manure storage, earthen storage basin, or undersized anaerobic lagoon.	Corresponding magnitude of risk
	Properly sized anaerobic lagoon OR Partially covered manure storage OR Open lot runoff holding OR Dry manure storage where liquids are separated and drained to separated storage or absorbed by bedding.
	Anaerobic digester or other treatment system is included with manure storage. OR Purple anaerobic lagoon OR Composted manure storage OR Manure is stored for less than one week before land application. Properly covered manure storage

	Manure surface is exposed and does not form a crust.	Corresponding magnitude of risk
	Storage is loaded below liquid surface, AND crust forms over only part of storage surface due to top loading, regular agitation, wind, or other factors. OR Crop residue cover is in place at least six months of year during periods of greatest odor concerns. OR Manure surface is partially covered by crop residue, plastic membrane, or other type of cover.
	Storage is loaded below liquid surface, AND stored manure forms undisturbed crust over the entire surface. OR Manure is held in enclosed manure storage tank or completely covered year-round with crop residue, plastic membrane, or other type of cover. Surface aeration maintains oxygen concentration of 1 mg/liter or greater.

	Storage is aggressively agitated by manure stream directed above manure surface.	Corresponding magnitude of risk
	Storage is aggressively agitated by manure stream directed below manure surface.
	No agitation use during storage emptying.

	Lagoon is dark brown or black in color and shows few signs of active bubbling during warm weather.	Corresponding magnitude of risk
	Lagoon is dark brown or black and is actively bubbling from spring through fall.
	Lagoon is maintained in aerobic state (1 hp of aeration capacity/150 finish hogs, 50 beef, or 30 dairy animals) OR Deep purple or red-colored lagoon

	Sizing of permanent pool is unknown or not sized according to standard engineering. OR Animal numbers have increased above designed capacity for lagoon.	Corresponding magnitude of risk
	Permanent pool is sized following standard engineering recommendations.
	Permanent pool is sized for odor control (twice standard engineering recommendation).

	A permanent pool of 1/3 of the total volume or less is maintained.	Corresponding magnitude of risk
	A permanent pool is maintained that is at least 50% of the overall storage volume.
	Markers are used to identify “Stop Pumping Point” for maintaining permanent pool, AND permanent pool never drops below marker.

	Lagoon is loaded less frequently than weekly. OR Manure loading rates are highly variable.	Corresponding magnitude of risk
	Lagoon is loaded weekly with fairly similar quantities of manure.
	Lagoon is loaded daily with fairly similar quantities of manure.

	Lagoon is pumped infrequently or not at all due to evaporation and seepage generally matching liquid additions.	Corresponding magnitude of risk
	Lagoon is pumped annually to permanent pool marker. Infrequent measurements OR Reading between 8- 12 mmho/cm
	Lagoon is pumped annually to permanent pool marker, AND in dry years, lagoon is pumped below permanent pool marker, and fresh water is added to marker.

	No measurement OR Readings > 12 mmho/cm	Corresponding magnitude of risk
	Infrequent measurements OR Reading between 8- 12 mmho/cm
	Quarterly measurements OR readings < 8 mmho/cm

	Holding pond is regularly more than half full.	Corresponding magnitude of risk
	Liquid is dispersed through a grass filter strip. OR When ground is not frozen, liquid is pumped out when ever ground will accept liquid without runoff. Pond is kept dry or with minimal liquid pools.	Corresponding magnitude of risk

Net Survey Score:
Magnitude of risk:

	Liquid pools in settling basin often remain for multiple weeks.	Corresponding magnitude of risk
	Liquid pools in settling basin often remain for multiple days.
	Liquids drain from settling basin, and a dry solid surface is observed within a few days after a storm event.

	Liquid pools in open channels remain for multiple weeks.	Corresponding magnitude of risk
	Liquid pools in open channels often remain for multiple days.
	All liquids drain from open channels.

	Stockpiling often occurs near public roads or neighbors. OR Precipitation and seepage pools in vicinity of stockpile.	Corresponding magnitude of risk
	Stockpiling is avoided for most of year and harvested manure is directly land applied. OR Stockpiling is done in remote locations away from neighbors, AND all precipitation and seepage drains away from stockpile.	Corresponding magnitude of risk

	Wet manure is commonly stockpiled and never turned.	Corresponding magnitude of risk
	Crop residue is mixed with stockpile manure, but stockpile is not turned.
	Only dry manure (< 45% moisture) is stockpiled. OR Crop residue is mixed with stockpiled manure to achieve < 45% moisture. OR Stockpiled manure is turned weekly to encourage composting until no additional heating occurs.