Infosheet #10 Silage Storage

Table of Contents

• Introduction
• Location
  • 10-1 Distance from silage storage to nearest surface water
  • 10-2 Distance from silage storage to water well
• Condition of Silo (tower or horizontal)
  • 10-3 Floors, walls and foundations
  • 10-4 Cover
  • 10-5 Lining (tower)
• Silage Moisture
  • 10-6 Silage - horizontal silo
  • 10-7 Silage - tower silo
  • 10-8 Distance from balage (under 75% mc) storage to nearest surface water
• Collection of Seepage
  • 10-9 Storage and collection, dilution and spreading of seepage

Introduction

This infosheet provides background to Worksheet #10 of the Environmental Farm Plan Workbook. It outlines options you could adopt to address problem areas in your operation. In most cases you'll need more information before implementation: please refer to the resource materials listed in the infosheet, and consult OMAFRA Environmental Farm Plan (EFP) Technical Advisors.

All options are classed as Actions or Monitoring. Actions address the areas of concern identified, and will change the EFP rating to (3) or Best (4). Monitoring is an alternative only in special circumstances and is explained in the infosheet when and how it can be used.

At the request of the Ontario Farm Environmental Coalition, consisting of Ontario Federation of Agriculture, Christian Farmers Federation of Ontario, AGCare, and the Ontario Farm Animal Council, the following people contributed to the development of Infosheet #10:

Bob Stone, OMAFRA (Co-chair)
Steve Clarke, OMAFRA (Co-chair)
Murray Blackie, MOEE
Doug Dickie, OMAFRA
Bob Kerr, Ontario Cattlemen's Association

Technical Editing Committee:
Brent Kennedy, OMAFRA
Jim Myslik, OMAFRA
Bob Stone, OMAFRA

The following people contributed to the revision (2004) of Worksheet #10;

Bob Stone, OMAFRA (Co-chair)
Steve Clarke, OMAFRA (Co-chair)
Scott Abernethy, MOE
Christoph Wand, OMAFRA
Joel Bagg, OMAFRA

Technical Editing Committee:
H.J.Smith, OMAFRA
Jim Myslik, OMAFRA
Bob Stone, OMAFRA

OMAFRA = Ontario Ministry of Agriculture, Food and Rural Affairs
MOE = Ontario Ministry of the Environment

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Location

Issue: 10-1 Distance from silage storage to nearest surface water

The greater the distance between the silage storage and surface water, the less chance there is of contaminating surface water supplies. Steeply sloping topography and heavy soil will increase the chance for contaminated runoff to reach surface water.

What can you do?

Option #1 - Action

Relocate silage storage an adequate distance from surface water:

• locate downslope from surface water where possible
• new storage location should change the final EFP distance rating to a (3) or better.

Option #2 - Action

Move surface water away from silage storage:

• a small watercourse could be redirected and moved farther away from the storage or moved underground through a non-perforated pipe system - make sure necessary approvals are received for this change
• new surface water location should change the final EFP distance rating to a (3) or better.

Option #3 - Compensating Factor

Increase the flow path distance between surface water and silage storage:

• earthen berms can be built that will redirect any seepage to run alongside the watercourse for a distance instead of running directly into it
• flow path distance should change the final EFP distance rating to a (3) or better.

Option #4 - Monitoring

For silage storages in good working condition that have, or will have within two years, a seepage collection system, monitor regularly - visually checking for leaks or overtopping of seepage storage.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Soil Erosion Manual, OMAFRA
• Best Management Practices Book: Manure Management, Order No. BMP 16, pg. 83-84

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Issue: 10-2Distance from silage storage to water well

The greater the distance between the silage storage and the water well, the less chance there is that seepage will collect in the vicinity of the well head and cause contamination. Also, if leakage out of the storage occurs to the ground water, contamination reaching the well is less likely if the well is located further away from the storage. The soil type, depth to water table and bedrock will also influence the contamination potential.

What can you do?

Option #1 - Action

Relocate silage storage an adequate distance away from water well:

• locate storage downslope of well if possible
• new storage location should change the final EFP distance rating to a (3) or better
• where the minimum separation distances cannot be attained due to site restrictions, seek guidance from MOE
• test well water for indicator bacteria at least three times a year, and once a year for other parameters (such as nitrate) until the new storage is built or existing storage is relocated.

Option #2 - Action

Relocate water well away from silage storage:

• make sure old well is properly removed from use (abandoned according to Ontario Regulation 903)
• new water well location should change the final EFP distance rating to a (3) or better
• where the minimum separation distance cannot be attained due to site restrictions, seek guidance from MOE
• test well water for indicator bacteria at least three times a year, and once a year for other parameters (such as nitrate) until the new water well is constructed
• investigate water well records in the area before constructing new water well.

Option #3 - Monitoring Well Water

For silage storages in good working condition that have, or will have within two years, a seepage collection system, test well water for indictor bacteria at least three times a year, and once a year for other parameters (such as nitrate):

• monitoring of well water is not a solution - if a test reveals contamination, have a plan of action in place to immediately identify and address the source of contamination
• if you have an EFP rating of (1), contact MOE for further guidance.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Water Wells and Groundwater Supplies, the Protection of Water Quality in Bored and Dug Wells, MOE, 2003 (3962e01)
• Water Wells and Groundwater Supplies, the Protection of Water Quality in Drilled Wells, MOE, (3961e01)

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Condition of Silo (tower or horizontal)

Issue: 10-3Floors, walls and foundations

The condition of the floors, walls and foundations of the silo will greatly affect the escape of seepage from the silo. Impervious floors will prevent the movement of seepage into the groundwater below. Structurally sound walls and foundations are also important for operator safety.

What can you do?

Option #1 - Action

Install impervious floors in silos and ensure that walls and foundations are structurally adequate with cracks sealed:

• a plastic barrier may be used in the floor of some silos, e.g., vertical silos, to prevent movement of seepage into the soil below
• consider a silo drainage system that allows any free liquid to drain to a collection system.

Option #2 - Action

Seal existing silo floor by caulking joints, cracks, etc. and ensure that walls and foundations are structurally adequate with cracks sealed:

• a brushed-on epoxy coating may be adequate if only hairline cracks exist
• consider a silo drainage system that allows any free liquid to drain to a collection system.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

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Issue: 10-4Cover

Silo roofs or covers prevent rainwater from entering the silage, help in preserving a quality silage, and also reduce the potential for producing seepage.

What can you do?

Option #1 - Action

Install a roof or cover on the silo to exclude rain and snow:

• ensure that the roof or cover is tight-fitting without leaks
• a roof or cover will also lower dry matter losses and reduce surface freezing and spoilage.

Option #2 - Action

Repair existing silo roof or cover to eliminate leaks.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

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Issue: 10-5Lining (tower)

Silage juices corrode the silo walls and foundations over time. A badly corroded silo wall increases the risk of seepage escape. Silo maintenance, in the form of relining the wall, has to be done at regular intervals to reduce the escape of the seepage and help prevent the potential ultimate failure of the silo.

What can you do?

Option #1 - Action

Reline the silo walls as required - no longer than a maximum 15-year period between relinings:

• the moisture content of the silage contributes most to the quantity of seepage produced, which is crucial to the life of the lining
• the seepage produced also depends on the material stored, its constituents (organic acid), and handling/storage conditions
• cementitious or liquid coatings may be used to reline silo walls - the selection will depend upon the condition of the wall interior after cleaning.

Option #2 - Action

Replace existing silo with a new silo:

• ensure that the interior silo wall is protected by applying an acid-resistant coating prior to use
• new silo location should meet the EFP distance rating of (3) or better.

Option #3 - Action

Have silo lining condition checked by qualified contractor at regular intervals, i.e. 6-15 years following silo relining.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Deterioration of Concrete Tower Silos, OMAFRA Factsheet Order No. 90-235
• Concrete Tower Silo Maintenance and Repair, OMAFRA Factsheet Order No. 90-236
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

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Silage Moisture

Issue: 10-6Silage - horizontal silo

The amount of silage seepage produced depends primarily on the moisture content of the silage. Additional water added to the silage in the form of rain or snow will produce additional seepage. Research indicates that materials stored at 65% moisture content or higher can produce seepage.

What can you do?

Option - Action

Harvest and store silage at a moisture content of 70 - 75% or less:

• storing at the above moisture content is ideal for the ensiling process.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

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Issue: 10-7Silage - tower silo

The amount of silage seepage produced depends primarily on the moisture content of the silage. The increased pressure on the silage with silos over 40 feet deep will also increase the amount of seepage produced. Research indicates that materials stored at 65% moisture content or higher can produce seepage.

What can you do?

Option - Action

Harvest and store silage at a moisture content of 60-65%, or less with silos having silage depth greater than 40 feet:

• storing at the above moisture content is ideal for the ensiling process.

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

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Issue: 10-8 Distance from balage (under 75% mc) storage to nearest surface water

Balage stored at lower than 75% mc can produce seepage. The greater the distance between the balage storage and surface water the less chance there is of contaminating surface water supplies.

For balage stored at 75% mc or greater, refer to question 10-9.

What can you do?

Option #1 - Action

Relocate balage storage an adequate distance from surface water:

• locate downslope from surface water where possible
• new storage location should change the final EFP distance rating to a (3) or better.

Option #2 - Compensating Factor

Increase the flow path distance between surface water source and balage storage:

• earthen berms can be built that will redirect any seepage to run alongside the watercourse for a distance instead of running directly into it
• flow path distance should change the final EFP distance rating to a (3) or better.

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Collection of Seepage

Issue: 10-9 Storage and collection, dilution and spreading of seepage

• tower and horizontal silos
• balage, if 75% mc or greater

Large amounts of silage seepage can be produced, especially if the silage is harvested and stored at higher-than-recommended moisture contents. Provide a system to handle seepage from silos and balage systems where the moisture content of the balage is 75% or greater.

Seepage can be the most polluting organic surface discharge that occurs on the farm. Because of the high biochemical oxygen demand of the seepage, it can be deadly to fish if it runs off to a stream.

What can you do?

Option #1 - Action

Install an adequately designed seepage collection and storage system:

• divert all surface water and rainfall away from the silage storage so it does not have to be collected/stored
• collect and store all silage seepage and spread effluent on cropland
• drainage system is required in silo floor to intercept seepage and transfer it to the storage.

Option #2 - Action

Install a collection sump at the silage storage location to intercept seepage. Transfer seepage by gravity or pump to an existing/proposed liquid manure or runoff storage:

• divert all surface water and rainfall away from the silage storage so it does not have to be collected/stored
• collect and store all silage seepage and spread effluent on cropland
• drainage system is required in silo floor to intercept seepage and transfer it to storage.

Option #3 - Action

Install a designed collection and storage system for low flow rates of silo seepage and construct a vegetated filter strip to intercept and treat diluted high flow seepage rates:

• a professional engineer must design the vegetated filter strip
• approval for installation of the vegetated filter strip must be obtained from the appropriate agency.

For More Information:

• How to Handle Seepage From Farm Silos, OMAFRA Factsheet Order No. 04-031
• Best Management Practices Book: Water Management, Order No. BMP 07, pp. 41-42

Infosheet Table of Contents

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