Nutrient Management Act, 2002: Handling Runoff from Outside Livestock Areas and Solid Manure Storages

Agdex#:	720/400
Publication Date:	04/05
Order#:	05-027
Last Reviewed:	09/06
History:
Written by:	Robert P. Stone, Engineer/OMAFRA

Table of Contents

1. Introduction
2. Runoff Quality
3. Runoff Volume
4. Runoff Management Systems
   • Roofed Storage or Roofed Outside Yard
   • Collection and Storage System
   • Vegetated Filter Strip System
   • Permanently Vegetated Area
5. Facilities Requiring Runoff Management

Introduction

Uncovered manure storage facilities, livestock yards and permanent outdoor confinement areas will be subject to rainfall and snowfall events. These liquids and any others, such as urine, that are not absorbed by the manure are typically called runoff when they leave the facilities. Most people recognize runoff as a brown or black liquid. This Factsheet discusses runoff components and provides options for Ontario farmers to manage runoff from livestock yards and manure storage facilities.

For the purposes of Ontario Regulation 267/03, as amended, under the Nutrient Management Act, 2002 (the "Regulation") the term "runoff" means a liquid that

• has come into contact with manure in a permanent nutrient storage facility, temporary field nutrient storage site, outdoor confinement area or farm animal yard lined with concrete or other paving material of equal or lesser permeability
• may contain components of manure in solution or suspension and
• is no longer contained in the permanent nutrient storage facility, temporary field nutrient storage site, and outdoor confinement area or farm animal yard

Many of the terms used in this definition are also defined in Section 1 of the Regulation.

Runoff may flow over the ground and contaminate surface water as defined in Section 2 of the Regulation or leach to groundwater where it may degrade water quality. Concerns with runoff are related to chemical contamination, i.e. nitrates, phosphates, and/or biological contamination, i.e. bacteria, viruses and parasites.

Farmers who are subject to the Regulation are required to manage runoff so that surface water and groundwater are not negatively impacted by it. Water quality is also protected under the Ontario Water Resources Act and the Environmental Protection Act.

The Regulation requires a runoff management system (Figure 1) capable of handing all runoff generated by the facility for a 240-day period, (with some exceptions) for all permanent outdoor confinement areas (s. 81), and all permanent solid nutrient storage facilities and paved farm animal yards (s. 81).

Figure 1. Runoff can be stored in an open-top concrete tank.

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Runoff Quality

Runoff may have solid and liquid components. Typically, urine, washwater and contaminated water make up the liquid portion, while the solid portion consists of manure, bedding, feed and soil.

The constituents in runoff can be broken down into three categories as shown in Table 1.

¹Although the long-term effects of nitrates on human health are not known, it is not a good practice to drink water containing nitrates. The recommended maximum acceptable concentration of nitrate as stipulated by Ontario Drinking Water Standards is 10 mg/L.

²Phosphorus increases algae growth in surface water. When the algae dies and decays in surface water it uses up oxygen, resulting in potential fish kills.

³Pathogenic bacteria such as E. coli can cause disease in humans and livestock when they get into drinking water supplies.

Many of the same contaminants that are found in runoff may also be found in liquid manure. Typically, runoff has a very low solids content (often referred to as dry matter content) resulting in considerably lower constituent levels than liquid manure.

Table 2 provides typical constituent levels for runoff and liquid dairy manure. The values show that runoff is a very diluted and lower risk material as compared to liquid dairy manure.

* A recognized value in Ontario for liquid dairy manure.

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Runoff Volume

Section 81 of the Regulation states that permanent outdoor confinement areas, permanent solid nutrient storage facilities and paved farm animal yards must be equipped with a runoff management system that handles all the runoff generated by the facility. Current versions of OMAFRA's NMAN Computer Software can be used to calculate the volume of runoff. This volume is dependent on the factors outlined in Table 3.

In general, runoff volumes from permanent outdoor confinement areas, permanent solid nutrient storage facilities and paved farm animal yards are much higher than anticipated by the farmer. For example, a permanent outdoor confinement area can produce up to 36.6 cm (1.2 ft.) of depth of runoff per square foot of the outdoor confinement area over a 240-day period. This runoff amount depends on the dry matter content of the manure and manure quantity in the confinement area during this period. A significant percentage of the liquid that falls on a permanent outdoor confinement area, a permanent solid nutrient storage facility or paved farm animal yard, can be absorbed by solid manure. However, when there is a small amount of solid manure in the confinement area more runoff will result.

Before constructing a runoff management system, direct all clean water away from the permanent outdoor confinement area, permanent solid nutrient storage facility or paved farm animal yard. Clean water is rain, snowmelt or other water that has not come in contact with manure. Directing clean water away from the facility will reduce the volume of contaminated runoff that has to be handled and keep the facility drier, making it more desirable to work in.

Surface water moving over the ground may be diverted by installing berms and ditches, while eavestroughs on buildings can direct roof water away from permanent outdoor confinement areas, permanent solid nutrient storage facilities and paved farm animal yards (Figure 2).

Figure 2. An eavestrough system directs clean water away from the outside yard.

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Runoff Management Systems

When planning your manure storage facility, livestock yard or outdoor confinement area, consider how runoff is to be managed. If the facility or area is not covered, provide a small slope (1%-2%) on the floor to one corner to allow the runoff to be collected/managed at one location. A screening system, e.g. picket fence, and/or a small settling area at this low point will screen the solids and allow them to settle out. The liquids will drain to the runoff management facility.

There are four runoff management systems commonly used on farms.

1. Roofed Storage or Roofed Outside Yard
2. Collection and Storage System
3. Vegetated Filter Strip System
4. Permanently Vegetated Area

A brief description of each runoff management system follows.

1. Roofed Storage or Roofed Outside Yard

Constructing a roof over a permanent solid nutrient storage facility, permanent outdoor confinement area or paved farm animal yard will prevent rain and snow from entering the facility (Figure 3). The advantage of a roofed system is that it reduces runoff volume since rain and snowmelt do not need to be stored or treated. Additional water may also change the dry matter content of the manure, which may change the type of treatment system used.

Figure 3. Placing a roof over a permanent solid nutrient storage facility eliminates runoff.

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2. Collection and Storage System

Runoff may be collected and stored in a permanent liquid nutrient facility or in a separate storage facility before it is spread on cropland as a nutrient source. The storage facility may be constructed of concrete, steel or earth. See Sections 64 to 67 and 71 of the Regulation for the requirement regarding the need to employ a professional engineer or professional geoscientist for siting, design and construction of the storage facility. The initial construction or expansion of a permanent liquid nutrient storage facility must comply with the Regulation.

The runoff management systems above, e.g. roofed storage or roofed outside yard and collection/storage system will have to be sited to meet municipal by-law requirements. In most cases, the siting will be calculated based on the Minimum Distance Separation II (MDS II) formula. Contact the municipality in which the facility is to be located about siting prior to applying for a building permit.

The following siting requirements for runoff management systems must be met under Section 63 of the Regulation:

• 15 m from a ≥15 m deep drilled well with watertight casing to a depth of ≥6 m below ground level
• 100 m from a municipal well
• 30 m from any other well (if storing agricultural source materials)
• 90 m from any other well (if storing non-agricultural source materials)
• 15 m from field drainage tiles or piped municipal drains
• remove all drainage tiles within a 15 m zone around the collection or storage system and redirect field drainage system or piped municipal drains away from facility
• if a drainage system is constructed within the 15 m zone of the facility, the system must use non-perforated pipe with all subsurface joints sealed unless the collected water discharges to a treatment system or to foundation drains of the storage facility equipped with an observation and shut-off station
• ≥50 m flow path length from storage to nearest top of bank of surface water or tile inlet
• no construction in 1 in 100 year flood lines unless a permit is issued under Section 28 of the Conservation Authorities Act

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3. Vegetated Filter Strip System

A vegetated filter strip system means the complete system required to treat runoff and includes temporary storage, screening, transport of runoff including a pump if required, and the vegetated filter strip. The vegetated filter strip, or infiltration area, is a densely vegetated strip of land, engineered and constructed to accept and manage agricultural runoff and washwater by settling, filtration, dilution, and absorption of pollutants and infiltration into the soil. The vegetated filter strip system is one of several options that farmers may choose to use to handle runoff and other agricultural washwaters.

Runoff is collected and stored in a settling basin, which could be:

• a curbed area on the paved outdoor yard
• a curbed pad adjacent to the permanent solid nutrient storage facility or
• a separate external basin

From the settling basin, the runoff either flows by gravity or is pumped to the vegetated filter strip. A perforated distribution pipe is located across the top end of the filter strip to distribute the runoff along the width of the strip (Figure 4). Treatment occurs as runoff moves down the strip. Approval under the Ontario Water Resources Act may be required from the Ministry of the Environment for installation of a vegetated filter strip system. For more information on design and siting of the vegetated filter strip system visit the OMAFRA website.

Figure 4. Runoff may be transferred to a vegetated filter strip for treatment.

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4. Permanently Vegetated Area

A permanently vegetated area is a permanent pasture, permanent hayfield or forested area where the runoff flows through. The area where the runoff flows is referred to as a flow path, which can be a surface pathway or depression that conducts the runoff away from the facility. The flow path is a permanently vegetated area that is not tiled. Treatment occurs as the runoff moves along the length of the flow path.

A flow path cannot always be used as the runoff management system. Certain criteria related to the solid nutrient storage facility, paved farm animal yard or permanent outdoor confinement area would have to be met before a flow path can be installed. The dry matter content of the manure is one of the criteria that must be considered before a flow path is constructed. Drier manure has less potential for runoff, therefore a shorter length of flow path to surface water is permitted.

A minimum flow path length from the facility to surface water must be met. The flow path may go directly from the facility to surface water, meander back and forth or be located parallel to a berm along surface water to achieve the minimum length required (Figure 5).

All flow paths in Figure 5 are 150 m long.

Figure 5. A flow path can be formed in different ways to achieve the minimum length required.

Flow Path Siting

A flow path must be located to meet the following conditions:

• 0.5 m minimum soil depth
• ≥3 m from field tile drains
• ≥100 m from municipal wells
• ≥15 m from drilled well
• ≥30 m from any other well

Further details regarding permanently vegetated areas may be found in Section 81 of Ontario Regulation 267/03, as amended.

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Facilities Requiring Runoff Management

Under Section 81 of the Regulation, permanent outdoor livestock confinement areas, permanent solid nutrient storage facilities and farm animal yards paved with concrete or other suitable material require a runoff management system that will handle all of the runoff generated by the facility.

Permanent Solid Nutrient Storage Facilities

Section 81(1) of the Regulation requires that a permanent solid nutrient storage facility be equipped with a runoff management system capable of handling all of the liquid generated by the facility.

Options for Handling Runoff

Refer to Table 4 for specific legal requirements relating to runoff control options.

*All options include a requirement to divert up-slope water away from the facility.
**The solid manure storage floor area < 300 m²

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Paved Livestock Yards³

Section 81(2) of the Regulation requires that a livestock yard paved with concrete or other acceptable material, other than a permanent outdoor livestock confinement area, be equipped with a runoff management system capable of handling all of the liquid generated by the facility.

Options for Handling Runoff ¹

• A roof over the paved yard
• Runoff collection and storage system that meets standards under Part VIII of the Regulation, i.e. concrete/steel tank or earthen storage
• Vegetated filter strip system
• Flow path - can be used if the facility meets the following conditions: ²
  • dry matter content of manure ≥30%
  • flow path length (paved livestock yard to surface water or tile inlet) must be:
    • minimum of 150 m for manure with dry matter content of ≥30%
    • minimum of 50 m for manure with dry matter content of ≥50%

¹ All options include a requirement of diverting up-slope water away from the facility.

² See "Flow Path Siting" section in this Factsheet for requirements on locating the flow path system.

³ Paved livestock yards typically are "exercise" yards where no feeding or watering occurs or where the animals are present for less than 200 days per year.

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Permanent Outdoor Confinement Areas

Section 81(3) of the Regulation requires that a runoff management system must be provided for all permanent outdoor confinement areas (Figure 6). The runoff management system must be composed of natural or manufactured runoff collection, treatment and containment devices that are capable of preventing, collecting, treating or containing runoff. One may select from the options presented below keeping in mind that the former objective of preventing, collecting, treating or containing runoff must be met.

Figure 6. Runoff is generated from permanent outdoor confinement areas

• A roof over the confinement area
• Vegetated filter strip system
• Runoff collection and storage system that meets standards under Part VIII of the Regulation, i.e. concrete/steel tank or earthen storage
• A flow path can be used if the following conditions are met:²
  • <150 nutrient units are generated annually in the area
  • maximum outdoor confinement area of <2,000 m² per flow path.
  • for outdoor confinement area <500 m², use minimum flow path length of 100 m
  • for outdoor confinement area ≥500 m² to <2,000 m², use minimum flow path length of 150 m

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Overview of Permanent Outdoor Confinement Area, Permanent Solid Nutrient Storage Facility and Paved Farm Animal Yard and Runoff Options

Text version

This Factsheet reviewed by Jake DeBruyn, P. Eng., Engineer, New Technology Integration, Environmental Policy and Programs Branch, OMAFRA, Guelph and Peter Doris, Nutrient Management Specialist, Nutrient Management Branch, OMAFRA, Brighton.

Do you know about Ontario's new Nutrient Management Act?

The provincial Nutrient Management Act (NMA) and the Regulation 267/03, as amended, regulates the storage, handling and application of nutrients that could be applied to agricultural crop land. The objective is to protect Ontario's surface and groundwater resources.

Please consult the regulation and protocols for the specific legal details. This Factsheet is not meant to provide legal advice. Consult your lawyer if you have questions about your legal obligations.

For more information on the NMA call the Nutrient Management Information Line at 1-866-242-4460, e-mail nman.omafra@ontario.ca or visit the OMAFRA website.

Factsheets are continually being updated so please ensure that you have the most recent version.

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