Nutrient Management Act, 2002 Constructing an Earthen Liquid Nutrient Storage Facility for ASM
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A permanent liquid nutrient storage facility made of earth, also referred to as an earthen liquid nutrient storage facility, is a relatively inexpensive way of storing liquid agricultural source material (ASM) if the soil conditions at the site are suitable.
Under the Nutrient Management Act, 2002 (NMA), new and expanding liquid nutrient storage facilities on farm units that generate more than 5 nutrient units of manure annually must meet minimum siting and construction standards as specified in Part VIII of Ontario Regulation 267/03 (the Regulation).
This Factsheet provides a general description of the legal requirements under the Regulation and other key factors to consider when expanding or constructing a permanent liquid nutrient storage facility made of earth for agricultural source materials (ASM). Figure 1 shows an example of an earthen storage facility.
Under the Regulation, permanent liquid nutrient storage facilities are structures that have:
Liquid nutrients include agricultural and non-agricultural source materials that have a dry matter content of less than 18% or have a slump of more than 150 mm using the slump test referenced in the Regulation. Agricultural source materials (ASM) include:
Non-agricultural source materials NASM) include:
Anaerobic digestion material is a liquid nutrient that can be an agricultural source material or non-agricultural source material, depending on the material treated in the digester. Anaerobic digestion material that meets all the following criteria is considered an agricultural source material:
Construction standards for a new or expanding permanent liquid nutrient storage facility for NASM are similar to ASM, with some exceptions. In addition to this Factsheet, see the OMAFRA Factsheet, Storage of Non-Agricultural Source Materials (NASM) in a Permanent Nutrient Storage Facility, for more details.
Before building an earthen liquid nutrient storage facility on an operation that generates more than 5 nutrient units of manure annually, consider the following:
The size of the earthen storage facility depends on several factors:
NOTE: Freeboard is an additional depth of storage required to deal with wave action due to wind and agitation and to provide a safety factor to address unexpected circumstances (e.g., excessive rainfall, leaks in water system, etc.). It is added to the calculated depth required for manure production and precipitation.
Amount of material generated
The amount of manure generated by farm animals varies between operations due to differences in herd management, including the amount of material used for bedding.
Determine the amount of manure from a livestock by taking measurements, or estimate it based on values provided in the Regulation. For example, measure the amount of manure generated by an existing operation during clean-out of barns and existing storage facilities. If estimating the amount, refer to the Nutrient Management Tables associated with the Regulation and the OMAFRA NMAN software for values of daily manure production for various livestock.
Size the storage facility based on the greater amount of manure measured at the farm or referenced in the Regulation, unless several years of reliable records of manure production indicate lower manure production.
Storage capacity required
Under the NMA, farm operations subjected to the Regulation because they are expanding or building a permanent nutrient storage facility or a structure to house livestock must provide a minimum storage capacity of 240 days for all nutrients generated and intended for storage at the farm (e.g., manure, washwater and runoff), with the following exceptions:
For example, a layer chicken operation that has an agreement with a broker who can provide 60 days of storage would only need a manure storage with a capacity of 180 days.
For example, a beef feeder operation that houses the animals for 180 days from November 1 until they go to pasture on May 1 would only need a manure storage with a capacity of 180 days.
For example, an operation with an NMP providing for land application of manure more often than every 240 days would not require a storage with a capacity of 240 days.
NOTE: This is used for liquid manure storages, if the number of farm animals on the farm unit has not increased since September 30, 2003.
For example, a dairy farm that transfers its manure off-site every 3 months to another farm unit, only requires a manure storage with a capacity of 3 months.
Also, take into consideration the storage capacity of all prescribed material received on the farm unit that is not directly applied to land (e.g., manure from other agricultural operations, NASM).
When siting a new earthen storage facility, consider the type of soil that is required for such a facility and the setbacks to wells, surface water, tile drains and neighbours. Some setback distances are specified in the Regulation, others are best management practices or required by the local municipality.
Setbacks specified in the Regulation
To minimize the risk of contaminating surface water and ground water, the Regulation requires that all of the following criteria are met:
For example, all perforated tile drains within 15 m of the perimeter of the facility must be removed unless they are required by the Engineer and properly installed as a foundation drain equipped with an observation and shut-off station. See O. Reg. 267/03, s. 63 (5).
Measure distances from the outer perimeter of the storage facility, including any associated berms. For detailed information on siting permanent nutrient storage facilities, see the OMAFRA Factsheet, Siting Regulations for Permanent Nutrient Storage Facilities, and the Regulation.
Setbacks not specified in the Regulation
Minimum Distance Separation (MDS II) formula:
MDS II determines the minimum separation distances between livestock facilities and/or permanent manure storages and neighbouring properties. It applies to all proposed new, enlarged or remodelled livestock facilities or manure storage facilities. Neighbouring properties include existing or approved development such as neighbouring houses, areas zoned residential, lot lines and road allowance.
MDS II is usually triggered when a building permit is required. Best management practices recommend that the MDS formula is used in all cases, including prior to expanding or constructing an earthen nutrient storage facility. This is supported by the Provincial Policy Statement, which indicates that "new land uses, including the creation of lots and new or expanding livestock facilities, shall comply with the minimum distance separation formulae."
The term "livestock facility" is defined in MDS II as:
See OMAFRA Publication 707, MDS Implementation Guidelines, for more information, or contact the local municipality, a nutrient management consultant or an OMAFRA engineer.
Other Municipal Setbacks
Contact the municipality for more information on other required setbacks, such as municipal drains, rights-of-way, etc.
Before expanding or constructing an earthen liquid nutrient storage facility, a nutrient management strategy (NMS), prepared by a certificate holder under Part X of the Regulation and approved by OMAFRA, is required.
The Regulation also has the following engineering requirements for new and expanding earthen liquid nutrient storage facilities:
Engineer's Commitment Certificate - The professional engineer(s) must sign the Engineer's Commitment Certificate prior to expanding or constructing an earthen liquid nutrient storage facility [O. Reg. 267/03, s. 71 (1)]. This is to ensure that the project conforms to the engineering requirements under the Regulation, where applicable. Get the standard form for the Certificate from the Forms Repository, or by contacting an OMAFRA engineer or environmental specialist.
Design - A professional engineer must design the construction or expansion, including any monitoring system. [O. Reg. 267/03, s. 71 (1)] Where required, incorporate provision for a liner and transfer system in the design and specifications. For example, if a pipe associated with a transfer system enters the nutrient storage facility, the design and specifications must include special considerations such as a reinforced opening and required flexible watertight gasket. The engineer who designs the storage facility should confirm whether a transfer system will enter the facility. If the design of a storage facility and the transfer system are not assigned to the same engineer, both engineers should communicate to ensure that the design of the storage facility takes into consideration the transfer system requirements under the Regulation.
Site investigation - A professional engineer or geoscientist must carry out a site characterization study to verify that the soil conditions at the site are suitable for an earthen storage facility. [O. Reg. 267/03, s. 64]
Site review - A professional engineer must perform a general review of the construction or expansion project. This review process ensures that the liquid nutrient storage facility is built in accordance with the drawings and specifications of the engineer. [O. Reg. 267/03, s. 71 (1)]
More details about the design requirements under the Regulation are presented below.
Site investigation - All new or expanding permanent liquid manure or nutrient storage facilities require a site characterization. This involves a minimum number of test holes to identify soil types and the presence of any aquifer or bedrock to determine the suitability of a site for a storage facility and any specific design requirements under the Regulation. For more details, see the OMAFRA Factsheet, Site Characterization Study for the Construction of Permanent Nutrient Storage Facilities, and the Regulation. [O. Reg. 267/03, s. 65, 67, 68]
General design - The storage facility, including any associated plumbing systems used to transfer manure or liquid nutrients, must be designed to minimize leakage, minimize corrosion and be structurally safe and sound. (O. Reg. 267/03, s. 71).
All earthen liquid nutrient storage facilities must be sited over a minimum of 2 m of hydraulically secure soils.
NOTE: Hydraulically secure soils must have a maximum hydraulic conductivity of 1 x 10-8 m/sec.
Under the Regulation, there are two types of earthen liquid nutrient storage facilities (see O. Reg. 267/03, s. 65):
For example, the soils that form the inner surface must be disked to a depth of 150 mm and recompacted to meet a hydraulic conductivity of no more than 1 x 10-8 m/sec. Above-ground berms must be made of material that can be compacted with a saturated hydraulic conductivity of no more than 1 x 10-9 at 95% of modified Proctor density according to accepted engineering test criteria.
Some construction details for earthen facilities are presented in section 65 and 79 of the Regulation.
Liners - Earthen facilities must also include a liner, unless they are for the storage of liquid agricultural source material other than manure, and do not exceed the maximum capacity and dimensions shown in Figure 2.
Synthetic liners are defined in the Regulation as a geomembrane liner or a geosynthetic clay liner. Geomembrane liner is a synthetic membrane with very low permeability, whereas a geosynthetic clay liner is a liner that consists of high swelling sodium bentonite between two layers of geotextile fabric having a saturated hydraulic conductivity of 1 x 10-9 m/sec or less. Both types of synthetic liner are used to control fluid migration in a nutrient storage facility. Section 74 of the Regulation provides more details about the installation of synthetic liners.
Compacted soil liners are defined in the Regulation as a liner that is composed of hydraulically secure soil that is compacted to 95% of modified Proctor density at the optimum moisture content to meet a maximum saturated hydraulic conductivity of not more than 1 x 10-9 m/sec.
Liner details are presented in sections 73 to 75 of the Regulation. Section 75 of the Regulation specifies how to construct a compacted soil liner. For example, it must be constructed:
Secondary containment - If the liquid level in the storage facility is partially or wholly above the surface of the surrounding soil, the following options apply:
Ventilation - All covered storage systems must have a ventilation system that is either a powered or natural ventilation system to prevent the accumulation of corrosive or noxious gases.
A nutrient storage facility often includes a liquid nutrient transfer system. A transfer system includes the sump pit, pump and associated piping to move manure from a barn to a storage facility. This system can also be used to transfer other agricultural source material (e.g., washwater, runoff) or NASM. All liquid transfer systems, other than floor transfer systems as defined in the Regulation, must be designed by a professional engineer.
Transfer systems rely on gravity or mechanical devices (e.g., pumps and piping) to move the material. Regardless of the conduit used, it is important to make secure connections.
Rubber gaskets and bell and spigot connections are commonly used to make sure that the transfer piping is watertight. Proper connectors ensure that the integrity of the system is maintained. Figure 4 shows a PVC transfer piping system being assembled during barn construction.
The Regulation states that no person shall construct or expand a liquid nutrient transfer system when constructing a permanent liquid nutrient storage facility unless:
All connections in a liquid transfer system must be installed using specifically designed fittings and gaskets that are compatible with the pipe material. (See O. Reg. 267/03, s. 87):
For more information on transfer systems, see the OMAFRA Factsheet, Nutrient Management Act, 2002 - On-Farm Liquid Nutrient Transfer Systems, and the Regulation.
The Regulation specifies minimum site conditions and construction standards, but consider the following items in the design and construction of a liquid nutrient storage facility made of earth:
Contact the local municipality to verify if additional requirements apply to your project.
Think about features such as an agitation pad or tractor access ramps. These systems should be properly incorporated into the earthen storage to ensure safety, structural integrity and leakproof construction. Features judged to be a structure require building permits. Features such as a tractor access ramp can add a large surface area, increasing rainfall amounts that must be stored and land applied.
See these OMAFRA Factsheets for more information:
For the applicable requirements under the NMA for a facility or any component of a facility that is constructed of concrete or steel, see the OMAFRA Factsheet:
This Factsheet was originally written by Don Hilborn, P.Eng., OMAFRA, Woodstock, and John Johnson, P.Eng., (retired), OMAFRA, London. It was revised by Benoit Lebeau, P.Eng., OMAFRA, Kemptville, and Richard Brunke, P.Eng., OMAFRA, London.
Nutrient Management Disclaimer 2018
The information in this factsheet is provided for informational purposes only and should not be relied upon to determine legal obligations. To determine your legal obligations, consult the relevant law, www.e-laws.gov.on.ca. If legal advice is required, consult a lawyer. In the event of a conflict between the information in this factsheet and any applicable law, the law prevails.
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