How to achieve the best temporary solid storage solution.
May 23, 2023 by James Careless
There are several ways to store solid manure – and sometimes, your method of storage depends on how long you intend to store it. This being said, different jurisdictions have different rules on how long one can keep solid manure in at a temporary storage site before it is required to be in long-term storage.
With the summer growing season coming up, temporary manure storage can be a good solution for farmers, allowing them to clean out pens and store the manure until there is an appropriate window for application during or after the growing season.
Temporary solid storage can be a helpful tool – but there are region-specific guidelines to keep in mind in different states and provinces. While this report has examples of details on B.C. and Alberta guidelines, it is always best to check the specifications in your jurisdiction.
Why temporary storage needs to be truly temporary
In the old days, many farmers would simply let solid manure build up in their pens for months, even years, without worry. However, based on what we know now, this isn’t an environmentally safe practice.
“Concerns begin to arise should farmers site temporary storages under conditions that could cause nutrients to migrate away from the pile,” says Jake Turek, waste management engineer with the British Columbia Ministry of Agriculture and Food. “Examples of irresponsible siting could include stockpiling manure on coarse soils where nutrients could reach aquifers or in a low spot where runoff and precipitation would pool.”
As well, temporary manure storages that lack proper site preparation can contaminate groundwater, and cause “significant nutrient deposition at a site,” says Deanne Madsen, sustainable agriculture resource specialist with Alberta’s department of agriculture and irrigation.
“This is made worse if there are no management or cropping options available to remove nutrients from the site.” Add the risk of odors, flies and aggravation to neighbors, and temporary manure storages need to be just that – temporary.
Rules may vary
Before depositing manure at temporary storage sites, farmers should check the rules in their jurisdiction. For instance, the Code of Practice for Agricultural Environmental Management governs temporary field storage of solid manure in British Columbia. “In high-precipitation regions (areas that receive 600mm or more of precipitation from October 1 to April 30), the temporary field storage must be covered from October 1 to April 1,” says Turek. “Additionally, in regions that are classified as vulnerable aquifer recharge areas, the pile must not be located over coarse soils. If the temporary field stored manure is located in the same spot for two weeks or more, that site must not be used for another three years.”
In Alberta, temporary manure piles are referred to as “short-term solid manure storages” in the Standards and Administration Regulation under the Agricultural Operation Practices Act (AOPA). “AOPA allows owners or operators to store solid manure, at a short-term storage site, for only a total of seven months over a three-year period,” says Madsen. “They are also required to locate sites at least 100 meters (about 328 feet) away from a water well or spring, place them one metre above the water table and one metre above the one in 25-year maximum flood level, with a 150 meter setback from the nearest neighboring residence.” Temporary manure storages must also be at least 30 meters from a common body of water when the land slopes toward that water body with a slope of four percent or less, 60 meters away for a four percent to six percent slope, and 90 meters away for less than a 12 percent slope. “Any steep land that slopes more than 12 percent towards a common body of water must not be used to store manure,” she says.
Finding the best site
To put the above limits and rules into a positive light, the best sites for temporary manure storages are high and dry, on top of “fine soils to minimize the escape of leachate and cover during periods of high precipitation to minimize leachate production,” says Turek.
“Sites should be located away from places where water pools or runs off the property into water bodies,” Madsen adds. Ideally, any runoff should be retained in the field, which should remain flood-free and accessible even during wet weather.
If the site meets this criteria and the applicable rules governing temporary manure piles, then no site preparation should be necessary. But be prepared to restore the site’s vegetation (if so required) once the manure has been moved, and save yourself grief by locating this storage as far from neighbours and roadside traffic as possible. People are unlikely to complain about what they don’t see or smell.
Remember: Temporary is temporary
Farmers should assume their jurisdiction has time limits for temporary manure storages, and be prepared to stay within them to avoid legal problems and fines.
In Alberta, if an owner or operator of a site exceeds a total of seven months in a three-year period, they could be subject to compliance action by the Natural Resources Conservation Board (NRCB). “The NRCB will work with producers to find an acceptable solution,” says Madsen. “This can include spreading, moving it to another temporary storage site, or applying for a permit for long-term manure storage.”
The same limit applies in B.C. “Farmers must move the temporary storage pile after seven months to permanent storage where agricultural by-products can be stored for longer periods of time, and apply if possible, or export off-farm,” says Turek. “Seven months is the maximum duration for temporarily storing material, but that does not mean storing material for the maximum amount of time is a ‘best’ or beneficial management practice.”
Given the reality of such time limits, Madsen’s words of advice on temporary storage are worth heeding. “Plan ahead. Identify suitable sites ahead of time. Remember that while short-term manure storage sites are very effective tools, a site is limited to seven months out of a three-year period — so time their use appropriately.” •