Industrial by-products

Yellow tank truck spraying dark liquid on grassy fieldAn industrial by-product (IBP) is a residual material from an industrial, commercial, mining, or agricultural operation that is not a primary product and not produced separately in the process. IBPs that originate from food, beverage, and agricultural operations are regulated through industrial water-quality permitting. Examples include:

  • Vegetable, dairy, and meat processing wastes
  • Solids/residuals from the pretreatment of wastewater
  • Ethanol production wastes and co-products
  • Livestock truckwash solids and washwater

NOTE: Biosolids generated from the treatment of municipal wastewater are regulated separately from IBPs in Minnesota. See the biosolids page for more information. In addition, egg shells, beet solids, lime residuals, wood ash, and some other IBPs are regulated separately for reuse. See the Beneficial use of solid waste page for more information.

Minnesota rules define IBPs as solid waste, but IBPs from food, beverage, and agricultural operations typically contain nitrogen, potassium, phosphorus, and other nutrients and are good candidates for land application. Reusing nutrients by land applying IBP reduces the use of water and commercial fertilizer and replenishes the soil. The nutrients in IBPs mean their storage and land application can affect the environment. IBP can become harmful if too much is applied and excess nutrients run off into nearby lakes and streams, and affect groundwater. People applying IBP to land must follow best management practices and permit requirements, such as using proper application rates and monitoring soil and runoff, to protect water from contamination.

The guidelines and general permit below detail the management standards, including when a permit is required and mandated sampling and analysis, for most IBPs suitable for land application.

Do I need a permit?

Typically, a permit is required for: 

  • Land application of more than 50,000 gallons or 10 dry tons of IBP per year
  • IBP storage at a volume that could create environmental concerns

PDF icon Figure 1. Permit Decision Flow Diagram for Land Application of Industrial By-product -- shows the decision process for determining whether a permit is required, and what type of permit would likely be issued.

Some IBP-related activities don't require an MPCA permit. For example, you don't require an SDS permit if the IBP is:

  • Used for fuel or animal feed
  • Managed at a solid waste facility
  • Managed under the Solid Waste Utilization rules (Minn. R. 7035)
  • Land applied in very small quantities, in accordance with best management practices
  • Generated by small-scale crop producers and managed on-site

Contact the MPCA to discuss whether a permit is needed for your IBP activities. Find permit forms and information about applying here.

Sampling and analysis requirements

Before land applying an IBP or submitting a permit application, you must collect and analyze a representative portion of IBP for the nine analytes listed below, on a dry weight basis. However, sweet corn silage doesn't require analysis, and if there's no oil and grease in a waste stream, that analysis is not necessary.

  • Chloride
  • Nitrogen, Ammonia
  • Nitrogen, Kjeldahl
  • pH, Sludge
  • Phosphorus
  • Sodium
  • Solids, Total
  • Solids, Total Volatile
  • Oil and grease, Total Recoverable

Analyze IBP for all pollutants with a "reasonable likelihood" of being present, based on your knowledge of the waste generation process. MPCA staff may also request additional analysis when you submit a notification or permit application. If it's possible that your IBP contains polychlorinated biphenyls (PCBs) or dioxin/furan compounds, these must also be analyzed for and the test results discussed with the MPCA. The IBP is also subject to ongoing monitoring; the number of samples is determined by IBP generated and land applied during a cropping year.

General permit

The general permit can usually cover land application of IBPs from food, beverage, and agricultural industries. IBPs not covered by the general permit include:

  • Hazardous waste
  • Egg shells
  • Sugar processing residues
  • Animal wastes regulated under feedlot rules (Minn. Rule 7020)
  • Dead animals
  • Residue from drinking-water treatment or industrial process-water conditioning.

If the IBP did not come from a food, beverage, or agricultural process and may contain minerals, metals, or other contiminants of concern, additional waste stream analysis is necessary and loading restrictions must be followed as outlined in PDF icon Guidelines for Managing Industrial By-Products from Food and Beverage Processing Industries (wq-lndapp2-03)

Individual permit

The MPCA may require an individual permit if an IBP is not from a food, beverage or agricultural process. Submit permit application forms at least 180 days before land application will begin. Find permit forms and information about applying here.

Annual reporting

Use the annual reporting form to report land application activities.

Land application not requiring a permit

If an IBP is eligible for a general permit and less than 50,000 gallons or 10 dry tons per year will be land applied, a permit may not be necessary. Complete a Microsoft Office document icon Notification to Land Apply Industrial By-Product Without a PermitMicrosoft Office document icon for land application projects that don't require an MPCA permit and that the Solid Waste Utilization program doesn't cover. Submit the form at least 30 days before starting land application. If the MPCA concurs that a permit is not required, it will not send a formal response; land application activity can commence at the end of the 30 days. If the agency determines that a permit is required, it will notify you with the 30 days. Land application may not begin until the discrepancy has been resolved and a permit issued for the project, if required. You must follow best management practices for IBP land application. Allowing the storage of IBP without a permit is rare.

Land application site management

Site selection and use

Regardless of whether you need a permit, you must evaluate proposed land application sites to ensure they have appropriate characteristics and the soils can use the IBP nutrients. Soil suitability can be determined with Natural Resources Conservation Service soil surveys, or characterization by a state-licensed soil scientist or Type IV certified land applicator.

Soil testing

Soil sampling is required both before the site is used for the first time, and once every three years while a site is used. Sites used for IBP land application must be sampled and analyzed for six analytes:

  • Texture (USDA class)
  • Organic matter
  • Phosphorus, extractable in soil
  • Potassium, exchangeable in soil
  • pH (SU)
  • Salts, water soluble in soil

One composite soil sample is required for each land application site, unless the site is larger than 40 acres. In that case, one sample is required for each 40 acres or portion thereof. For example, a 60-acre site would require two soil samples; a 220-acre site would require six soil samples.

Site notification

For permitted land application, you must submit an Microsoft Office document icon Industrial By-Product Site Notification form (wq-lndapp7-11) at least 30 days before applying IBP at the site. Site notification is not necessary if a permit is not required. Sites must meet all the selection and use criteria outlined in the guidance and/or land application permit.

Local notification

You must notify local officials -- either county planning and zoning or solid waste staff, township clerk, or mayor -- in writing at least 30 days before IBP land application begins. In the notification, describe how IBP will be managed during land application, including staging, storage and response actions in the event of a spill. If the IBP management described in the notification changes, you must repeat the notification process.

End-user notification

No later than six weeks after land application, you must provide the end user -- the site's owner -- with written information to ensure that a site is not receiving too many nutrients. This would include nutrient application rates, any restrictions on IBP use, crop restrictions, etc.

Type IV certified operator

A Type IV-certified land applicator must perform land application that requires a permit. If a permit is not required, the MPCA doesn't require a certified applicator. See the Wastewater operators' training and certification page.

Loading limitations

Accurately calculating how much IBP to apply to a particular site is critical. Over-application of nitrogen, sodium, metals, and other pollutants can harm the environment. You must account for all sources of nitrogen when determining how to meet application limits. Learn more on the Biosolids page. To calculate the maximum allowable rate of the IBP to meet the nitrogen and sodium limits, use one of the electronic application rate calculators below: 

To calculate the amount of nutrient loading based on the rate of IBP applied, use one of the electronic actual rate calculators below:

IBP storage

Storage of IBP without a permit for land application activities is very limited. The following types of storage are allowed, if a permit is not needed for land application:

  • Temporary storage at the land application site
  • Transfer to manure storage structure
  • Storage of sweet corn silage used for animal feed

Dewatered IBPs that are being spread concurrent with the unloading of bulk material on the land application site, and will not be stockpiled overnight, are not considered IBP storage. Other IBP storage is not allowed without an MPCA permit, even if a permit would not otherwise be required for land application.

Temporary storage

Storage of dewatered IBP is allowed if:

  • Storage does not exceed 30 days
  • Storage is only on the site were the IBP will be applied, and the quantity does not exceed what can be applied at that site
  • Storage is not on land with a more than 2% slope, unless water runon and runoff from the stockpile and/or site are controlled

Transfer to manure storage structures

Before using a manure storage structure to store IBP, you must get written authorization from the MPCA and the county feedlot officer in delegated counties, or the county solid waste official in non-delegated counties, using the application form below.

Storage of sweet-corn silage

Vegetable processing plants make sweet-corn silage available to farmers for use as animal feed. It produces a very acidic waste fluid with a high nutrient content, and must be stored in a way to protect the environment. Anyone storing more than 1,000 tons of fresh sweet-corn silage must obtain an MPCA permit.

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