Land application of industrial by-products

This webpage and documents contained on it are intended for use by persons or operations that generate industrial by-product (IBP) suitable for land application to help them determine what type(s) of regulatory oversight and/or permit is required for proposed activities, including land application, storage, and transfer to other facilities. Land application of biosolids, lime residuals, and wood ash are regulated separately from other IBPs and are not the focus of this website.

General information

An industrial by-product (IBP) is a residual material resulting from industrial, commercial, mining, and agricultural operations that are not primary products and are not produced separately in the process.

IBP is technically classified as solid waste under Minnesota Rules, and are the result of processes such as food and beverage processing, livestock vehicle washing, ethanol production, generation of electricity, and treatment of drinking water. Examples of IBP’s from these industries include:

  • Vegetable processing wastes, such as sweet corn silage/leachate and production wastewater
  • Dairy processing wastes, such as whey, separator solids, dryer rinsate and condensate
  • Meat processing wastes, such as cleanup water
  • Solids/residuals from the pretreatment of wastewater
  • Wood, coal, and mixed ashes
  • By-product limes
  • Ethanol production wastes and co-products, such as thin stillage and process condensate
  • Livestock truckwash solids and washwater

Note: Biosolids generated from the treatment of municipal wastewater is not an IBP and is regulated separately from IBP’s by state rule. Regulation and management requirements for biosolids are not addressed on this Web page. In addition, management of lime residuals and wood ash are regulated separately from other IBPs and are not addressed on this Web page. Refer to MPCA pages on Solid Waste Utilization and Wastewater for more information on these topics.

In addition to other reuse and management options, IBP from food, beverage and agro-industrial operations are good candidates to be managed via land application. IBP from food, beverage and agro-industrial processing operations, which is the subject of this Web site, typically contains nutrients such as nitrogen, potassium and phosphorus - the same nutrients found in commercially produced fertilizers. Reusing nutrients in the IBP by applying it to the land, as opposed to using a disposal method, is not only a sound and generally accepted business practice; it is a sound and generally accepted agricultural practice. Reusing nutrients by applying nutrient-containing IBP to the land saves water resources, reduces the amount of commercial fertilizer that would otherwise be purchased and applied to agricultural land, and replenishes the soil with nutrients that are taken up by plants and removed in the farming process.

Environmental considerations

Land application activities, as well as the management structures and areas for the storage IBP prior to land application, have the potential to impact the environment. Storm water runoff from management site(s) has the potential to pollute surface water when discharged to waters of the state. The management of IBP also has the potential to affect ground water through on-land management methods, if not managed in consideration of environmental risk factors. Surface water discharges, though not common, can also occur, such as from tile line outlets, and can be a source of pollution, if not managed appropriately.

The same nutrients that are beneficial to plants and soil can become pollutants if not applied properly, or if too much is applied. Application of nutrients to agricultural areas, either in the form of conventional fertilizers or by the reuse of nutrients from wastewaters, must be done in accordance with scientifically established agronomic rates to avoid contamination of ground and/or surface waters from these nutrients washing off the land (to surface water) or through the soil profile (to ground water).

Limitation of the application rate and monitoring of soil and runoff is a proven way to ensure that the crops and the land are using the nutrients that are applied, thus avoiding contamination. This is done via the utilization of best management practices (BMPs), either in the context of permit conditions, or the application of guidelines for activities not requiring a permit.

Additional information

The guidelines and general permit for land application of industrial by-product from food, beverage and agro-industrial processing facilities (MNG960000) referenced on this Web page detail the management standards for most industrial by-products that are suitable for land application. The documents contain all the specific information you will need to determine what sampling and analysis is required, whether a permit is required and how the IBP must be managed (technical specifications regarding the selection and use of land application sites, as well as storage and transfer standards).

A synopsis of this information is contained in the following document, which has been prepared for use in situations where a permit is not required.

MPCA land application staff are available to consult on specific proposals.

Sampling and analysis of IBP

Before land applying an industrial by-product (IBP), representative samples of each IBP intended to be land applied must be sampled to determine the level of nutrients and other pollutants present. Each waste stream produced and land applied must be sampled and analyzed for at least the 9 analytes listed below, on a dry weight basis, with two exceptions. First, sweet corn silage does not need to be analyzed (at all). Second, if a waste stream does not have oil and grease in it, this analyte may be excluded from analysis.

The 9 waste stream analytes are:

  • Chloride (as Cl) (mg/kg);
  • Nitrogen, Ammonia, (%);
  • Nitrogen, Kjeldahl, Total, (%);
  • pH, Sludge (SU);
  • Phosphorus, Total (%);
  • Sodium (as Na) (mg/kg);
  • Solids, Total (%);
  • Solids, Total Volatile (%); and,
  • Oil and Grease, Total Recoverable (mg/kg)

These analytes most commonly limit the amount of IBP allowed for land application. To ensure that representative sampling is done, all pollutants with the ‘reasonable likelihood’ of being present should be analyzed for. To determine whether a particular pollutant has a reasonable likelihood, use your knowledge of the waste and waste generation process, as well as in consultation with MPCA staff; MPCA may also request additional analysis when the Notification or Permit Application is submitted. If there is a possibility 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.

In addition to this initial characterization of the IBP, the IBP is monitored on an on-going basis, with the number of samples required to be analyzed determined by the amount of IBP generated and land applied during a cropping year. On-going monitoring is specified either by Table 2 of the general permit, or specified in the Limits and Monitoring section of an individual permit.

Do I need a permit?

Typically, a permit is required for land application of more than 50,000 gallons or 10 dry tons of industrial by-product per year, or if there is storage of industrial by-product at a volume that could create environmental concerns. Figure 1 below, describes the decision process for determining whether a permit is required, and what type of permit would likely be issued. Depending on the length and method of storage, storage standards will vary. To determine whether a permit is required for storage, refer to Figure 2 in the guidelines document or consult with MPCA staff.

PDF icon Figure 1. Permit Decision Flow Diagram for Land Application of Industrial By-product

Some scenarios for the management of industrial by-product do not require a permit from the MPCA. For example, if an IBP is used for its intended purpose, used for animal feed, used for fuel in accordance with applicable standards, or managed at a solid waste facility in accordance with applicable standards, an additional SDS permit for the generator of the waste is not required.

In addition, an IBP managed under the Solid Waste Utilization rules (Minn. R. 7035), or de minimus quantities of IBP that are land applied in accordance with Best Management Practices (BMPs) -- so as not to represent an environmental concern, are also not required to obtain an SDS permit for the activity.

More information on the solid waste utilization rules can be found on the Solid Waste Utilization page.

For land application activities requiring a permit

For land application activities requiring either an individual or general permit, the appropriate management requirements will be placed into the permit, which depend of the specifics of the waste generated and proposed activities. General permit number MNG960000 is in place to authorize the land application of industrial by-products generated by food, beverage, and agro-industrial processors, as well as the storage of IBP prior to land application.

Land application of a specific IBP may be appropriately covered by general permit number MNG960000 if the following conditions are true:

  • The industrial by-product is not a hazardous waste.
  • The concentration of the analytes listed in Table 2, below, are not exceeded in the industrial by-product.
  • Annual application rates of the industrial by-product does not cause the limits for the analytes specified in Table 3, below, to be exceeded.
  • The industrial by-product is not egg shells, IBP from the processing of sugar, animal manures or paunch manures, regulated under feedlot rules (Minn. Rule 7020), dead animals or residuals from the treatment of drinking water or conditioning of industrial process water. Refer to the Solid Waste Utilization page or the Wastewater page for additional information on these topics.

Table 2. Concentration limits for industrial by-products on a dry weight basis.



Total Arsenic

41 mg/kg

Total Cadmium

39 mg/kg

Total Copper

1500 mg/kg

Total Lead

300 mg/kg

Total Mercury

5 mg/kg

Total Molybdenum

75 mg/kg

Total Nickel

420 mg/kg

Total Selenium

100 mg/kg

Total Zinc

2800 mg/kg

Total Dioxin equivalents

10 parts per trillion

Total Polychlorinated biphenyls

6 mg/kg

Table 3. Annual application rate limits.




170 lb/acre/yr


1.8 lb/acre/yr


1.7 lb/acre/yr


67.0 lb/acre/yr


13.0 lb/acre/yr


0.76 lb/acre/yr


19.0 lb/acre/yr


4.5 lb/acre/yr


125.0 lb/acre/yr

An individual permit is developed for a specific project or site activity, with specific process wastewater, discharge location(s) and situation in mind. For example, land application of an industrial by-product that is not from a food, beverage or agro-industrial  producing operation would require individual permit coverage, such that any potential pollutants are adequately considered.

As a result, an individual permit is unique to specific land application activities and will provide specific terms and conditions that must be met to be protective of the environment. The permit application forms should be submitted at least 180 days prior to the anticipated initiation of land application activities.

If either an individual permit or general permit coverage is required for your activity, complete and submit the following permit application forms for MPCA review.

For Land Application Activities NOT Requiring a Permit

A Notification to Land Apply Industrial By-Product without a Permit (Notification) must be completed and submitted for all land application projects not requiring an MPCA permit, and which are not covered by the Solid Waste Utilization program. A Notification form must be submitted at least 30 days prior to the initiation of land application activities. In some cases, MPCA staff may be able to reduce the amount of time needed for MPCA review.

Within this 30 day timeframe, MPCA staff will review the Notification and either concur with the determination, or determine that a permit or additional information, such as additional sampling or monitoring, is required. If the MPCA concurs with your determination that a permit is not required, a formal response will not be sent; land application activity can commence at the end of the 30 day time period. If, after review of the Notification submitted, the Agency does not concur with your determination that a permit is not required for the project, the Agency will notify you of this determination within the 30 day time period. Land application activity may not commence until the discrepancy has been resolved and a permit issued for the project, if required.

In addition to submitting notification, Best Management Practices (BMPs) for the land application of industrial by-product must be followed in order to qualify for a de minimus exclusion from the requirement to obtain a permit. Storage of IBP without a permit is very limited.

Management standards

Site selection and use

Before a site can be used for the first time, the suitability of a proposed site must be determined to ensure that the soils are able to utilize the nutrients in the industrial by-product, and that the geography of the site is amenable to land application. This is required whether or not a permit must be obtained.

The following site characteristics are addressed by requirements in either the general land application permit, an individual permit, or by the Best Management Practices (BMPs) required for activities without a permit. Additional requirements apply to the land application of IBP containing pathogens.

  • Soil texture
  • Slope and depth to water table
  • Separation distances
  • Crop restrictions/public access

Soil suitability information can be determined by obtaining information from soil surveys published by the Natural Resources Conservation Service, or by characterization of the site by a state of Minnesota licensed soil scientist or other qualified person, such as a Type IV certified land applicator.

Refer to the guidance document and/or the general permit language for specific requirements for site selection and use.

Soil testing

Soil sampling is required both before the site is used for the first time, and once every 3 years a site is used. If a site is not used during a cropping year, there is no need to sample the soil. Each land application site used for land application of industrial by-product must be sampled and analyzed for at least 6 analytes:

  • Texture (USDA class);
  • Organic Matter (%);
  • Phosphorus, Extractable in Soil (ppm);
  • Potassium, Exchangeable in Soil (ppm);
  • pH (SU); and,
  • Salts, Water Soluble in Soil (mmhos/cm).

Note: only one type of soil phosphorus analysis is required, based on the pH of the soil at the land application site.

One composite soil sample is required for each land application site, except if the site is larger than 40 acres. If the site is larger than 40 acres in size, one sample is required for each 40 acres or portion thereof. That is, a 60 acre site would require 2 soil samples; a 220 acre site would require 6 soil samples.

MPCA notification

For land application activities requiring a permit, you must submit a Site Notification Form at least 30 days prior to application of IBP at a particular site. If a permit is not required for land application activities, the MPCA does not require site notification of sites that will be used for land application of IBP. Although the sites are not approved by the MPCA, the sites must meet all the site selection and use criteria outlined in the guidance and/or land application permit, as applicable and still complete the local notification requirement (described below).

To notify the MPCA of sites to be used for land application, use the Site Notification form:

Local notification

Before land application activities are initiated within a county, city or township for the first time, written notification to local officials -- which includes either the county Planning and Zoning or Solid Waste officer (whichever is appropriate), and either the township clerk or mayor (depending on location of the site) - must be done. The local notification process gives the local jurisdiction the opportunity to ask questions and request more information about the land application program at a Facility (copies of records, testing information, individual site information, etc.), and/or provide information to the generator of the waste, applicator(s) and land owner(s) of any local requirements. Local notification must be provided at least 30 days before initiating land application activities.

Notifications must contain a description of how the IBP will be managed during land application, which includes staging, storage and response actions in the event of a spill, and a response section for the local official. If any changes in the management of the IBP described in the notification occur, the notification process must be repeated.

To notify local authorities of land application activities, you can use one of the following sample letters as a template:

End user notification

For each site used for land application of an IBP, the end user - if other than yourself — must be provided with the information necessary to ensure that - collectively, from all nutrient sources — a site is not receiving too many nutrients. An “end user” is the person that has accepted the IBP for their use as a soil amendment — usually a farmer.

Information the end user will need includes information such as actual nutrient application rates, any restrictions on the IBP use, crop restrictions, etc. The end user must be provided with this information in writing as soon as possible, and in no case more than 6 weeks after application has been completed. End users should take appropriate credits for all plant nutrients supplied by industrial and municipal by-products, manures, and fertilizers so that maximum allowable application rates are not exceeded.

Type IV certified operator

Land application activities requiring a permit must be done by or under the supervision of a Type IV certified land applicator. If a permit is not required for land application activities, the MPCA recommends, but does not require, the land application be done by or under the supervision of a Type IV certified operator. See the training for wastewater operators webpage. 


Loading limitations

The effects of IBP on crops and the environment rely on the ability of the manager of land application activities to accurately calculate the amount of IBP to apply to a particular parcel of land. Inaccurate calculations can lead to the over-application of nitrogen, sodium, metals and other pollutants which can harm the environment. Incorrect calculations can also result in the under-application of these components, which result in a lower-than-expected crop yield.

The table below provides a summary of loading limitations for the application of industrial by-product.

Table 4. Summary of application rate limits.

Loading Factor



Varies - MANA (lb/acre/year)


170 lb/acre/year

Daily Hydraulic Rate1:
Soil Texture Fine
Soil Texture Medium
Soil Texture Coarse

10,000 gal/acre/day
15,000 gal/acre/day
25,000 gal/acre/day

Winter Hydraulic Rate

15,000 gal/acre/winter

1 Fine, medium, and coarse textured soils are defined by the Department of Agriculture (USDA) textural classifications as [clay loam, silty clay loam, sandy clay, silty clay]; [loam, silt, silt loam, and sandy clay loam]; and [sand, loamy sand, and sandy loam], respectively.

For a detailed explanation of how to calculate loadings for land application, refer to Chapter 12 of the MPCA document, “Land Application of Biosolids: A Manual for Minnesota (2001).”

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:

General Provisions for Land Application

There are some additional general provisions that must be followed when land applying IBP to prevent nutrients from washing off the land (to surface water) or through the soil profile (to ground water), thereby avoiding contamination of ground and/or surface waters. Refer to the guidance document, the general permit language, and/or your individual permit for these specific requirements.

Storage of industrial by-product

Storage of industrial by-product 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 activities:

  • Temporary storage at the land application site.
  • Transfer to Manure Storage Structure.
  • Storage of sweet corn silage used for animal feed.

For the purposes of this guidance, dewatered industrial by-products 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 storage of an industrial by-product. The term “dewatered” is defined in the glossary of this guidance document, as well as the general permit.

Other storage of industrial by-product is not allowed without a permit from the MPCA, even if a permit would not otherwise be required for land application activities. Contact MPCA staff for additional details.

Temporary storage

Storage of industrial by-product that is dewatered is allowed under the following conditions:

  • Storage must not exceed 30 days.
  • Storage shall only occur on the land application site where the industrial by-product will be applied.
  • The quantity of industrial by-product to be stored at an application site shall not exceed the quantity of material that can be applied to that site.
  • Short-term storage shall not take place on land with a slope greater than two percent unless measures are taken to control water runon and runoff from the stockpile and/or site.

Transfer to manure storage structures

Prior to use of a manure storage structure for the storage of industrial by-product, written authorization from the county feedlot officer in delegated counties, or the county solid waste official in non-delegated counties, as well as the MPCA, must be obtained.

To seek approval to use a manure storage structure for storage of an industrial by-product, complete the Transfer to Manure Storage form below and submit it to the county feedlot officer in delegated counties, or the county solid waste official in non-delegated counties. Once the form is signed by the county official, the completed form should be mailed to the MPCA.

Storage of sweet-corn silage

Sweet-corn silage is made available by vegetable processing plants to farmers for use as animal feed. Like field-corn silage, it is a valuable feed product; however unlike field-corn silage, it produces much more silage juice because it is harvested at a higher moisture content.

Sweet-corn silage produces silage juice, which is a very acidic waste with a high nutrient content (high strength). Silage must be stored in a manner to be protective of the environment. Anyone that stores more than 1,000 tons of fresh sweet-corn silage on site at any one time is required to obtain an MPCA permit.

Land application forms

For Land Application Activities Requiring a Permit

Apply for permit coverage using the following forms:

To notify the MPCA of sites to be used for land application, use the Site Notification form:

To notify local authorities of land application activities, you can use the following letter as a template:

To report land application activities, use the Annual Reporting Form:

To seek approval to transfer IBP to a manure storage structure, complete and submit the following form:

For Land Application Activities NOT Requiring a Permit

For land application activities not requiring a permit, complete and submit the Notification form:

To notify local authorities of land application activities, you can use the following letter as a template:

General Permit information

General Permit Reissuance

The MPCA has recently reissued the general permit for land application of industrial by-product from food and beverage processing facilities (MNG960000). The currently effective general permit MNG960000 expires on November 30, 2018.

Who to call

MPCA land application staff are available to consult on specific proposals. For general information about content on this Web page, contact Emily Schnick, 651-757-2699.

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