Skip to main content

Rock crushing

The rock crushing or aggregate producing industry has a range of environmental regulations that impact their operations. The following links provide some basic information on those requirements.

Air pollution regulations

Nonmetallic mineral mining/crushing operations must apply for an air pollution permit and properly manage fugitive dust emissions. The following documents cover the emissions calculations and permitting requirements:

Example recordkeeping documents were created by the Small Business Environmental Assistance Program (SBEAP) for those plants who request help on those requirements:

Fugitive dust control

"Fugitive dust" is a term used to describe any particulate matter (PM) emissions released through any means other than a stack or duct of some kind. Any business creating enough dust, smoke, or fumes to be a noticeable source of air pollution must control those emissions. The following are examples of activities that would create fugitive dust:

  • large trucks transporting materials along unpaved roads;
  • unpaved parking lots;
  • piles of materials stored on site, like grain; and
  • dry materials directed to equipment not collected by another device, whether by baghouse, cyclone, wet scrubber, etc.

Any business that creates fugitive dust must do as much as possible to control those emissions and keep them from escaping into the environment. The following are a few suggestions based on the type of activity. Other best management practices recommended by industry experts are provided in the fact sheet Fugitive Dust Management (AM-556).

Submitting Reports to Air Management Program

The following are reports, certifications or notifications required for GOP sources:

  • January 30th - Annual Summary of Monitoring and Annual Certification of Compliance is due
  • March 1st - Air emissions inventory reporting is due; certification now happens upon submittal
  • As needed
    • Next Day Deviation Report
    • Relocation Notification

Electronic reporting access

All reports listed above can be submitted electronically. Online reporting options streamline the process through use of the DNR Switchboard and Air Reporting System. The electronic signature for reports is only available to the facility's responsible official.

  • The facility's responsible official, air management contact and/or delegated party must obtain a Web Access Management System (WAMS) ID to access the DNR Switchboard.
  • Next, facility contacts need to request access to the compliance and air emission inventory roles in order to file reports electronically.
  • Learn about all electronic submittal options at: Air Compliance Submittal Actions Electronic Reporting.
  • Tutorials on different steps in the electronic submittal process are available as well: Tutorials.

Annual summary of monitoring and certification of compliance – due January 30

Facilities covered by a GOP must submit an annual summary of monitoring and a compliance certification to DNR for each calendar year’s operations. These reports shall include enough information to determine the compliance status of the source with each applicable permit condition.

  • DNR developed a Combined Annual Monitoring Report and Certification of Compliance form for facilities covered by a GOP. Use of form 4530-177 is not mandatory, however, any report submitted by the facility must contain the same information as the form.
  • The report can be submitted and signed electronically. If the facility uses their own format, all documents should be combined and submitted as a single report.
  • The responsible official is required to certify whether compliance was continuous or intermittent for each condition.

Air Emissions Inventory – due March 1

All facilities covered by a GOP must submit an annual Air Emissions Inventory (AEI) report if they are above the reporting thresholds in ch. NR 438, Wis. Adm. Code:

  • All emission units shall be included in the AEI, including insignificant units and fugitive dust emissions.
  • If you need an extension, submit the request through the Air Reporting System (ARS) and NOT by email.
  • Businesses with air emissions below the reporting thresholds listed on Table 1 of Chapter NR 438, can submit an Under Threshold Notification (UTN) to notify DNR their air emissions are below reporting levels. The UTN is generated and submitted electronically within the Air Reporting System (ARS).

For help with submitting the AEI or UTN review the Tutorials webpage. For direct assistance, contact DNRAMEmissionsInventory@wisconsin.gov.

Air Emissions Inventory Certification

Facilities submitting an annual Air Emissions Inventory (AEI) report must certify the report after completing the QA review of the data. This will occur upon submittal of the report.

  • New in 2023 is that the responsible official must sign the AEI certification.
  • Learn how to complete the final report certification for the AEI in AM624.
  • This certification is not required for facilities completing the Under Threshold Notification (UTN) or facilities that completed the AEI but had emissions below reporting levels in NR 438.

Deviations from requirements

Facilities are required (s. NR 439.03(4), Wis. Adm. Code) to report any deviation from permit requirements by the next business day. Deviations may include certain malfunctions or other unscheduled events (e.g., accidental release of pollutants) at the source that were not reported in advance. Review DNR’s guidance memo on how deviations must be reported.

Relocation Notification

Portable sources are required to notify the department at least 20 days prior to each relocation. The written notice should be uploaded to the DNR Switchboard following these steps:

  1. Complete Form 4500-025 or complete a similar notice and save in Portable Document Format (PDF).
  2. Login to Switchboard, select your facility and then select "Air Compliance Actions."
  3. Under the "Other Reports, Plans, and Notifications", select "Upload New Document."
  4. Choose "Notification" and then “Portable Source Relocation Notification” from the drop-down menus.
  5. Indicate the County where the portable source will be relocated.
  6. Browse for the relocation notification file (PDF only) on your computer and then select "Upload Document."

Alternatively, you can send relocation notifications directly to the assigned air compliance engineer. DNR Air Contacts assigned to the facility, including the air compliance engineer, can be found in the Air Permit Search database. Staff may be reassigned without notice, so the facility is responsible for confirming the assigned air compliance engineer for each notification.

Water Requirements

If a crusher or sand and gravel plant is going into a new nonmetallic mine, there are important wetland and waterway permits that must be issued for the mine itself. If the site is in or near a waterway or wetland, a permit is needed to dredge, create a pond or grade in excess of 10,000 feet. Go to the waterway mining page for more information.

The crushers and sand and gravel plants will need to obtain storm water discharge permits when activities like water spray controls or sand washing is involved. You must apply for an industrial Wisconsin Pollutant Discharge Elimination System (WPDES) permit If you have any of the following water discharges: mine dewatering, sand/gravel washing, vehicle wash water, noncontact cooling water, dust suppression water, scrubber water, or other industrial process wastewater. There is a combined general permit for industrial process wastewater and storm water. Review the general permit and its fact sheet:

  • (Nonmetallic) Mining and/or Processing General Permit, WPDES General Permit No. WI-0046515-07-0
  • Description of what processes are covered by the general permit and conditions included in the permit: Fact sheet

If only some of the listed sources of wastewater or storm water contamination are present, the plant may qualify for a general permit. Complete the General Permit applicability survey, to see if the plant activities are covered.

A new sand mine that will wash sand may need to consider the high capacity well permit if they need to pull more than 100,000 gallons per day or have a combination of wells on the site (excluding residential or fire protection) that will exceed that level. Review the information on the High Capacity Wells webpage to ensure you have all the necessary permits.

All water permits are submitted through the ePermits portal. Before applying for a permit, the facility contact must obtain a Wisconsin User ID. Go to DNR's Switchboard to gain access.

Other regulations

Additional resources