Wis. Admin. Code Department of Natural Resources § NR 216.21 - Applicability and exclusions

(1) POINT SOURCES. This subchapter applies to point sources which discharge storm water associated with industrial activity to the waters of the state, either directly or via a separate storm sewer system.
(2) CATEGORIES. This subchapter applies to discharges originating from the industrial facilities belonging to categories identified in pars. (a) and (b).
(a) Tier 1 categories include all of the following:
1. Heavy manufacturers defined by their primary Standard Industrial Classification (SIC) Code, which represents the primary income-producing activity at the facility, listed in Table 1:

Table 1 Tier 1 Heavy Manufacturers




Lumber &Wood Products


Paper & Allied Products


Chemicals & Allied Products


Petroleum Refining &Related Industries


Leather Tanning & Finishing


Stone, Clay, Glass & Concrete Products


Primary Metal Industries


Fabricated Structural Metal


Ship & Boat Bldg. & Repair

Note: Facilities in SIC Codes 2434, 2650-2659, 2670-2679, 2830-2839, 2850-2859, 2951, 3230-3239, 3271-3273 are included in s. NR 216.21(2)(b).

2. Facilities involved in the recycling of materials such as metal scrap yards, battery reclaimers, salvage yards and automobile junk yards, including those classified in SIC Codes 5015 and 5093.
3. Facilities with bulk storage piles for coal, metallic and non-metallic minerals and ores, and scrap not otherwise covered under this subchapter, such as those associated with freight transportation, SIC Code 4400-4499, and wholesale trade, SIC Code 5052.
(b) Tier 2 categories include all of the following:
1. Manufacturing facilities defined by Table 2:

Table 2 Tier 2 Light Manufacturers




Food & Kindred Products


Tobacco Products


Textile Mill Products


Apparel & Other Textile Products


Wood Kitchen Cabinets


Furniture & Fixtures


Paperboard Containers & Boxes


Misc. Converted Paper Products


Printing, Publishing, & Allied Industries




Paints & Allied Products


Rubber & Misc. Plastics Products


Leather & Leather Products


Products of Purchased Glass


Fabricated Metal Products


Industrial & Commercial Machinery & Computer Equipment


Electronic & Other Electrical Equipment & Components


Transportation Equipment


Instruments & Related Products


Misc. Manufacturing Industries


Farm Product Warehousing & Storage


Refrigerated Warehousing & Storage


General Warehousing & Storage

Note: Facilities in SIC Codes 3110-3119, 3441 and 3730-3739 are included in s. NR 216.21(2) (a) 1.

2. Transportation facilities defined by Table 3 that have vehicle maintenance shops, equipment cleaning operations or airport de-icing operations. This subchapter only applies to those portions of these facilities that are involved in vehicle maintenance including rehabilitation, mechanical repairs, painting, fueling, lubrication and associated parking areas, involved in cleaning operations or de-icing operations, or that are listed as source areas under s. NR 216.27(3) (e):

Table 3 Tier 2 Transportation Facilities




Railroad Transportation


Local & Interurban Passenger Transit


Trucking & Warehousing


U.S. Postal Service


Water Transportation


Transportation By Air


Petroleum Bulk Stations &Terminals

Note: Facilities in SIC Codes 4221, 4222 and 4225 are included in s. NR 216.21(2) (b) 1.

a. Facilities defined by Table 4, including active and inactive mining operations and oil and gas exploration, production, processing or treatment operations or transmission facilities. This subchapter only applies where storm water runoff has come into contact with any overburden, raw material, intermediate product, finished product, by-product or waste material located on the site of the operations.

Table 4 Tier 2 Mining, Oil and Gas Operations




Metal Mining


Coal Mining


Oil & Gas Extraction


Non-metallic Minerals, except fuels

b. This subchapter does not apply to non-coal mining operations which have been released from applicable state or federal reclamation requirements after December 17, 1990; nor to coal mining operations released from the performance bond issued to the facility by the appropriate surface mining control and reclamation act authority under 30 USC 1201 et seq. and 16 USC 470 et seq. Production, processing or treatment operations or transmission facilities associated with oil and gas extraction are included only if there has been a discharge of storm water containing a quantity of a pollutant reportable pursuant to 40 CFR 110.64, 40 CFR 117.21 or 40 CFR 302.6, or if a storm water discharge contributed to a violation of a water quality standard.
4. Facilities subject to storm water effluent limitation guidelines, new or existing source performance standards or toxic pollutant effluent standards under 33 USC 1251, 1311, 1314(b) and (c), 1316(b) and (c), 1317(b) and (c), 1326(c), except those facilities classified as a Tier 1 pursuant to sub. (2) (a).
5. Treatment works treating domestic sewage or any other sewage sludge or wastewater treatment device or system, used in the storage, treatment, recycling and reclamation of municipal or domestic sewage, including lands dedicated to the disposal of sewage sludge that are located within the confines of the facility, with a design flow of one million gallons per day or more, or required to have an approved pretreatment program. Not included are farm lands, domestic gardens or lands used for sludge management where sludge is beneficially reused and which are not physically located in the confines of the facility, or areas that are in compliance with 33 USC 1345.
6. Hazardous waste treatment, storage and disposal facilities, including those operating under a license under s. 291.25, Stats.
7. Landfills, land application sites and open dumps that receive or have received any industrial waste from any of the facilities identified in this section, including those subject to regulation under subtitle D of the resource conservation and recovery act, 42 USC 6901 et seq., or ch. 289, Stats. For the purposes of this subdivision, "industrial waste" means a disposed material generated by any of the facilities identified in this section including construction and demolition waste from a construction site regulated under subch. III. The term does not include placement of recycled material used during construction.
8. All steam electric power generating facilities, including coal handling sites but not including off-site transformer or electric substations.
9. Facilities described in SIC code 2951 for asphalt paving mixes and block, and facilities described in SIC codes 3271, 3272 and 3273 for cement products.
10. Facilities previously classified as tier 1 dischargers that are subsequently classified as tier 2 under s. NR 216.23(3).
11. Discharges determined by the department to be significant contributors of pollutants to waters of the state.
(a) Discharges composed entirely of storm water are not storm water discharges associated with industrial activity if there is no exposure of industrial materials and activities to storm water, and the discharger satisfies the conditions in pars. (b) to (e). "No exposure" means that all industrial materials and activities are protected by a storm resistant shelter to prevent exposure to storm water. Industrial materials or activities include material handling equipment or activities, industrial machinery, raw materials, intermediate products, by-products, final products or waste products. Material handling activities include the storage, loading and unloading, transportation or conveyance of any raw material, intermediate product, final product or waste product.
(b) Qualification. To qualify for this exclusion, the operator of the discharge shall do all of the following:
1. Provide a storm resistant shelter to protect industrial materials and activities from exposure to storm water.
2. Complete and sign, in accordance with s. NR 216.22(7), a certification that there are no discharges of storm water contaminated by exposure to industrial materials and activities from the entire facility, except as provided in par. (c).
3. Submit an initial "no exposure" certification to the department at least 14 working days prior to the start of industrial operations on a form available from the department as specified under s. NR 216.006.

Note: The department's no exposure certification form, Form 3400-188, requests necessary information to be consistent with federal requirements and US EPA NPDES Form 3510-11. US EPA has published a guidance document entitled Guidance Manual for Conditional Exclusion from Storm Water Permitting Based On "No Exposure" of Industrial Activities to Storm Water, EPA 833-B-00-001, dated June 2000. This guidance is available from the US EPA website at https://www.epa.gov/npdes/guidance-manual-conditional-exclusion-stormwater-permitting-based-no-exposure-industrial. The department no exposure certification form is available from the department website at https://dnr.wisconsin.gov/topic/Stormwater/industrial/forms.html or by calling 1-888-936-7463.

4. Submit the signed certification to the department once every 5 years.
5. Allow the department to inspect the facility to determine compliance with the "no exposure" conditions.
6. Allow the department to make any "no exposure" inspection reports available to the public upon request.
7. For facilities that discharge through an MS4, upon request, submit a copy of the certification of "no exposure" to the MS4 operator, as well as allow inspection and public reporting by the MS4 operator.
(c) Industrial materials and activities not requiring storm resistant shelter. To qualify for this exclusion, storm resistant shelter is not required for any of the following:
1. Drums, barrels, tanks and similar containers that are tightly sealed, provided those containers are not deteriorated and do not leak. "Sealed" means banded or otherwise secured and without operational taps or valves.
2. Adequately maintained vehicles used in material handling.
3. Final products, other than products that would be mobilized in storm water such as rock salt.
(d) Limitations.
1. This conditional exclusion from the requirement to obtain a permit under this subchapter is available on a facility-wide basis only, not for individual outfalls. If a facility has some discharges of storm water that would otherwise be "no exposure" discharges, individual permit requirements may be adjusted by the department accordingly.
2. If circumstances change and industrial materials or activities become exposed to storm water, the conditions for this exclusion no longer apply. The discharge then becomes subject to enforcement as an unpermitted discharge. Any conditionally exempt discharger who anticipates changes in circumstances shall submit a notice of intent to the department 14 or more working days prior to the change of circumstances and in accordance with s. NR 216.22.

Note: A facility that has claimed a condition of "no exposure" should routinely inspect its facility to verify that it continues to operate in a condition of "no exposure."

3. Notwithstanding the provisions of this subsection, the department retains the authority to require permit authorization and deny this exclusion upon making a determination that the discharge causes, has a reasonable potential to cause, or contributes to an exceedence of an applicable water quality standard, including designated uses.
(e) Certification. The "no exposure" certification shall include all of the following information, at a minimum, to aid the department in determining if the facility qualifies for the "no exposure" exclusion:
1. The legal name, address and phone number of the discharger.
2. The facility name, address, the county name where the facility is located, and the latitude and longitude where the facility is located.
3. The certification shall indicate that none of the following materials or activities are, or will be in the foreseeable future, exposed to precipitation:
a. Using, storing or cleaning industrial machinery or equipment, and areas where residuals from using, storing or cleaning industrial machinery or equipment remain and are exposed to storm water.
b. Materials or residuals on the ground or in storm water inlets from spills and leaks.
c. Materials or products from past industrial activity.
d. Material handling equipment, except adequately maintained vehicles.
e. Materials or products during loading and unloading or transporting activities.
f. Materials or products stored outdoors, except final products intended for outside use such as new cars, where exposure to storm water does not result in the discharge of pollutants.
g. Materials contained in open, deteriorated or leaking storage drums, barrels, tanks and similar containers.
h. Materials or products handled or stored on roads or railways owned or maintained by the discharger.
i. Waste material, except waste in covered, non-leaking containers.
j. Application or disposal of process wastewater unless otherwise permitted.
k. Particulate matter or visible deposits of residuals from roof stacks or vents not otherwise regulated such as under an air quality control permit, and evident in the storm water outflow.
4. All "no exposure" certifications shall include the following certification statement, and be signed in accordance with the signatory requirements of s. NR 216.22(7): "I certify under penalty of law that I have read and understand the eligibility requirements for claiming a condition of "no exposure" and obtaining an exclusion from permitting requirements under subch. II of ch. NR 216; and that there are no discharges of storm water contaminated by exposure to industrial activities or materials from the industrial facility identified in this document, except as allowed under s. NR 216.21(3) (c). I understand that I am obligated to submit a "no exposure" certification form once every five years to the department and, if requested, to the operator of the local MS4 into which this facility discharges (where applicable). I understand that I must allow the department or MS4 operator where the discharge is into the local MS4, to perform inspections to confirm the condition of no exposure and to make such inspection reports publicly available upon request. I understand that I must obtain permit coverage under subch. II of ch. NR 216, prior to any point source discharge of storm water from the facility. I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based upon my inquiry of the person or persons who manage the system, or those persons directly involved in gathering the information, the information submitted is to the best of my knowledge and belief true, accurate and complete. I am aware there are significant penalties for submitting false information, including the possibility of fine and imprisonment."
(5) EXCLUSIONS. This subchapter does not apply to any of the following:
(a) Diffused surface drainage or agricultural storm water discharges.
(b) Non-storm water discharges at the outfall covered under an individual or general WPDES permit, including contact cooling water, non-contact cooling water, other process wastewaters or sewage.
(c) Non-storm water discharges at an outfall for which coverage under an individual or general WPDES permit is not required, including landscape irrigation, diverted stream flows, uncontaminated groundwater infiltration, uncontaminated pumped groundwater, discharges from potable water sources, foundation drains, air conditioning condensation, irrigation water, lawn watering, individual residential car washing, flows from riparian habitats and wetlands and fire fighting.
(d) Inactive, closed or capped landfills that have no potential for contamination of storm water. The department shall make a determination of contamination potential on a case-by-case basis.
(e) Remedial action discharges or discharges authorized by a WPDES permit for discharging contaminated or uncontaminated groundwater.
(f) Discharges of hazardous substances that are required to be reported under ch. NR 706.
(g) Areas located on plant lands that are segregated from the industrial activities of the plant, such as office buildings and accompanying parking lots, if the drainage from the segregated areas is not mixed with contaminated storm water drainage.
(h) Storm water discharges into a municipal combined sewer system.


Wis. Admin. Code Department of Natural Resources § NR 216.21
CR 03-028: cr. Register July 2004 No. 583, eff. 8-1-04. Amended by, correction in (3) (b) (3) (Note) made under s. 35.17(2), Stats., Register November 2017 No. 743, eff. 12/1/2017 Amended by, CR 21-027: am. (2) (b) 1., 7., (3) (b) 3., (e) 2., r. (4) Register March 2022 No. 795, eff. 4/1/2022

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