Public Notice of Intent to Reissue NPDES and SDS Permit to Dyno

Public Notice of Intent to Reissue Wastewater Permit MN0060704

General information Public comment period begins: November 5, 2019 Public comment period ends: December 4, 2019 (4:30 p.m.) Current permit issued: August 4, 2011 Current permit expiration date: July 31, 2016

The Minnesota Pollution Control Agency (MPCA) Commissioner has made a preliminary determination to reissue this permit for a term of approximately five years.

Name and address of Permittee: Facility name and location: MPCA contact person: Dyno Nobel Inc. Dyno Nobel Inc. Danielle Drussell 2795 East Cottonwood Parkway, Suite 500 5392 Vermillion Trail Industrial Division Salt Lake City, UT 84121 Biwabik, MN 55708 Minnesota Pollution Control Agency St. Louis County 525 Lake Avenue South, Suite 400 T058N, R16W, Section 013 Duluth, MN 55802 Phone: 218-302-6611 Email: [email protected]

File manager phone: 651-757-2728 or 1-844-828-0942

A draft permit is available for review on the MPCA Public Notices webpage at http://www.pca.state.mn.us/publicnotices or at the MPCA office address listed under the MPCA contact person. The MPCA will mail or email a copy of the draft permit upon request. Comments, petitions, and other requests must be received at the MPCA in writing on or before the public comment period end date and time identified above.

Watershed: St. Louis River Receiving water: Embarrass River (Embarrass Lake) - Class 2Bg, 3C, 4A, 4B, 5, 6 water

Description of permitted facility The principal activity at this facility is the manufacture and distribution of bulk ammonium-nitrate oxidizer emulsions and blasting agents for use in mining and construction in northern Minnesota and Canada. The primary raw materials, aqueous ammonium-nitrate solution, solid granular ammonium-nitrate prill, solid sodium nitrate granules, fuel oil, mineral oil, emulsifier and small amounts of dye, are processed by proportional blending to create bulk explosive emulsions. The bulk oxidizer emulsions are combined with pre-packaged blasting agents, boosters, detonators and shock tubes (that Dyno redistributes without repackaging) at the mining or construction sites to perform blasting. The facility produces on average 252,000 lb/day of explosives.

The water source for the facility is an on-site well with a rate of supply of less than 10,000 gallons per day (gpd). Plant utility wastewater generated at the facility authorized for discharge under this permit include boiler room floor wash water, condensate from the steam heating of rail cars, and boiler blowdown water. There are no wastewater discharges from the plant where bulk oxidizer emulsions and blasting agents are manufactured. All wastewaters, spills, etc. are captured in a closed-loop collection system and recycled as a component of the plant's products. Boiler blowdown water is collected in an underground storage tank prior to discharge to allow for heat dissipation. All authorized plant utility wastewater is combined at one outfall (SD001).

Since the previous permit, the facility has constructed a series of three rock check dams along the discharge flow path upstream of the compliance point to remove solids from the discharge. Enhanced vegetation along the discharge flow path to attenuate chemical constituents in the discharge has also been promoted and monitored. In addition, a v-notch weir has been installed immediately upstream of the compliance point to both capture solids and provide accurate flow measurements. The average utility wastewater flow from discharge SD001 is approximately 4,100 gpd to an unnamed wetland, which ultimately flows to the St. Louis River via the Embarrass River. Stormwater runoff also enters the open tiling that utility wastewater flows through leading to the outfall, which is designated as SD002. The average and maximum authorized flow rates from SD001 are 4,100 gpd and 31,000 gpd, respectively.

https://www.pca.state.mn.us • 651‐296‐6300 • 800‐657‐3864 • Use your preferred relay service • Available in alternative formats Page 1 of 2 Even though this is an increase from the last permit cycle, non-degradation does not apply, as the compliance point was moved downstream and is now capturing more stormwater sources and upwelling of groundwater. The facility is unchanged and is not using nor discharging more water.

This permit includes surface water monitoring (SW001 and SW002) of the receiving water wetland complex to verify that the wetland is not adversely impacted. The primary concern is the alteration of the background pH and buffering capacity.

Truck wash water generated from the facility is routed through a series of three settling basins and stored in a lined retention pond. Dyno Nobel, Inc. coordinates acceptance and disposal of the solids with a licensed septic pumping service for disposal at a licensed wastewater treatment plant. Sewage at the facility is treated and disposed via three on-site septic systems.

In lieu of obtaining coverage under both the General Permit and the individual NPDES permit, the MPCA has added the necessary industrial stormwater requirements language and limits and monitoring to this permit so that coverage under this NPDES permit alone will cover both permits. An additional discharge station (SD 002) has been created to monitor stormwater. The preliminary determination to reissue this Wastewater permit is tentative.

Procedure for public participation As stated in Minn. R. chs. 7000 and 7001, there are three formal procedures for public participation in the MPCA's consideration of this matter. Interested persons may: (1) Submit written comments on the draft permit. (2) Petition the MPCA to hold a public informational meeting. (3) Petition the MPCA to hold a contested case hearing.

Submitting written comments To submit comments or petitions to the MPCA through the mail or email, you must state: (1) Your interest in the permit application or the draft permit. (2) The action you wish the MPCA to take, including specific references to the section of the draft permit you believe should be changed. (3) The reasons supporting your position, stated with sufficient specificity as to allow the MPCA to investigate the merits of the position.

Public informational meeting A public informational meeting is an informal meeting during which interested persons can ask questions concerning the proposed facility. MPCA staff will be present to provide information. If an interested person would like the MPCA to hold a public informational meeting, the person should include all information identified above and in addition include a statement of the reasons the person desires the MPCA to hold a public informational meeting and the issues that the person would like the agency to address at the public informational meeting.

Contested Case Hearing A contested case hearing is a formal proceeding before an administrative law judge empowered to advise the MPCA regarding issues of fact. As described in Minn. R. 7000.1800, persons who submit petitions for a contested case hearing must also state the issues they propose to address in a contested case hearing, the specific relief requested or resolution of the matter, and the reasons (which may be in the form of proposed findings) supporting an MPCA decision to hold a contested case hearing. Failure to comply with these rules exactly may result in a denial of the request. To the extent known, the petitioner may also submit a list of prospective witnesses to be called at a hearing, a proposed list of publications, references, or studies to be introduced at a hearing and the approximate time required for the petitioner to present the matter at a hearing. The decision whether to hold a contested case hearing will be made under Minn. R. 7000.1900.

https://www.pca.state.mn.us • 651‐296‐6300 • 800‐657‐3864 • Use your preferred relay service • Available in alternative formats Page 2 of 2