MN Pollution Control Agency

Rationale

Water Quality Permits: Stormwater

RConstruction Stormwater: Any project proposer that plans to disturb more than one acre of land needs to apply for a Construction Stormwater National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) permit. If your project is under an acre in size, but is part of a larger common plan of development, you will also need a permit. More information on CSW permits can be found on MPCA’s website here: https://www.pca.state.mn.us/business-with-us/construction-stormwater

Industrial Stormwater: Facilities in specific industries that store materials, waste, or equipment outdoors are subject to industrial stormwater regulations administered by the MPCA. These facilities must take steps to monitor and manage stormwater on their properties where stormwater may come into contact with harmful pollutants including toxic metals, oil, grease, de-icing salts, and other chemicals. Industrial stormwater permittees in Minnesota are regulated by a general permit that is reissued every five years. A project proposer would need to apply for an Industrial Stormwater (ISW) general NPDES/SDS permit for any activity as required under the permit. More information can be found on the MPCA ISW webpage at: https://www.pca.state.mn.us/business-with-us/industrial-stormwater

Wastewater

Any waste and wastewater resulting from gas well production including, but not limited to: surface water, groundwater, or any other liquid, gas, or chemical must be in accordance with Minnesota Department of Health’s statutory gas well language at Minn. R. 4725.2050 administered by Minnesota Department of Health. This does not prohibit the injection of approved drilling fluids as provided in Subd. 9 for drilling and development of a gas well.

Options for disposal of wastewater associated with a gas well include:

Class 2 Injection well. Class 2 injection wells are currently permitted and regulated under the US Environmental Protection Agency (EPA). Minnesota does not have Class 2 injection well primacy so any permit would need to be obtained through US EPA. More information can be obtained here: https://www.epa.gov/uic/class-ii-oil-and-gas-related-injection-wells

A project proposer can contain and dispose of any wastewater at an authorized wastewater treatment facility (WWTF) willing to accept the waste.

A project proposer can apply for an individual NPDES/SDS permit to treat and surface discharge any wastewater. Effluent Limit Guidelines 40 CFR 435 do not apply to this industry. Therefore, an individual NPDES/SDS permit developed with best professional judgement (BPJ) and water quality based effluent limits (WQBELs) is appropriate.

Air Quality Permits

If there is equipment for on-site electricity generation (e.g., diesel generator), internal combustion engine requirements in state (Minn. R. 7011.2300) and federal rules (40 CFR 60 Subpart IIII or JJJJ; 40 CFR 63, Subpart ZZZZ) would likely apply and an air permit would likely be required. While it does not appear that federal standards and guidelines for crude oil and natural gas facilities (40 CFR Subpart OOOO) would apply, an official EPA applicability determination has not been made. If any of these federal requirements would apply, an air permit would likely be required. The exact state and federal standards and permitting requirements cannot be determined without having site-specific information on all the equipment, how the facility will be operated, and all potential air emissions.

Currently, there are no known regulatory gaps that exist unless the MPCA would like to regulate the greenhouse gases (e.g., CO2 and CH4) that may be released. Given that the well gas contains the greenhouse gases methane and carbon dioxide (CO2) (approximately 5% and 71%, respectively), the MPCA may consider regulating those gases to minimize their release to the atmosphere and maximize their beneficial use. Where recovery and use of the methane is not feasible, converting the methane to CO2 through flaring may be the next best option. Flaring, sometimes used in managing landfill gases, would also provide the benefit of reducing or eliminating non-methane hydrocarbons, air toxics, and odor causing compounds that may be found at lower concentrations in the well gas and that would otherwise be released to the atmosphere.

Aboveground Storage Tanks (AST)

The MPCA’s AST rules as written do not allow the MPCA to regulate gases stored in tanks in a permit; MPCA’s permits as currently written would not be applicable to storage of gases due to the nature of gases. The MPCA’s AST program was setup as a water (i.e., surface and groundwater) protection program from inception. This is the same for the small AST program and major facility AST program (i.e., cumulative capacity of one million gallons or more).

The rules that govern the scope and procedures for “major facility substance storage permits” (note: this is the specific rule name for MPCA AST permits) are in:

Minn. R. 7001.0020.H, which is the rule that says MPCA permits are subject to the general MPCA permit procedures in 7001.0010 to .0210 (this applies to all media, for example, air, water, hazardous waste, etc. permits), unless otherwise specified, and

Minn. R. 7001.4200 to .4250, which has the scope and procedures specific to AST permits.

Further, substances which are inherently a gas like helium or hydrogen are not subject to AST permits, per 7001.4205.4 which says, “Substance means any liquid material which is not gaseous or solid at ambient temperature and pressure...”. The reason that gases are excluded from this rule is because AST permits regulate “liquids only” and is reiterated by Minn. R. 7001.4201; the purpose is to protect against entry of stored substances into waters of the state (i.e., groundwater and surface water). In regards to a gas, if it were to escape a tank, it would enter the air but would not enter any water of the state.

In summary, if there are ASTs at either type of operation, exploration or production, which do not add up to one million gallons, a permit is not required, but the tanks are still regulated by Minn Chapter 7151 rules for small ASTs. Therefore, the existing AST rules, as written and intended, will cover AST storage for this type of operation adequately, but regulating the storage of gases is exempt and outside of current AST rule scope. Should regulation of gases be desired, new rules would have to be written.

Solid Waste

No solid waste permits would be required. This is not an industrial activity that treats, transfers, stores, processes, or disposes of solid waste. However, a guidance document on water filter backwash solids has criteria for the disposal level criteria for radium. Should there be a need to dispose of solid waste that has radium contained in, the acceptable radium disposal limit is in guidance only.

Moving forward, the MPCA could consider adding a rule disposal restriction related to radium levels for any waste generated from the gas industry in the section that lists the industrial waste types that must be addressed in the Industrial Solid Waste Management Plans (ISWMPs) in Minn. R. 7035.2535, subp. 5. The disposal level restriction would then have to be included in the facility’s ISWMP if they accept waste from it.