To:John Borovsky

From:Mike Hansel

Subject:Draft Wastewater Discharge and Treatment Optionsand Strategy – RS27 Part I: Overview of Current Regulatory and Legal Climate

Date:October 16, 2018

Project:23/69-862

c:

Memorandum

To:PolyMet Mining EIS File 23/69-862-006-001

From:Mike Hansel

Subject:Draft Wastewater Discharge and Treatment Optionsand Strategy – RS27 Part I: Overview of Current Regulatory and Legal Climate

Date:October 16, 2018

Project:23/59-862

cc:Don Richard, Mark Deady, Christine Pint

Overview

This is the first of a series of four technical memoranda which will describe the options for discharges from the PolyMet mine site and plant site, and requirements for treatment at each of those discharge options. The final technical memorandum will describe a strategy which will accomplish the following goals:

  • Quantity: Provide adequate volume of disposal of the range of volumes of water requiring discharge from the mine site and plant site operations
  • Quality: Provide adequate treatment either at the point of generation, point of discharge and/or intermediate point(s) to assure compliance with effluent treatment requirements, particularly for mercury
  • Legality: Comply with Clean Water Act and recent court decisions on prohibitions of new or expanded discharges which may “cause or contribute” to impaired waters, and/or with enacted Total Maximum Daily Load (TMDL) Plans.

The series of technical memorandum are organized as follows:

  • Part I – Overview of current regulatory and legal climate
  • Part II – Options for accommodating the expected quantity (volume and rate) of water (wastewater and storm water) requiring discharge from the mine site and plant site operations
  • Part III -- Summary of current water quality discharge requirements for selected quantity options and summary of compliance history
  • Part IV – Proposed discharge and treatment strategy including treatment/pre-treatment requirements for selected quantity options

Part I -- Current Regulatory and Legal Climate

CWA Limitations on Discharge

The Clean Water Act generally prohibits new or expanded discharges to waters which do not meet water quality requirements (impaired waters), requires states to list waters which do not meet water quality standards (the “303(d) list”) and requires states to develop plans to return impaired waters to compliance with water quality standards. These plans are called “Total Daily Maximum Load” or TMDL Plans, because they set the maximum amount of an impairing pollutant which may be discharged from point sources (publicly owned treatment works or POTWs, industrial discharges, stormwater discharges and NPDES permitted confined animal feeding operations (CAFOs), and non-point sources (runoff from land other than permitted stormwater discharges).

Section 122.4 (d), (g) and (i) of Title 40 of the Code of Federal Regulations provides:

“No permit may be issued:

(d) When the imposition of conditions cannot ensure compliance with the applicable water quality requirements of all affected States;

…

(g) For any discharge inconsistent with a plan or plan amendment approved under section 208(b) of CWA;

…

(i) To a new source or a new discharger, if the discharge from its construction or operation will cause or contribute to the violation of water quality standards. The owner or operator of a new source or new discharger proposing to discharge into a water segment which does not meet applicable water quality standards or is not expected to meet those standards even after the application of the effluent limitations required by sections 301(b)(1)(A) and 301(b)(1)(B) of CWA, and for which the State or interstate agency has performed a pollutants load allocation for the pollutant to be discharged, must demonstrate, before the close of the public comment period, that:

(1) There are sufficient remaining pollutant load allocations to allow for the discharge; and

(2) The existing dischargers into that segment are subject to compliance schedules designed to bring the segment into compliance with applicable water quality standards. The Directormay waive the submission of information by the new source or new discharger required by paragraph (i) of this section if the Director determines that the Director already has adequate information to evaluate the request. An explanation of the development of limitations to meet the criteria of this paragraph (i)(2) is to be included in the fact sheet to the permit under §124.56(b)(1) of this chapter.

Specifically, the Clean Water Act requires that new or expanded discharges to listed waters either:

1. Meet the requirements of an approved TMDL Plan; or, in the absence of a TMDL Plan,

2. Demonstrate that they do not “cause or contribute” to the impairment in listed waters.

Requirement #2 was recently upheld by the Minnesota Court of Appeals. In an August 9, 2005 ruling “A04-233 In the Matter of the Cities of Annandale and Maple Lake NPDES/SDS Permit Issuance for the Discharge of Treated Wastewater, and Request for Contested Case Hearing”, the court ruled that the MPCA had erred in issuing an NPDES permit for a new discharge for the combined Annandale –Maple Lake POTW, because it would contribute to the continued impairment of the Crow River and the Mississippi River. That case is currently under appeal to the Minnesota Supreme Court, with a decision expected in spring, 2006.

The court ruled that “Because it does not break down into smaller components, phosphorus persists in a watershed to a greater degree than other pollutants. Thus, the PCA concedes that this phosphorus will affect the LakePepin watershed.” There seems little doubt, barring a reversal on appeal, that the courts would treat mercury any differently – because it does not break down into smaller components, it would persist and cause or contribute to impairments on listed waters.

Status of Impaired Waters and TMDL Plans in Minnesota

Many of the waters in the project area are impaired for mercury, in that they do not meet the Minnesota fish consumption advisory limit of 0.2 mg/kg fish tissue. Others may be impaired because they do not meet the water quality standards of 1.3 ng/L in the Lake SuperiorBasin or 6.9 ng/L elsewhere in the state.

The impaired waters in the project area include the St. Louis River, ColbyLake, Whitewater Reservoir, Embarrass River.

Other waters which are not impaired, like the PartridgeRiver and Second Creek, flow into impaired waters such as the St. Louis River and/or ColbyLake. New or expanded discharges to these unimpaired waters, which flow into impaired waters, must also make a demonstration that they do not “cause or contribute” to impairments in downstream impaired waters. For substances which are chemically or biologically degraded, a demonstration that the substance no longer exists (or no longer exists in the impairing form) is sufficient. This was upheld in the AnnandaleMapleLake decision for oxygen depleting substances. For substances like mercury (or phosphorus), which do not degrade, a similar showing might be attempted, but the courts have not made a determination of how far downstream an analysis needs to be conducted.

Currently there is no approved TMDL Plan for mercury in Minnesota. In 2005, the MPCA put a draft “regional” mercury TMDL Plan on public notice, and received over 900 comments, after a twice-extended comment period. A contested case hearing was requested, then withdrawn. MCPA staff are currently preparing responses to the public comments, and may convene a stakeholders forum to discuss paths forward.

It is uncertain whether a “regional” mercury TMDL Plan would meet the requirements of the Clean Water Act. In 2005, MPCA approved and sent to the US EPA, Region V, a regional TMDL Plan for fecal coliform for the entire southeastern Minnesota region. US EPA Region V approved the TMDL Plan, but was subsequently sued by the MinnesotaCenter for Environmental Advocacy. In June, 2005 in MCEA v. US EPA Region V and MPCA (Civil No. 03-5450 (DWF/SRN), the US District Court for the District of Minnesota remanded the regional fecal coliform TMDL Plan back to the MPCA and US EPA for revision. The court required, among other things, that “The revised TMDL shall be established at a level necessary to implement the applicable water quality standards for each reach impaired with fecal coliform contamination.” (emphasis added).

Given this ruling, and the current state of affairs, it is doubtful that a mercury TMDL Plan for any waters of the state impaired for mercury will be approved before sometime in 2007. Thus, project discharges will need to show that they do not “cause or contribute” to water quality violations.

Policies related to “Cause or Contribute” to Water Quality Violations

Given the recent decisions by the courts, the MPCA has developed guidance for discharges of phosphorus into waters impaired for nutrients (or impacts of nutrients such as low dissolved oxygen or impairments to fish or other biota). That guidance “Guidance for Issuing NPDES Permits for Discharge to Impaired Waters: Expanding Facilities” (Water Quality, Wastewater Permits, General Information 1-14, October 2005), MPCA sets forth the following policy:

“Limits for Affected Facilities

All facilities are capped at their existing phosphorus mass using the Average Wet Weather Design Flow (AWWD) for municipal sites and Average Annual Design Flow (AAD) for industrial sites. Also, proposed expansions

  • Greater than 1,800 pounds of phosphorus per year must meet the 1mg/L phosphorus concentration limit.
  • Less than 1,800 pounds per year are capped at their existing phosphorus mass, but will not receive a 1mg/L phosphorus concentration limit.*

* This approach is consistent with the current MPCA Board-approved Phosphorus Strategy and proposed Water Quality rules.”

MPCA suggests the following alternatives:

“Discharge Alternatives

To meet the requirements of Federal Regulation 40 C.F.R. 122.44(d)1, affected facilities have the following options

1. Provide treatment to meet the mass limit and, if discharging greater than 1,800 pounds of phosphorus per year, provide treatment to meet a 1mg/L concentration limit.

2. Eliminate some or all surface water discharge by using land treatment options such as spray irrigation, rapid infiltration basin or soil treatment systems.

3. Initiate pollution prevention actions to reduce source pollutant to meet the mass limit.

4. Discharge to a permitted wastewater treatment facility that has available phosphorus capacity.”

The MPCA has officially applied this same guidance with respect to mercury when issuing two recent permits: Mesabi Nugget and Northshore Mining. In both cases, the mass of mercury discharge did not increase, and the facilities were required to meet water quality standards at the end of the discharge pipe (no mixing zone).

GLI Limitations on Discharge

The Great Lakes Initiative or GLI is a collaboration by the United States, the states bordering the Great Lakes, cities tribes and Canada (federal, provincial and local governments) to improve the Great Lakes.

Water Quality

As noted above, the water quality limitation for discharges of mercury to the Lake SuperiorBasin are limited to 1.3 ng/L. As a practical matter, MPCA staff have recently written permit limitations, assuming twice monthly sampling and analysis of mercury, as 1.8 ng/L on a quarterly average basis, and 3.2 ng/L on a quarterly maximum basis.

Pollutant Mass

Also as noted above in the MPCA guidance, MPCA will allow no increase in mass of mercury from existing discharges. In the case of the Mesabi Nugget Permit, not only was the flow from an existing discharge decreased (with water evaporating in a scrubber and cooling towers), but the concentration was lowered with treatment to meet the GLI water quality standard. In the case of Northshore Mining, the concentration was already well under the GLI water quality standard, and Northshore needed to increase the volume of discharge. In that case, the MPCA determined that the treated water from Northshore was better than both the water in the Beaver River and in runoff from surrounding areas, and that any increase in mass was not “significant” and was probably not measurable. The MPCA also determined that Northshore Mining had not been discharging the maximum amount of water permitted under federal categorical standards, and so could “catch up” the volume of water which it could have been discharging over the past 20+ years, since creation of the Mile Post 7 tailings basin. In addition, in order to show non-degradation of outstanding resource waters (e.g. Lake Superior, to which most of the waters in the vicinity of the project drain), MPCA has been requiring a showing of no increase in pollutant mass. Thus, even if a TMDL were approved for mercury for the Lake SuperiorBasin, non-degradation standards would impose similar limits.

GLI Limitations on appropriations or diversions outside of Great Lakes

The Great Lakes Charter provides that any appropriation for consumptive uses or diversion of water outside of the basin of more than 5 million gallons/day requires the approval of all Great Lakes and Provinces. Appropriation for consumptive uses or diversions of more than 2 million gallons/day require consultation with the Great LakesStates and Provinces.

MPCA staff have indicated that recent negotiations have reduced the level for consultation to 1 million gallons/day, and that while not officially adopted, it is being observed by Minnesota and the rest of the Great Lakes States. MPCA staff hold little hope that concurrence could be obtained in any timely manner from the affected states and provinces, and have discouraged large scale diversions, including some that have recently been proposed to avoid meeting the GLI concentration limits for mercury.

Conclusions and Recommendations

Given the current regulatory and legal climate, it seems that there is little, if any chance of permitting a new or expanded discharge of mercury in the Lake SuperiorBasin. Permits issued recently that have not been appealed (Mesabi Nugget and Northshore Mining) have been existing, permitted discharges, and followed the MPCA phosphorus guidance:

  • No increase in mass of mercury discharged
  • Meet mercury water quality standards at end of pipe.

The current permitted discharge from the Tailings basin is an existing permitted discharge. Assuming that the concentration of mercury in the discharge remains the same or decreases (likely, given the very large mass of tailings and their affinity for mercury) and assuming that the volume of water decreases (because there will be no water in Cell 2W and the seepage collection systems will be upgraded), there will be a decrease in the mass of mercury discharged. If additional water can be discharged, such that the mass of mercury is the same or less than that currently permitted to be discharged, additional water may be discharged from the tailings basin.

The most certain and quickest route to permitting will be to utilize existing permitted discharge, and work to ensure that there is no increase in mercury mass, and that water quality standards are met end of pipe.

Fortunately, there are a number of existing, permitted municipal and industrial discharges which are not being used to their full permitted capacity, or which could with treatment, meet water quality standards at end of pipe and have no increase in mercury mass loading. One or more of these existing discharges could be used, perhaps with treatment, to accommodate additional discharge from the PolyMet operations.

Alternatively, a site-specific TMDL could be conducted for the upper reach of the PartridgeRiver, down to and perhaps including Colby and WhiteWaterLake. The TMDL could include sufficient reserve capacity to allow new and expanded discharges to the PartridgeRiver.

It should be noted that for pollutants which are not impairing (e.g. for which the receiving water is not listed as impaired for that pollutant), it is acceptable to increase the mass and even the concentration of those pollutants. In fact, variances have been issued in certain circumstances for Class 3 and 4 pollutants (non-metals – things like total dissolved solids, hardness, alkalinity, specific conductance, chlorides) when discharges do not meet water quality standards. Non-degradation requirements must still be met, of course.

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