national pollutantdischarge elimination system /state ... (npdes/sds) permit program fact sheet 2...

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Permittee: Rahr Malting Co. Facility Name: Rahr Malting Co. Permit Number: MN0031917 800 West 1st Avenue 800 West 1st Avenue Shakopee, Minnesota 55379 Shakopee, Minnesota 55379

Current Permit Expiration: July 31, 2012

Public Comment Period Begins: August 9, 2012 Period Ends: September 10, 2012

Receiving Water: Minnesota River, Class 2B, 3C, 4A, 4B, 5, and 6 water.

Proposed Action: Permit Reissuance

Permitting ContactScott Knowles, P. E.

525 S Lake Avenue, Suite 400 Duluth, MN 55802

Phone: 218/302‐6651 or 800/657‐3864 Fax: 218/723‐4727

National Pollutant Discharge

Elimination System /State Disposal

System (NPDES/SDS) Permit Program

Fact Sheet

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Table of Contents Purpose and Participation .................................................................................................................. 3

Applicable Statutes ............................................................................................................... 3 Fact Sheet Purpose ............................................................................................................... 3 Public Participation ............................................................................................................... 3

Facility Description ............................................................................................................................. 4 Background Information ....................................................................................................... 4

Facility Location Legal Description ........................................................................... 4 Outfall Location Legal Description ........................................................................... 4 Permitted Facility Map ............................................................................................. 5

Components and Treatment Technology ............................................................................. 7 Current Information ................................................................................................. 7

Flow Schematic ........................................................................................................ 8 Changes to Facility or Operation ............................................................................. 11 Recent Compliance History ...................................................................................... 11 Recent Monitoring History ...................................................................................... 11 Receiving Water ................................................................................................................................. 18 Use Classification .................................................................................................................. 18 Impairments, Listings, and Total Maximum Daily Load Studies ........................................... 19 Existing Permit Effluent Limits ........................................................................................................... 19 Technology Based Effluent Limits ......................................................................................... 19 Water Quality Based Effluent Limits ..................................................................................... 20 Proposed Permit Effluent Limits ........................................................................................................ 21 Technology Based Effluent Limits ......................................................................................... 21 Water Quality Based Effluent Limits ..................................................................................... 22 Additional Requirements ................................................................................................................... 23 Total Facility Requirements ............................................................................................................... 24 Nondegredation and Anti‐backsliding ............................................................................................... 24

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Purpose and Participation Applicable Statutes This fact sheet has been prepared according to the Title 40 Federal Code of Regulations (CFR) §124.8 and §124.56 and Minn R. 7001.0100, Subp. 3 in regards to a draft NPDES/SDS permit to construct and/or operate wastewater treatment facilities and to discharge into waters of the State of Minnesota. Purpose This fact sheet outlines the principal issues related to the preparation of this draft permit and documents the decisions that were made in the determination of the effluent limitations and conditions of this permit. Public Participation You may submit written comments on the terms of the draft permit or on the Commissioner’s preliminary determination. Your written comments must include the following: 1. A statement of your interest in the permit application or the draft permit. 2. A statement of the action you wish the Minnesota Pollution Control Agency (MPCA) to take,

including specific references to sections of the draft permit that you believe should be changed. 3. The reasons supporting your position, stated with sufficient specificity as to allow the

Commissioner to investigate the merits of your position. You may also request that the MPCA Commissioner hold a public informational meeting. A public informational meeting is an informal meeting which the MPCA may hold to help clarify and resolve issues. In accordance with Minn. R. 7000.0650 and Minn. R. 7001.0110, your petition requesting a public informational meeting must identify the matter of concern and must include the following: items 1 through 3 identified above; a statement of the reasons the MPCA should hold the meeting; and the issues you would like the MPCA to address at the meeting. In addition, you may submit a petition for a contested case hearing. A contested case hearing is a formal hearing before an administrative law judge. Your petition requesting a contested case hearing must include a statement of reasons or proposed findings supporting the MPCA decision to hold a contested case hearing pursuant to the criteria identified in Minn. R. 7000.1900, subp. 1 and a statement of the issues proposed to be addressed by a contested case hearing and the specific relief requested. To the extent known, your petition should include a proposed list of witnesses to be presented at the hearing, a proposed list of publications, references or studies to be introduced at the hearing, and an estimate of time required for you to present the matter at hearing. You must submit all comments, requests, and petitions during the public comment period identified on page 1 of this notice. All written comments, requests, and petitions received during the public comment period will be considered in the final decisions regarding the permit. If the MPCA does not receive any written comments, requests, or petitions during the public comment period, the Commissioner or other MPCA staff as authorized by the Commissioner will make the final decision concerning the draft permit. During the public comment period, however, you may request that the draft permit be presented to the

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MPCA’s Citizens’ Board (Board) for final decision. You may participate in the activities of the Board as provided in Minn. R. 7000.0650. Comments, petitions, and/or requests must be submitted by the last day of the public comment period to:

Scott Knowles, P. E. Minnesota Pollution Control Agency

525 S. Lake Ave, Ste. 400 Duluth, MN 55802

The permit will be issued/reissued/modified if the MPCA determines that the proposed Permittee or Permittees will, with respect to the facility or activity to be permitted, comply or undertake a schedule to achieve compliance with all applicable state and federal pollution control statutes and rules administered by the MPCA and the conditions of the permit and that all applicable requirements of Minn. Stat. ch. 116D and the rules promulgated thereunder have been fulfilled. More detail on all requirements placed on the facility may be found in the Permit document. Facility Description

Background Information Facility Location The Rahr Malting Co facility (Facility) is located at SE 1/4 of SW 1/4 of Section 1, Township 115 North, Range 23 West, Shakopee, Scott County, Minnesota. Outfall Location The topographic map in the draft permit shows the location of designated monitoring stations and outfalls on a US Geological Survey quad map. The “Summary of Stations” page in the draft permit specifies the designated monitoring stations and outfalls and their respective Public Land Survey coordinates.

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Maps of Permitted Facility

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Components and Treatment Technology Current Information The principal activity at this Facility is the conversion of barley to barley malt for use in brewing, distilling, and malting food industries. Approximately 2.5 million pounds of barley is converted into 2.1 million pounds of malt per day. The Facility has an annual production capacity of approximately 23 million bushels of malt. The noncontact cooling water discharge consists of untreated well water which is discharged to the Minnesota River at a design average and maximum rate of 1,500,000 gallons per day (gpd) and 3,500,000 gpd, respectively. The existing sequencing batch reactor (SBR) wastewater treatment plant (WWTP) was expanded utilizing a membrane bioreactor (MBR) system. The combined, and parallel, treatment trains (SBR & MBR) are designed to treat a peak hourly wet weather (PHWW) flow of 2.41 million gallons per day (MGD)[see the Updated Engineering Design Report, Rahr Malting Company, Wastewater Treatment Facility Phase II, revised November 2006; and the Rahr Malting Company Wastewater Treatment Plant Expansion and Koda Energy Biomass Combined Heat and Power Plant Environmental Assessment Worksheet (EAW), 2007]. The facility is further described/discussed in the draft permit facility description. Both the noncontact cooling water and the treated process wastewater are discharge to the Minnesota River. Sanitary wastes are discharge to the municipal sanitary sewer and are treated at the Blue Lake WWTP. Sludges generated at the facility will be handled pursuant to the MPCA’s Industrial By‐Product permit, SDS General Permit No. MNG960040.

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Flow Schematics

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Changes to Facility or Operation No significant changes have been made since construction/installation of the new MBR system. Recent Compliance History The last facility inspection was on 4/15/2008 (inspected membrane installation). No late DMRs or exceeded rates have been identified. The last pollutant trading inspection was on 9/13/2011. The pollutant trading sites were found to be in compliance with the requirements of the permit. Recent Monitoring History

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Receiving Water(s) Use Classification The discharge from Rahr Malting is located on the Minnesota River. The once in ten year weekly average flow (7Q10) at this location has been estimated to be 130.6 mgd (202 cfs). The receiving water is a Class 2B, 3C, 4A, 4B, 5, 6 water. The quality of class 2B waters shall be such as to permit the propagation and maintenance of a healthy community of cool or warm water sport or commercial fish and associated aquatic life, and their habitats. These waters shall be suitable for aquatic recreation of all kinds, including bathing. The quality of Class 3C waters of the state shall be such as to permit their use for industrial cooling and materials transport without a high degree of treatment being necessary to avoid severe fouling, corrosion, scaling, or other unsatisfactory conditions.

The quality of Class 4A waters of the state shall be such as to permit their use for irrigation without significant damage or adverse effects upon any crops or vegetation usually grown in the waters or area, including truck garden crops.

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The quality of Class 4B waters of the state shall be such as to permit their use by livestock and wildlife without inhibition or injurious effects.

The quality of Class 5 waters of the state shall be such as to be suitable for aesthetic enjoyment of scenery, to avoid any interference with navigation or damaging effects on property.

The uses to be protected in Class 6 waters may be under other jurisdictions and in other areas to which the waters of the state are tributary, and may include any or all of the uses listed in Minn. R. 7050.0221 to 7050.0225, plus any other possible beneficial uses. The agency, therefore, reserves the right to impose any standards necessary for the protection of this class, consistent with legal limitations.

Impairments The Minnesota River is listed on the 303(d) list of non‐attainment waters for Hg. The non‐attainment listing is based on fish consumption advice for mercury and water column exceedances of the water quality standard.

Existing Permit Effluent Limits Technology Based Effluent Limits (TBELs) Minn. R. ch. 7053 requires point source dischargers of industrial or other wastes to, at a minimum, comply with all applicable federal standards promulgated by the United States Environmental Protection Agency; derived from federal effluent limitation guidelines (ELGs). If effluent limitations for five‐day carbonaceous biochemical oxygen demand, total suspended solids, pH, or oil are not established under applicable federal standards for any point source discharger of industrial or other wastes, that point source discharger shall comply with the effluent limitations for those substances established in MInn. R. 7053.0215, subp. 1, or with such other equivalent mass limits established under Minn. R. 7053.0205, subp. 8, if applicable. TBELs for carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS), pH, and oil derived pursuant to Minn. R. ch. 7053 are developed for achieving secondary treatment standards. These concentration based limits include: CBOD5* 25 mg/L TSS* 30 mg/L Oil Essentially free of visible oil pH range 6.0 – 9.0 *The arithmetic mean for concentrations of five‐day carbonaceous biochemical oxygen demand and total suspended solids shall not exceed the stated values in any calendar month. In any calendar week, the arithmetic mean for concentrations of five‐day carbonaceous biochemical oxygen demand shall not exceed 40 milligrams per liter and total suspended solids shall not exceed 45 milligrams per liter. Pursuant to federal regulations, 40 CFR 122.45(f), TBEL mass limitations are derived as follows: CBOD5 : 25 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 312.75 #/d = 141.9 kg/d calendar month average 40 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 500.40 #/d = 227.0 kg/d calendar week average

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TSS : 30 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 375.30 #/d = 170.2 kg/d calendar month average 45 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 562.95 #/d = 255.4 kg/d calendar week average Pursuant to federal regulations, 40 CFR § 122.45, and Minn. R. 7053.0205 subp. 10; these mass limitations would be applied to the Rahr WWTP at the original (1997) design flow, and at the production capacity rating for the malt houses at that time (see 1997 permit, fact sheet, and permit application). Water Quality Based Effluent Limits (WQBELs) As discussed above Minn. R. ch. 7053 requires point source dischargers of industrial or other wastes to also comply with such other equivalent mass limitations established under Minn. R. 7053.0205, subp. 8 (WQBELs), if applicable. As documented in the 1996 Rahr fact sheet, the limitations established in the 1997 Rahr permit (in conjunction with the point‐nonpoint source trading) are, by definition, water quality based limits. Prior to issuance of the 1997 permit Rahr discharged all its process wastewater to the Blue Lake WWTP. Limits for the 1997 Rahr permit were based on the effluent concentration limits in the Blue Lake WWTP permit at that time, multiplied by the design flows for the new Rahr WWTP. Using the Blue Lake WWTP concentration limitations in existence in 1996, the mass effluent limitations for the Rahr WWTP were calculated as follows: CBOD5 : 12 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 150.0 #/d = 68.0 kg/d calendar month average 18 mg/L x 8.34 {(#/MG)/(mg/L)} x 2.5 mgd = 375.3 #/d = 170.2 kg/d peak day TSS : 30 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 375.30 #/d = 170.2 kg/d calendar month average 45 mg/L x 8.34 {(#/MG)/(mg/L)} x 2.5 mgd = 938.25 #/d = 425.6 kg/d peak day NH3‐N: 9 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 112.6 #/d = 51 kg/d calendar month average for May 12 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 150 #/d = 68 kg/d calendar month average for June 2 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 25.0 #/d = 11 kg/d calendar month average for July‐Sept. 5 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 62.6 #/d = 28 kg/d calendar month average for Oct. 7 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 87.6 #/d = 40 kg/d calendar month average for Nov. Dissolved Oxygen: 6 mg/L => April – Nov. when the flow @ Jordan < 20,000 cfs 7 mg/L => Dec. – Mar. when the flow @ Jordan < 20,000 cfs Total Phosphorus: 2 mg/L x 8.34 {(#/MG)/(mg/L)} x 1.5 mgd = 25 #/d = 11 kg/d calendar month average** **To enhance the originally proposed point‐nonpoint source trading that was required by the 1997 Rahr permit, Rahr Malting agreed to a total phosphorus (TP) concentration limit of 2.0 mg/L. The mass load allowed by the permit was calculated utilizing the new Rahr WWTP design flow, pursuant to that agreement. With the exception of the calendar month average CBOD5 mass limitation and calendar month average TP concentration limit (see discussion below on CBOD5 and TP) the draft permit retains the existing WQBELs limitations listed above. For further documentation, see non‐degradation section and trading attachments in the 1996 Rahr fact sheet.

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~ CBOD5 During the term of the 1997 permit, Rahr Malting was required to obtain 150 non‐point source load reduction units. By the fall of 1999, four non‐point source sites and five projects with associated Best Management Practices (BMPs) had been found, evaluated, approved, and constructed. The five projects exceeded the required 150 non‐point source load reduction units and resulted in a total of 212.8 non‐point source load reduction units. The proposed draft permit for the Rahr WWTP expansion gives credit to Rahr Malting for the 212.8 non‐point source load reduction units that were achieved as a result of the non‐point source load reduction projects. For further point‐nonpoint source trading information see attachment entitled “Point‐Nonpoint Source Trading Summary” below. ~ Total Phosphorus An effluent concentration limit of 1.0 milligrams per liter (mg/L) and influent monitoring for total phosphorus has been included in the draft permit, in accordance with the MPCA’s phosphorus strategy. The phosphorus strategy was developed and implemented due to widespread concern about the potential negative impacts of phosphorus on Minnesota's lakes, rivers, and streams. Phosphorus promotes algae and aquatic plant growth, often resulting in decreased water clarity and oxygen levels. In addition to creating general aesthetic problems, these conditions can also have negative impacts on the waters’ use for aquatic recreation, can produce unhealthy conditions for humans and animals, and can hinder the waters’ ability to support healthy fish and other aquatic species. For further documentation, see the “Effluent Limitations Summary” sheets dated June 28, 2007, June 4, 2007, and April 5, 2007. ~ Mercury (Hg) The Minnesota River is listed on the 303(d) list of non‐attainment waters for Hg. The non‐attainment

listing is based on fish consumption advice for mercury and water column exceedances of the water

quality standard. Effluent data has been collected for low level Hg from Rahr. A summary of the data

used to make the reasonable potential determination for Hg is documented in the “Effluent Limitations

Summary” sheets dated June 28, 2007, June 4, 2007, and May 22, 2007. The current average of all

mercury effluent data is 1.1 ng/l and the water quality standard (WQS) is 6.9 ng/l. The potential to

exceed WQBELs was made by using the maximum recorded effluent values to calculate the projected

effluent quality (PEQ), which was then compared to either the final acute value (FAV) or the daily

maximum WQBEL, whichever is more restrictive when applied to a Minnesota River. The PEQ value was

calculated to be less than the FAV or the daily maximum WQBEL, resulting in no WQBELs for Hg.

An increased loading of Hg in the discharge would trigger a non‐degradation review, unless Hg loading is held to current levels. It is believed that Hg is primarily associated with TSS in WWTP effluents. Rahr has chosen to freeze the loads for TSS. If the TSS load does not increase, it is believed that the Hg load will not increase due to this relationship. Therefore a non‐degradation review for Hg is not triggered. To verify existing conditions throughout the term of the next permit, effluent monitoring for total mercury is included in the draft permit in accordance with the MPCA’s mercury strategy.

Proposed Permit Effluent Limits Technology Based Effluent Limits No changes to the technology based effluent limitations have been made from the previous permit.

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Water Quality Based Limits ~ Mercury (Hg) Monitoring results of the effluent included 27 data points at a calculated CV of 0.3188. PEQ is derived as an upper bound value from the highest value measured (1.7 ng/l), and the determined variability (CV = 0.3188) and number of data points (27). The Preliminary Effluent Limit (PEL) calculation assumes that the background mercury concentration is at the WQS (6.9 ng/l) when the listed stream impairment is for fish consumption advice, and no local river water column analytical data exist. To assure that the discharge does not cause or contribute to a WQSs excursion for mercury impaired waters, the numeric WQS (6.9) is applied at the point of discharge for the mass balance equation for the subsequent preliminary effluent limit calculations. Where PEQ exceeds the PEL, there is reasonable potential to cause or contribute to a WQSs excursion. Since PEQ does not exceed the PEL in this case, reasonable potential to cause or contribute to an excursion above WQSs is not indicated. A WQBEL is not needed. The following table contains the inputs to the reasonable potential analysis for mercury. The analysis is made with effluent data that is expressed as total metal. This pollutant was evaluated on the basis of analytical measurements that made evident the need for a full determination. Where PEQs exceeds the PELs, a WQBEL is needed.

Parameter Hg (ng/L)

Max Measured Value 1.7

# data points 27

PEQ 1.87

Plant flow ADW (mgd) 2.41

Rec. water flow, 7Q10(mgd) 130.57531

Background Conc. 6.9

Continuous Std (cs) 6.90

164

ppm hard

Maximum Std (ms) 2400.00

164

ppm hard

Final Acute Value (FAV) 4900

288

ppm hard

Mass Balance ‐cs 6.90

Mass Balance ‐ms 132059.65

Coeff of Variation (CV) 0.32

Long Term Avg‐cs 6.04

Long Term Avg‐ms 67224.32

Preliminary Effl limits:

Daily Max 11.86

Monthly Ave (2x/month) 8.49

Reasonable Potential

PEQ>Daily max FALSE

PEQ> FAV FALSE

Final Reasonable Potential No

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*Mercury background assumed to be at the standard because of the statewide mercury Total Maximum Daily Load. Because of the large data set, the very low mercury concentration and the non detection for the sulfur additive being used at this facility; mercury monitoring is not included in the draft NPDES/SDS permit. ~ Whole Effluent Toxicity Several fish community surveys have been conducted in the vicinity of this discharge, including surveys immediately above and below the discharge point and a third survey several miles downstream of the discharge point. Fish community data indicates sufficient biological integrity above the discharge point, a significant reduction in biological integrity immediately below the discharge point and the third survey several miles downstream demonstrates a significant biological recovery. For this reason acute Whole Effluent Toxicity (WET) monitoring is included in the draft NPDES/SDS permit for this Facility. The permit includes acute WET testing because the ratio of the 7Q10 low flow of the receiving water compared to the Facility’s maximum flow (MDF) is greater than 20:1. Because this Facility has never performed WET testing before, this facility will perform four WETa tests during the first year (done on a quarterly basis); and annually thereafter. This Facility does not have a WET limit because reasonable potential has not been shown; however, this facility will have a monitoring threshold value of 0.9999 TUa. The 0.9999 TUa is a threshold value, not a WET limit. ~ Total Phosphorus The noncontact cooling water station SD001 has a MDF of 3.5 mgd; and consists of an intermittent discharge of non‐contact cooling water originating from onsite groundwater wells with no additional phosphorus‐containing chemical additives. Effluent from this outfall is likely to have a very low TP concentration (< 0.1 mg/L), and therefore, no additional limitations are required at this time. However, given the variability of phosphorus concentration in groundwater, this permit includes TP monitoring at outfall SD001 to determine if further permit requirements are necessary in the future. ~Additional Monitoring Requirements Pursuant to 40 CFR § 122.21(j) MPCA staff have determined that for industrial & other discharges (where reasonable potential may exist for the discharge of total Kjeldahl nitrogen (TKN), nitrite/nitrate nitrogen, total dissolved solids, total residual chlorine and/or other oxidants) addition monitoring for these compounds will be included in issued and reissued permits. Hence monitoring for these compounds is included in the draft permit (twice per year). No other changes to the water quality based effluent limitations have been made from the previous permit.

Additional Requirements Land Application of Industrial By‐Products & Biosolids Sludges generated at this facility will be handled pursuant to the general permit for food and beverage processing facilities, SDS General Permit No. MNG960040. These standards serve as the baseline requirements for all land application of industrial by‐products.

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Point‐Nonpoint Source Trading Summary For further point‐nonpoint source trading information see attachment entitled “Point‐Nonpoint Source Trading Summary” below.

Total Facility Requirements (TFR)

See Chapter 8 in the draft permit for the TFR.

Nondegredation and Anti‐Backsliding Antibacksliding The mass limits derived for the 1997 Rahr permit (in conjunction with the point‐nonpoint source trading) are, by definition, water quality based effluent limitations. The proposed draft permit for the Rahr WWTP expansion gives credit to Rahr Malting for the 212.8 non‐point source load reduction units that were achieved as a result of the non‐point source load reduction projects. Since all other limitations are being maintained, or are more restrictive, antibacksliding review is not triggered. For further point‐nonpoint source trading information see attachment entitled “Point‐Nonpoint Source Trading Summary” below. Nondegradation: Discharges to Non‐ORVWs This facility discharges to the Minnesota River, which is not designated as an Outstanding Resource Value Water (ORVW), therefore, the date of implementation of the nondegradation rules (January 1, 1988) applies to this facility. The January 1, 1988 design average wet weather/daily maximum flow for this facility was 0.0 MGD. In accordance with MPCA rules regarding nondegradation for all waters, the design average wet weather/daily maximum flow of the facility as of January 1, 1988, and associated mass loading serve as the baseline design flow and mass loading. This baseline flow and mass loading as of January 1, 1988 was used to determine whether nondegradation review was required for any change in the discharge. Any change that resulted in an increase in design flow greater than 0.2 MGD and an increased loading of one or more pollutants, or any change in a discharge containing a toxic pollutant that results in a mass loading rate likely to increase the concentration of the toxicant in the receiving water by greater than one percent over the baseline quality, was subject to nondegradation review in accordance with Minn. R. 7050.0185 in the preparation of this draft permit.

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Point‐Nonpoint Source Trading Summary Attachment

In 1996, Rahr Malting Company (Rahr) proposed to remove its process wastewater flow from the Metropolitan Council Environmental Services (MCES) Blue Lake wastewater treatment facility (Blue Lake). On January 8, 1997, Rahr was issued an NPDES permit to allow the discharge of up to 150 lb/day of CBOD5 directly to the Minnesota River. Prior to this, Rahr’s process wastewater was treated at Blue Lake, which also discharges directly to the Minnesota River. The Minnesota Pollution Control Agency (MPCA) has established the maximum allowable load that can be discharged into the lower 25 miles of the Minnesota River and has fully allocated available load capacity, primarily to two MCES facilities ‐ Blue Lake and Seneca. Rahr’s request for a permit to discharge was in addition to this current allocation. The MPCA requested that Rahr compensate for the additional 150 lb/day of CBOD5 load by reducing the load in other areas of the watershed. The effluent is mixed with Rahr’s non‐contact cooling water and discharged to the Minnesota River through the existing outfall. Rahr’s sanitary wastes continue to go to Blue Lake. The impact of Rahr’s relocated discharge will not occur until the allocated MCES capacity is reached and Rahr’s load to Blue Lake is replaced by another wastewater source. It was originally thought that this would happen in approximately ten years. The timing of this replacement loading provided Rahr with an opportunity to implement a program of non‐point source (NPS) load reduction that would have basin wide impact. It has now been more than ten years since the January 8, 1997, permit issuance and the two MCES wastewater treatment plants that discharge into the Minnesota River have not reached their capacity. During the initial five years of the permit, Rahr implemented a program of NPS load reduction to achieve the required reduction of 150 lb/day to offset the allowed discharge. Through five projects in four locations Rahr actually achieved a reduction of 212.8 lb/day. 62.8 lb/day more than required. It is this additional 62.8 lb/day NPS reduction that allowed Rahr to increase their discharge to the Minnesota River. It was agreed between the parties that since Rahr achieved reductions in excess of 150 lb/day, they would be credited with the additional reductions and be allowed to discharge up to that amount in the future.

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