CALDERWOOD & HARKNESS LLP Attorneys at Law 801 Grand Avenue, Suite 4400 Des Moines, Iowa 50309
May 5, 2023
Ms. Amy Lindstrom Environmental Specialist Senior Water Quality Bureau Iowa Department of Natural Resources 502 East 9th Street Des Moines, Iowa 50319
Re: Application for National Pollutant Discharge Elimination System (NPDES) Individual Permit — Muscatine Expansion Facility, 14800 Highway 61 North, Muscatine, Iowa 52761
Applicant: Greenfield Agricultural Partners LLC
C&H Matter No.: 1020-00004
Dear Ms. Lindstrom:
Purpose and Authorization
Calderwood & Harkness LLP represents Greenfield Agricultural Partners LLC ("GAP"), an Iowa limited liability company (Iowa Secretary of State Filing No. 548213; EIN 46-3827194), in connection with environmental permitting for GAP's planned Muscatine Expansion Facility (the "MEF" or "Facility"). Pursuant to this representation, and as duly authorized by GAP, Calderwood & Harkness LLP ("C&H") is submitting on behalf of GAP the enclosed application for a National Pollutant Discharge Elimination System ("NPDES") Individual Permit under the Iowa Administrative Code 567—Chapter 64 and Section 402 of the federal Clean Water Act, 33 U.S.C. § 1342. The application seeks authorization to discharge treated process wastewater and industrial stormwater from the MEF to waters of the state, as more fully described below.
We respectfully request that the Water Quality Bureau review this application and process it in due course. The enclosed materials have been assembled to provide a comprehensive submission that addresses each of the informational requirements set forth in the applicable regulations and IDNR guidance documents. Should the Bureau determine that any additional information is necessary to complete its review, we are prepared to respond promptly.
Description of Applicant and Facility
GAP is headquartered at 4200 Prairie Wind Drive, Suite 300, West Des Moines, Iowa 50266. GAP currently operates three existing soybean crush facilities located in Iowa and Nebraska and distributes specialty fertilizer products across the upper Midwest. In its most recently completed fiscal year (2022), GAP generated revenues of approximately $485 million. GAP is a well-established participant in the agricultural processing sector, with an experienced management team and a demonstrated history of environmental compliance at its existing operations.
The MEF is a new greenfield soybean processing and specialty fertilizer blending facility to be constructed on a 147-acre site located at 14800 Highway 61 North, Muscatine, Iowa 52761, in Muscatine County (Muscatine County Parcel ID 0735-19-200-004). GAP acquired the site from the Reinholt Family Trust on January 20, 2023; title services in connection with the acquisition were provided by Hawkeye Title & Escrow LLC. The site is currently unimproved agricultural land, and no prior industrial operations have been conducted on the parcel.
The Facility is designed to add 3,200 tons per day of soybean crush capacity and a 450-ton-per-day granular fertilizer blending line. Upon completion of construction and commissioning, the MEF will represent a significant expansion of GAP's processing capacity and will serve the growing demand for soybean-derived products and specialty fertilizer blends throughout the upper Midwest.
The site is zoned Agricultural-Industrial (AI) under the Muscatine County zoning ordinance. A conditional use permit (CUP No. MC-2022-041) was approved by the Muscatine County Board of Supervisors on November 15, 2022, providing local land-use approval for the construction and operation of the Facility at this location. A copy of the approved conditional use permit is included among the enclosed documents.
Description of Proposed Discharges
The application seeks authorization for two discharge outfalls, as described below.
Outfall 001 — Treated Process Wastewater
Outfall 001 will convey treated process wastewater generated by the soybean processing and fertilizer blending operations at the MEF. The primary sources contributing to this outfall include soybean wash water generated during the initial cleaning and preparation stages of the crush process and cooling tower blowdown from the facility's closed-loop cooling water systems. The design flow for Outfall 001 is 0.38 million gallons per day (MGD). The discharge from Outfall 001 will be continuous during facility operations, subject to normal operational fluctuations.
Outfall 002 — Industrial Stormwater
Outfall 002 will convey industrial stormwater runoff from the developed portions of the Facility site. The sources contributing to Outfall 002 include stormwater runoff from paved areas within the facility complex, the fertilizer loadout pad, and the truck wash facility. The discharge from Outfall 002 will be intermittent and precipitation-dependent, occurring only during and following rainfall or snowmelt events that generate runoff from these impervious surfaces.
Receiving Water. Both Outfall 001 and Outfall 002 discharge to Sweetland Creek, a tributary of the Mississippi River. The outfall locations are identified on the site maps enclosed with this application. Sweetland Creek is classified by the IDNR for the following designated uses: Class A1 (Primary Contact Recreation) and Class B(WW) (Warm Water Aquatic Life). The proposed discharge is designed and will be managed to be protective of these classified uses, as demonstrated in the application narrative and supporting technical materials.
Treatment System Summary
GAP has engaged Ridgeline Engineering Group LLC to design a treatment system for the process wastewater discharged through Outfall 001. The proposed treatment system consists of the following components, arranged in series:
1. Equalization Basin. An equalization basin designed to attenuate flow and loading variations inherent in batch soybean processing operations, thereby providing a consistent influent to downstream treatment units.
2. Dissolved Air Flotation (DAF) Unit. A dissolved air flotation unit designed to remove suspended solids, oils, and greases from the equalized wastewater stream prior to biological treatment.
3. Three-Cell Aerated Lagoon. A three-cell aerated lagoon system with a total surface area of 4.2 acres and an 18-day hydraulic retention time. The aerated lagoon system provides biological treatment for the removal of biochemical oxygen demand (BOD), ammonia nitrogen, and additional suspended solids.
4. Ultraviolet (UV) Disinfection. An ultraviolet disinfection system positioned immediately upstream of the discharge point to provide pathogen reduction prior to discharge to Sweetland Creek.
The treatment system is designed to achieve the proposed effluent limits set forth in the application narrative and summarized below. Detailed treatment system design descriptions, process flow diagrams, and design calculations are provided in the materials prepared by Ridgeline Engineering Group LLC, which are enclosed with this application.
Proposed Effluent Limits (Outfall 001)
The following table presents the proposed effluent limits for Outfall 001 that GAP believes are consistent with applicable technology-based and water-quality-based requirements under the NPDES program:
These proposed limits are supported by the effluent limit calculations and the process wastewater characterization data included in the enclosed application materials. GAP recognizes that the final permit limits will be established by the Bureau based on its independent review of applicable effluent limitation guidelines, water quality standards, and the results of any reasonable potential analysis.
Antidegradation Review
The enclosed application includes an antidegradation review discussion prepared in accordance with Iowa Administrative Code 567—61.2(2) and applicable IDNR guidance. GAP's preliminary assessment concludes that the proposed discharge qualifies for Tier 1 review, under which the analysis demonstrates that existing uses of Sweetland Creek will be maintained and protected. Based on this assessment, GAP has determined that no Tier 2 alternatives analysis is required. GAP's antidegradation analysis is consistent with the framework set forth in IDNR's antidegradation implementation procedures, and the supporting documentation is provided in the enclosed materials. GAP understands that the Bureau will conduct its own antidegradation review as part of the permit evaluation process and stands ready to provide any additional information the Bureau may need to complete that review.
Stormwater Pollution Prevention Plan (SWPPP)
The application includes a Stormwater Pollution Prevention Plan (SWPPP) for Outfall 002, prepared by Pinnacle Environmental Consultants Inc. The SWPPP addresses best management practices (BMPs) for the control and treatment of stormwater runoff from paved areas, the fertilizer loadout pad, and the truck wash facility. The BMPs identified in the SWPPP are designed to minimize the potential for pollutant transport via stormwater and to protect the water quality of Sweetland Creek. The SWPPP includes provisions for routine inspections, monitoring, recordkeeping, and corrective actions, as required under the applicable NPDES stormwater regulations.
List of Enclosures
The following documents and items are enclosed with this cover letter for the Bureau's review:
1. NPDES Permit Application Narrative (prepared by Calderwood & Harkness LLP).
2. Completed IDNR Form 1 and Form 2C (Industrial Wastewater Discharge Application).
3. Process wastewater characterization data and mass-balance analysis.
4. Treatment system design description and process flow diagrams (prepared by Ridgeline Engineering Group LLC).
5. Proposed effluent limits table with supporting calculations.
6. Antidegradation review discussion.
7. Stormwater Pollution Prevention Plan (SWPPP) (prepared by Pinnacle Environmental Consultants Inc.).
8. Site maps, including facility layout, outfall locations, and receiving water identification.
9. Copy of Muscatine County Conditional Use Permit No. MC-2022-041 (approved November 15, 2022).
10. Check in the amount of $3,600.00 payable to the Iowa Department of Natural Resources (NPDES Permit Application Fee).
Technical Support Acknowledgment
We wish to acknowledge the contributions of the technical consultants who prepared the scientific and engineering components of this application. The process wastewater characterization studies and the Stormwater Pollution Prevention Plan (SWPPP) were prepared by Pinnacle Environmental Consultants Inc., located at 1120 Ingersoll Avenue, Suite 210, Des Moines, Iowa 50309, under the direction of Karen Ott, Senior Water Quality Scientist. The treatment system design, process flow diagrams, and mass-balance data were prepared by Ridgeline Engineering Group LLC, located at 7700 Pioneers Boulevard, Suite 105, Lincoln, Nebraska 68506, under the direction of Thomas Novak, P.E., Project Manager.
Calderwood & Harkness LLP coordinated with both Pinnacle Environmental Consultants Inc. and Ridgeline Engineering Group LLC in preparing and assembling the application materials. However, C&H did not direct the technical work of either firm, and each firm is independently responsible for the accuracy and professional adequacy of its respective work product.
Filing Fee
The enclosed check in the amount of $3,600.00, made payable to the Iowa Department of Natural Resources, represents the NPDES Individual Permit application fee required under Iowa Administrative Code 567—Chapter 64. We request confirmation of receipt of the fee at the Bureau's earliest convenience.
Companion Air Permit Application
We note for the Bureau's awareness that on April 28, 2023, C&H filed on behalf of GAP a Prevention of Significant Deterioration (PSD) Construction Permit application with the IDNR Air Quality Bureau for the same Muscatine Expansion Facility. The air quality and water quality permit applications are being pursued on parallel timelines to support GAP's planned construction schedule. We mention this companion filing in the interest of inter-bureau coordination and to provide the Water Quality Bureau with a complete picture of the regulatory approvals being sought for the MEF.
Contact Information and Request
We respectfully request that the IDNR direct any questions, requests for additional information, or other correspondence regarding this application to the following individuals at Calderwood & Harkness LLP:
Rafael Dominguez, Lead Associate Calderwood & Harkness LLP 801 Grand Avenue, Suite 4400 Des Moines, Iowa 50309 Telephone: (515) 284-7300
Email: r.dominguez@calderwoodharkness.com
Cynthia Ho, Working Associate (copy) Calderwood & Harkness LLP 801 Grand Avenue, Suite 4400 Des Moines, Iowa 50309 Telephone: (515) 284-7315
Email: c.ho@calderwoodharkness.com
For questions that are facility-specific or operational in nature, the Bureau may also contact the following representatives of GAP directly:
Derek Yun, Director of Environmental, Health & Safety Greenfield Agricultural Partners LLC 4200 Prairie Wind Drive, Suite 300 West Des Moines, Iowa 50266
Margaret Solberg, Vice President of Operations / Muscatine Project Lead Greenfield Agricultural Partners LLC 4200 Prairie Wind Drive, Suite 300 West Des Moines, Iowa 50266
GAP is committed to the environmental integrity of the Muscatine Expansion Facility and desires an expeditious review of this application so that it may proceed with construction on its planned timeline. GAP and its representatives are fully prepared and willing to provide any supplemental information, clarifications, or additional technical data that the Water Quality Bureau may require in the course of its review. We welcome the opportunity to meet with Bureau staff at any time to discuss the application or address any questions that may arise.
Closing
Thank you for your attention to this matter, Ms. Lindstrom. We appreciate the Bureau's diligent review of NPDES applications and look forward to working with you and your colleagues through the permitting process.
Very truly yours,
CALDERWOOD & HARKNESS LLP
By: ________
Rafael Dominguez Lead Associate 801 Grand Avenue, Suite 4400 Des Moines, Iowa 50309
cc:
Patricia Caldwell, General Counsel & VP of Regulatory Affairs, Greenfield Agricultural Partners LLC Derek Yun, Director of Environmental, Health & Safety, Greenfield Agricultural Partners LLC Margaret Solberg, Vice President of Operations, Greenfield Agricultural Partners LLC James Prentice, Partner, Calderwood & Harkness LLP Sandra Tung, Partner, Calderwood & Harkness LLP Dr. Leonard Fisk, P.E., Principal, Pinnacle Environmental Consultants Inc. Karen Ott, Senior Water Quality Scientist, Pinnacle Environmental Consultants Inc. Thomas Novak, P.E., Project Manager, Ridgeline Engineering Group LLC
Enclosures (10) — as enumerated above
| Parameter | Monthly Average | Daily Maximum |
| BOD₅ | 30 mg/L | 45 mg/L |
| Total Suspended Solids (TSS) | 30 mg/L | 45 mg/L |
| pH | 6.5 – 9.0 (instantaneous range) | 6.5 – 9.0 (instantaneous range) |
| Ammonia Nitrogen (NH₃-N), April – October | 3.5 mg/L | — |
| Ammonia Nitrogen (NH₃-N), November – March | 8.0 mg/L | — |
| Total Phosphorus | 1.0 mg/L | — |
| Oil & Grease | — | 10 mg/L |
| Fecal Coliform | 200 CFU/100 mL (monthly geometric mean) | — |