Jump to main content.


Project XL Logo

Minnesota Pollution Control Agency (MPCA)

US Filter Proposal

U.S. Filter Recovery Services, Inc.
2430 Rose Place
Telephone 612-638-1300
Roseville, MN 55113
Facsimile 612-633-5074

March 6, 1996
Mr. Joseph P. Carruth Engineer,
Permit and Review Unit Regulatory Compliance Section Hazardous Waste Division
Minnesota Pollution Control Agency
520 Lafayette Road
St. Paul, MN 55155-3898

Dear Joe:

Enclosed is our revised Project XL Permit application. The changes we have made include:

Added estimated environmental impact numbers for both the acid recovery project and the water re-use project;

More detailed project descriptions (including basic schematics); and

Added proposed timing for project execution. As we discussed in our meeting, Project #2 "Product Stewardship/Life-cycle Management" was not changed.

We look forward to moving ahead with this project. If you have any questions or require further information, please contact Greg Weisjahn or me.

Yours truly,

Greg E. Norgaard, P.E. Vice President and General Manager GEN/ll

Enclosures

cc: Andrew Ronchak, MPCA Raymond Bissonnette,
MPCA Draft Beyond Compliance Permit U.S. Filter Recovery Services, Inc.

Background
"Beyond Compliance" is Minnesota's proposal to conduct a "State of Minnesota" project under the "Project XL" priority action item outlined in President Clinton's and Vice President Gore's March 16, 1995, document titled, Reinventing Environmental Regulation and noticed in the May 23, 1995 Federal Register. "Beyond Compliance" provides an exciting opportunity to change the way we conduct our business, resulting in a " cleaner, cheaper, and smarter" approach to environmental regulation. This innovative approach will be beneficial for the following reasons:

Environmental Results
Cost Savings and Paperwork Reduction
Stakeholder Support
Innovative/Multi-Media Pollution Prevention
Transferability
Feasibility
Monitoring, Reporting, and Evaluation

The incentive for a company to participate in "Beyond Compliance" would primarily be increased operating flexibility in adding storage or process equipment. The regulatory flexibility will result in resource savings and ability to quickly react to changing market conditions. The resource savings would result in less paperwork requirement, through combining and streamlining regulations. Secondly, resource savings would result from eliminating the need for obtaining permit modifications. Another benefit of this approach would be to give the company the flexibility to determine how to best implement changes at the source without increasing environmental pollution above an agreed-upon limit.

As a result of less regulatory oversight and the streamlining of procedures, the MPCA and EPA would save resources while obtaining a significant improvement in the quality of the environment. The primary source savings would be in elimination of previously required reviews and actions on reports and applications. Assuming success in the early pilots, as the "Beyond Compliance" multi-media approach is used on a larger scale, the MPCA and EPA should also begin to see resource savings through the combining of overlapping programs.

U.S. Filter Recovery Service's "Beyond Compliance" permit will focus on incorporating the "Beyond Compliance" philosophy into their RCRA Part B Permit, with the intent of reducing the amount of chemicals purchased and to facilitate the recovery of chemicals for all parties within the bubble of the pilot project.

Pursuant to the provisions of the MPCA "Beyond Compliance Pilot Program" granted under the authority of the EPA, permission is hereby granted to:

U.S. Filter Recovery Services, Inc.
2430 Rose Place
Roseville, MN 55113

for participating in MPCA's "Beyond Compliance" program. While the pilot project is in effect, MPCA enforcement action will not be taken against persons who manage hazardous waste in compliance with the specified pilot project requirements, even though persons may not be in compliance with the hazardous waste management requirements in Minn. Rules ch. 7045. Hazardous waste not managed in compliance with the pilot project must be managed in accordance with all applicable hazardous waste management requirements in Minn. Rules ch. 7045.

Concepts used by USFRS in "Beyond Compliance" include: product stewardship, product life-cycle management, and eco-industrial park to facilitate a reduction in chemical purchases and to maximize the recovery of chemicals. By employing these concepts this allows companies other than USFRS using these chemicals to indirectly participate in the "Beyond Compliance" program. With this indirect involvement of other companies, this will make "Beyond Compliance" more accessible to companies and make participation available for small business.

Project #1

RCRA Permit Flexibility for Recovery Projects

Introduction
USFRS would like to have the ability to implement RCRA-regulated activities associated with new recycling operations without having to go through a "major" permit modification. In return, USFRS will:

1. Pursue only those projects under this project which show measurable, definable recovery.
2. Comply with all applicable hazardous waste regulations including:

Basic Tank/Process Design
Secondary Containment
Inspection of Treatment/Recovery/Storage Areas
Compatibility
Aisle Space

3. Remain subject to all other current enforcement authority over all aspects of the operation, regardless of "Beyond Compliance" permit status.
4. Incorporate any modifications into the RCRA permit at the next renewal.

Specific Projects

1. Acid Recovery:
USFRS hereby requests the authority to install and operate a hydrochloric acid recovery system under Project XL. The technology employed is vacuum distillation and is described in Appendix A. Inbound waste acid (D002 hazardous waste) destined for recycling would be stored in one of two 6,000 gallon storage tanks and then routed to the recovery system. Under ordinary circumstances, the waste acid storage tanks would require a major modification to our Part B Permit. We are requested that these tanks be considered under Project XL, incorporating the stipulations indicated above. Additionally, to encourage generator participation in Project XL, participants should be subject to a lesser level of regulation for these specific recovery streams under the pilot program. USFRS will provide the waste tracking data to the agency as a part of the verification process.

Benefits to USFRS
Time: major permit modifications take a long time until completion
Staff time: the time it takes to modify the permit is significant
Fees: it costs approximately $12,000 to do a major modification
Benefits to the Environment
Reduced "importation" and usage of virgin HC1 (due to recovery)
Reduced usage of neutralization chemicals
Closed loop system (metals, acid and water are all recovered)
Lower acid concentration for safer transport and handling
Reduced discharge to the POTW (hydraulic, metal and salt)
Pollution prevention is available even to the smallest generator
Sufficient regulatory control is still maintained
Estimated Environmental Impact If the system is operated at full capacity (250 gph, 7 days/wk., 24 hrs./day, 10% downtime), the following environmental impact could be expected:
Recover 1.54 million pounds of HC1/year
Save 498,800 gal/year of purchased acid (20 degree Be' HC1)
Save 1.69 million pounds/year of purchased neutralization chemical
Recover 263,000 pounds/year of heavy metal
Prevent 2.72 million lbs/year of salt from being sewered
Recover 883,000 gal/year of distilled water
Verification of Beyond Compliance
Results The success of this project would be gauged by
USFRS tracking and reporting the following data:
Pounds of recovered material and quality
Volume of incoming waste
Estimate of cost and time savings in permit modifications

Project Timing
USFRS proposes to install and commence operating the proposed storage tanks on or before July 1, 1996.

2. Water Re-use
USFRS hereby requests the authority to install and operate the equipment necessary to regenerate spent ion exchange resins used for water re-use. These resins are typically classified as F006 hazardous waste. Under its existing permit, USFRS operates a large regeneration pad, currently processing several thousand cubic feet/month strictly for metals and cyanide removal/recovery. The proposed system would expand these capabilities to enable our clients to use ion exchange technology to re-use water from "hazardous waste" rinsing operations. The system is described more thoroughly in Appendix B. Under ordinary circumstances, the systems to store and regenerate these resins would require a major modification to our Part B Permit. We are requesting that this system be considered under Project XL, incorporating the stipulations indicated above. Additionally, to encourage generator participation in Project XL, participants should be subject to a lesser level of regulation for these specific recovery streams under the pilot program. USFRS will provide the waste tracking data to the agency as a part of the verification process.

Benefits to USFRS
Time: major permit modifications take a long time until completion
Staff time: the time it takes to modify the permit is significant
Fees: it costs approximately $12,000 to do a major modification
Benefits to the Environment
Total amount of water consumed by water re-use clients is significantly reduced.
Total amount of wastewater discharged by water re-use clients is significantly reduced.
Total cation resin usage (therefore hazardous waste generation) is reduced significantly due to elimination of water hardness (calcium) in reused stream
Total hazardous waste generation from the regeneration process is reduced significantly due to the elimination of calcium hardness
The recycled water is generally of higher quality (better rinsing, fewer rejects, therefore less waste)
Large reduction in salt load to POTW
Pollution prevention is available even to the smallest generator
Sufficient regulatory control is still maintained
Estimated Environmental Impact
If the system is operated at full proposed capacity and the average client is able to reuse 80% of their water (influent water at 18 grains total hardness), the following environmental impact could be expected:
Reduce sewer discharge by 31.4 million gal/year
Reduce water usage by 31.4 million gal/year
Reduce hazardous waste generation (cation resin) by 630,000 pounds/year
Prevent 151.400 lbs/year of salt from being sewered
Verification of Beyond Compliance Results
The success of this project would be gauged by USFRS tracking and reporting the following data:
Volume of inbound water re-use resin
Estimate of water savings, sewer savings, hazardous waste reduction and salt discharge reduction
Estimate of cost and time savings in permit modifications

Project Timing
USFRS proposes to install and commence operating the proposed storage tanks on or before July 1, 1996.

Project #2

Product Stewardship
Life-cycle Management Product stewardship is the second project USFRS proposes for the pilot project. This project would include ammoniacal and cupric chloride etchants and other similar chemicals that USFRS can manage the life-cycle of the product. These etchants are managed as by-products; however, the paperwork involved to manage these materials is as cumbersome as manifesting hazardous waste. USFRS proposed to take on the responsibility of tracking these wastes and reporting to MPCA the amount received from each generator. USFRS would have blanket approval of all material that fits into the product stewardship program. For example, the MPCA would approve that ammoniacal etchants and their management by USFRS fit into the product stewardship category and that USFRS can manage all ammoniacal etchants under this program. This would reduce the paperwork for the generator, USFRS, and the state. USFRS will comply with the following hazardous waste regulations:

Basic Tank/Process Design
Secondary Containment
Inspection of Treatment/Recovery/Storage Areas
Compatibility
Aisle Space

MCPA will maintain its existing enforcement authority over all aspects of the operation, regardless of "Beyond Compliance" permit status. In addition, any modification will become part of the RCRA permit at the next renewal.

Benefits to USFRS

1. Paperwork reduction
2. Increased recycling
3. Uniformity in handling inbound waste products

Benefits to Environment

1. Encourage recycling (compared to existing system)
2. Assured proper management of chemicals throughout their life-cycle
3. Paperwork reduction
4. Pollution prevention is available even to the smallest generator
5. Minimize metals discharged to sewer
6. Eliminate treatment chemicals used by clients
7. Copper and ammonia are recovered

Verification

1. Documentation of recovery, track pounds of recovered material and quality
2. Track volume of incoming waste
3. Compare data between amount recovered to amount of waste generation
4. Track chemical savings due to beneficial recycling

Note reduction in virgin chemical purchases
Note reduction in treatment chemical purchases

5. Track the cost savings due to recovery

6. Track the cost savings in permitting and regulatory compliance

APPENDIX A
ACID RECOVERY SYSTEM DESCRIPTION
A. PROGRAM DESCRIPTION Hydrochloric acid use and waste generation in the metal finishing industry : Hydrochloric acid (HC1) is used in the electroplating and metal finishing industries as a "pickling" liquid. That is, as a preparatory treatment to various metal plating and conversion coating processes. It is usually made up at 16-20% (by weight) strength, and a process bath will last anywhere from 2-10 weeks. During the life of the pickling bath, metal ions from the parts are etched or dissociate from the base metals. Thus the bath ends up with part per million to part per thousand levels of iron, zinc and various other toxic metals, and 50-75% of the starting HC1 levels.

Historically, once a pickling bath was "spent", it was typically treated in a batch-wise process where alkalinity is added (usually sodium hydroxide (NaOH)) to increase the pH and precipitate the metals as metal hydroxide and metal oxides. The metal sludges are then filtered out of the alkaline wastewater, the pH is adjusted to discharge standards, and the sludge is sent for stabilization and landfilling. A significant amount of salt (sodium chloride) is formed during neutralization and is discharged to the sewer.

The remaining acidity in the bath, some 50-75% of the initial bath make-up is wasted by the required neutralization, never to be recovered. The metal sludges may also end up in a landfill, instead of feeding a recovery process which utilizes them again. In addition, the generator must purchase and handle the NaOH for neutralization, and also the fresh acid to make up the new pickling bath. These baths are sources of high metals loads to the waste treatment systems, and create potential metals discharge difficulties for the generator.

If some method could be implemented whereby the acid could be recovered, much discharge to the sewer system and chemicals usage could be reduced. If the metals in the wastes could also be more effectively handled in this new process, even more pollution could be prevented.

Innovation, Industry Partnerships and Project Initiation:

The concept of an attempt to recover this waste HC1 was first discussed by U.S. Filter and several of its metal finishing "founders" in the spring of 1994. At that time, USFRS had been operating its copper etchant recovery process for over a year with great environmental and economic success. The local metal finishing industry knew that it was neutralizing and discharging millions of pounds of hydrochloric acid each year, and that the technology to recover the acid was too expensive and complex for any single metal finisher to implement alone. Led by Denny Donaldson, President of NICO, they asked USFRS to evaluate the potential technologies to accomplish recovery of this spent acid.

As mentioned in the Company Background section, USFRS is the CTRF for the local metals industry. As such, it can leverage technology and capital investment across many company's waste volumes, and thus provide new approaches and capabilities that no single company could individually. This cooperation with local industry is one of the primary keys to USFRS's success. So, a request like the one made in 1994 was not unusual, but actually typical of the 8+ year working relationship.

After extensive technical investigations and thorough economic evaluations, it was decided to recover the waste hydrochloric acid via vacuum distillation. Although never attempted on this scale before, this innovative approach had the advantages of recovery of two streams (HC1 and water), and leaving a metals rich remainder for further recovery at the facility. It also reduced the need for process water, and could be used to recover USFRS's own HC1 streams that come from our ion exchange resin regeneration process.

Outreach methods employed to promote and achieve the significant acid recovery and metal reclamation include a press release, a 15 minute video (included with this application), various brochures, and numerous facility tours and training sessions (some attended by MPCA staff members).

System and process description:

(Note: A Process Flow Sheet is included in the attachments.) The hydrochloric acid recovery system is constructed of completely non-metallic materials.
The process consists of reboiler, vacuum distillation column, reflux and cooling condensers, and associated plumbing and tanks. It is computer controlled via a central control panel for ease of operation. It is unique in the U.S., and the only commercial scale HC1 vacuum distillation system in the world.

The process flow is as follows:

Waste acid is pumped through activated carbon filters to remove trace organics.
If the waste acid is high in sulfates, phosphoric acid is added to control scaling on the reboiler heating surfaces.
The waste is then introduced into the reboiler loop, where it is heated, under vacuum (125 mm Hg absolute) to the boiling point.
Water and HC1 vapors the travel up the column, which is packed with an inert material which aids the separation.
At a point about 75% up the column, the pure 18-20% hydrochloric acid is pumped off through a cooler and into fresh acid storage.
The distilled water vapor exits the top of the column, where it is condensed. Some is returned as liquid to the top of the column (reflux), and some is further cooled and pumped to clean water storage.
The concentrated undistilled liquids are periodically removed from the reboiler loop and the metals recovered elsewhere in the USFRS plant.
The repurified acid is sold back to the metal finishers, in bulk tank truck loads, 330 gallon totes or 55 gallon drums.
The distilled water is used for various rinsing operations in other recovery processes elsewhere in the plant, which is part of our overall water use reduction program.

APPENDIX B
WATER RE-USE SYSTEM DESCRIPTION
Appendix B: Ion Exchange Regeneration Systems for RCRA Hazardous Waste Water Re-Use Resin

Ion exchange for water re-use is similar to ion exchange used to treat rinse water for discharge. The main difference is that ion exchange used for re-use consists of both cation and anion resins to purify the rinse water for return to the process. By contrast, only cation resin is needed to remove regulated metals from the rinse water so that it can be sewered in compliance with discharge regulations. Separate canisters of cation and anion resins are used for water reuse; however, it is more common to use mixed bed resins. As the name implies, mixed bed canisters contain a mixture of cation and anion resin in the same canister. This fact improves the purity of water treated by the canister and, at the same time, complicates the regeneration process since the mixed resin must first be separated. Referring to the process flow diagram, canisters of spent mixed and separate bed ion exchange resins are brought to the U.S. Filter Recovery Services facility. Most of these spent resins are considered RCRA hazardous wastes because they are pretreatment residuals (F006) or fail the TCLP for one or more RCRA metals (the D-code wastes, e.g. chromium, D007).

Separate resins are removed from the canisters and put into hoppers for storage. Mixed bed resins are removed from canisters and placed into the mixed separation vessel. Back washing the resin separates the resins by gravity, heavier cation resins settling in the bottom of the vessel and lighter anion resin above. From the separator or the hoppers, the resins are sent to the cation and anion regeneration vessels for treatment. Acid is used to regenerate the cation resin and caustic soda for the anion resin. Water is used to rinse the resins and then the resins are sent to regenerated anion and cation resins hoppers or the mixed bed resin mixing vessel where the regenerated cation and anion resins are re-mixed. The final step in the process returns the regenerated resin to canisters for return transportation to clients.

Acid and caustic soda used for resin regeneration contains the RCRA regulated metals or carry the F006 listing and so must be dealt with as RCRA wastes. These regenerants are handled in USFRS processes for metal and acid recovery.


Local Navigation


Jump to main content.