NJ Waste Reduction Metal Finish
PUBL-SW-146 91
Background
There are over 31,000 metal finishing facilities in the United States and approximately 1,100 in New Jersey. Even when they vary in size, age and types of operations, they all generate hazardous waste from the production processes. Reducing the generation of hazardous waste can save you money and decrease your future liabilities!
Typical wastes generated in the metal finishing industry are:
- Industrial wastewater and treatment residue/sludge.
- Spent plating and stripping bath solutions.
- Spent process batch solutions.
- Spent acid and alkaline cleaners.
- Waste solvents, solvent still bottoms and oils.
- Metal dust, grindings and cuttings.
This fact sheet identifies areas for reducing waste generation. It also suggests techniques available to metal finishers for waste reduction and is intended to help metal finishing shop owners decide whether waste reduction is a possibility. For more information on waste reduction in fabricated metal manufacturing and metal finishing shops, contact the Hazardous Waste Advisement Program at (609) 292-8341.
Waste Reduction
New Jersey state regulations (N.J.A.C. 7:26-7.4(g)) require that generators of hazardous waste file an Annual Generator's Report. Among other requirements, this report must include a description of the efforts undertaken, and achievements accomplished, during the reporting period to reduce the volume and toxicity of waste generated.
The Uniform Hazardous Waste Manifest requires fully regulated generators to certify that they "have a program in place to reduce the volume and toxicity of waste generated... determined to be economically practicable" and that they have selected the "practicable method of treatment, storage, or disposal currently available... which minimizes the present and future threat to human health and the environment".
Since waste reduction methods help reduce the amount of waste generated, and also the amount of waste subject to regulation, these practices can help business comply with the requirements and save money. The following is a list of some common waste reduction practices for metal finishing shops:
- New Jersey Department of Environmental Protection
- Division of Hazardous Waste Advisement Program
- Hazardous Waste Advisement Program
- Bureau of Regulation and Classification
Beginning Your Waste Reduction Program:
- The shop's owner or manager must be committed to waste reduction and pass the commitment on to the employees.
- Establish training for employees in waste reduction along with hazardous material handling and emergency response.
- Establish incentive programs to encourage employees to design and use new waste reduction ideas.
Assess Hazardous Waste
Waste minimization assessments are essential to identify the sources, types and amounts of hazardous waste generated to make it easier to recommend where and how wastes can be reduced.
Source Reduction
Source reduction is usually the least expensive approach to minimizing waste. Many of these techniques involve housekeeping changes or minor in-plant process modifications.
Improve Procedures and Segregate Wastes
- Good housekeeping is the easiest and often the cheapest way to reduce waste. Keep work areas clean.
- Improve inventory procedures to reduce the amount of off-specification materials generated.
- Reduce quantities of raw materials to levels where materials will be used up just as new materials are arriving.
- Use a "first-in, first-out" policy for raw materials to keep them from becoming too old to be used. Give one person responsibility for maintaining and distributing raw materials.
- Designate raw material and hazardous waste storage areas and protect with spill containment provisions. Keep the areas clean and organized and give one person the responsibility for maintaining the areas.
- Label containers as required and cover them to prevent contact with rainfall and avoid spills.
- Use bench-scale testing for samples rather than in process baths.
- Designate one person to accept chemical samples and return unused samples to suppliers.
- Limit bath mixing to trained personnel.
- Segregate waste streams for recycling and treatment, and keep non-hazardous material from becoming contaminated.
- Prevent and contain spills and leaks by installing drip trays and splash guards around processing equipment.
- Conduct periodic inspections of tanks, tank liners, and other equipment to avoid failures. Repair malfunctions when they are discovered. Use inspection logs to follow up on repairs.
- Inspect plating racks for loose insulation that would cause increased drag-out.
- Use dry cleanup where possible to reduce the volume of wastewater.
Material Substitution
- Use processing methods which generate treatable or recyclable waste on-site.
- Use deionized water instead of tap water in process baths and/or rinsing operations to reduce sludge generated.
- Use non-chelated process chemistry rather than chelated chemistry to reduce sludge volume.
- Replace cyanide process with non-cyanide process such as carbonitriding or carbonizing to simplify treatment required.
- Use alkaline cleaners instead of solvents for degreasing operations. They can be treated on-site and usually discharged to the sewer with permit authorization.
Extending Process Bath Life
- Treatment (Filtration, Electrolytic Dummying, etc.) of process batch can extend their useful life.
- Bath replenishment extends the useful life of the bath.
- Monitoring (using Ph meters or conductivity meters) the process baths can determine the need for bath replenishment.
Drag-Out Reduction
- Minimize bath concentrations to the lower end of their operating range.
- Maximize bath operating temperatures to lower the solution's viscosity.
- Use wetting agents (which reduce the surface tension of the solution) in process baths to decrease the amount of drag-out.
- Withdraw workpieces from tanks slowly to allow maximum drainage back into process tank.
- Use air knives or spray rinses above process tanks to rinse excess solution off of workpiece and into process bath.
- Install drainage boards between process tanks and rinse tanks to route drag-out back into process tank.
- Use dedicated drag-out tanks after process baths to capture drag-out.
- Install rails above process tanks to hang workpiece racks for drainage prior to rinsing.
Rinse Systems
- Use spray rinses as initial rinse after process tank and before dip tank.
- Use air agitation or workpiece agitation to improve rinse efficiency.
- Install multiple rinse tanks (including counter flow rinse tanks) after process baths to improve rinse efficiency and reduce water consumption.
Recycling and Resource Recovery
- Reuse the acid rinse effluent as influent for the alkaline rinse tank, thus allowing the fresh water feed to the alkaline rinse tank to be turned off (Reactive rinsing). This can also be applied to process tank rinses.
- Treat rinse water effluent to recover process bath chemicals. This allows the reuse of the effluent for rinsing or neutralization prior to discharge.
- Reuse the spent reagents from the process baths in the waste water treatment process.
- Recycle spent solvents on-site or off-site.
- Use treatment technologies to recycle rinse waters in a closed loop or open loop system.
- Some recycling and most treatment processes require a permit. Make sure to contact the Hazardous Waste Advisement Program to determine if you need a permit to treat or recycle your wastes.
Treatment Alternatives
- Pretreat process water to reduce the natural contaminants which contribute to the sludge volume.
- Use treatment chemicals that reduce sludge generation (e.g., caustic soda instead of lime).
- Use sludge dewatering equipment to reduce sludge volume.
Additional Publications
Some additional publications that may be helpful in overall management of hazardous waste are available from Hazardous Waste Advisement Program.
Hazardous Waste Information Series:
- Classification of Hazardous Waste Generators
- Hazardous Waste Minimization
- New Jersey's Hazardous Waste Regulatory Program
- Standards for Hazardous Waste Treatment, Storage and Disposal Facilities
- Toxics in the Home
- Transporters
- Uniform Hazardous Waste Manifest
Newsletters:
- Hazardous Waste Quarterly
- Small Quantity Generator Newsletter (9/88)
Technical Information Publications (TIP):
- Metal Manufacturing
- Vehicle Maintenance
Waste Minimization Publications:
- 8/85 Waste Minimization Seminar Proceeding
- 11/87 Waste Minimization Workshop Proceedings
- 5/89 Waste Minimization Conference Proceedings
- Assessment of Reduction and Recycling Opportunities for Hazardous Waste Manual
- Pollution Prevention Grant Program Summary
Other Publications:
- A Citizen's Guide to the Major Hazardous Waste Facilities Siting Act
- List of Commercial Hazardous Waste Facilities in New Jersey
- New Jersey's Hazardous Waste Management Program
- Hazardous Waste Q&A
Regulations:
- Hazardous Waste Regulations (N.J.A.C. 7:26-1 et al.)
- Unified Hazardous Substance List
Water Resources Publications:
- Field Guide
- Resource Manual
- Clean Water Book
- Non-Point Source Pollution
- Solution to Pollution
Further Information
For information about regulatory requirements contact the Hazardous Waste Advisement Program at (609) 292-8341 or write to:
New Jersey Department of Environmental Protection
Division of Hazardous Waste Management
401 East Street, CN028, 5th Floor
Trenton, New Jersey 08625
Attn: Hazardous Waste Advisement Program
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Last Updated: October 10, 1995