Fact Sheet: Hazardous Waste Generated by Metal Refinishing Facilities

California Department of Health Services
Toxic Substances Control Program
Alternative Technology Division

April 1990

Waste Background

There are over 31,000 metal finishing facilities in the United States. They vary Reduction in size, age and types of operations. They all have one thing in common: the for Metal generation of hazardous waste from the production processes. Reducing the generation of hazardous waste can save you money and at the same time definishers crease your future liabilities!

Typical wastes generated are:

• Industrial wastewater and treatment residues
  
• Spent plating baths
  
• Spent process baths
  
• Spent cleaners
  
• Waste solvents and oil

Both state (Health and Safety Code, Article 11.8, Section 25244.4) and federal (40 CFR, Part 262, Subpart D) regulations require that generators of hazardous waste file a biennial generator's report. Among other things, 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.

California state law also permits the Department of Health Services (DHS) to request that generators of recyclable wastes provide a written statement to justify not recycling the waste (California Code of Regulations, Title 22, Article 12, Section 66763).

Missing Text; see source document

'Me Uniform Hazardous Waste Manifest requires that large generators 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

This Fact Sheet was produced by the Technology Clearinghouse Unit to assist generators throughout the State of California. selected the "practicable method of treatment, storage, or disposal currently available ... which minimizes the present and future threat to human health and the environment". Small quantity generators must certify that they have made a "good faith effort to minimize ... waste generation" and have selected the best affordable waste management method available.

Since waste reduction methods reduce the amount of waste generated, and also the amount subject to regulation, these practices can help a shop comply with the requirements and save money. The following is a list of some common waste reduction methods for metal finishing shops.

Begin at the Top

• The shop's owner or manager must be committed to waste reduction and pass that commitment on to the employees.
  
• Establish training for employees in waste reduction, hazardous material handling and emergency response.
  
• Establish incentive programs to encourage employees to design and use new waste reduction ideas.

Assess Hazardous Waste

Waste assessments are used to list the sources, types and amounts of hazardous waste generated to make it easier to pinpoint where wastes can be reduced.

Source reduction is usually the least expensive approach to minimizing waste. Many of these techniques involve housekeeping changes or minor inplant process modifications.

Improved 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.
  
• Designate protected raw material and hazardous waste storage areas with spill containment. Keep the areas clean and organized and give one person the responsibility for maintaining the arras.
  
• Label containers as required and cover them to prevent contact with rainfall and avoid spills.
  
• 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.
  
• 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 process chemistries which are treatable or recyclable on-site.
  
• Use deionized water instead of Lap water in process baths and/or rinsing operations to reduce sludge generated.
  
• Use non-chelated process chemistries rather than chelated chemistries to reduce sludge volume.
  
• Replace cyanide process baths with non-cyanide process baths 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 Both Life

• Treatment (Filtration, Electrolytic Dummying, etc.) of process baths 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.
  
• 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 counterflow rinse tanks) after process baths to improve rinse efficiency and reduce water consumption.

Reactive Rinses

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 wastewater 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. Be sure to contact your local DHS regional office to determine if you need a permit to treat or recycle your wastes.
  
• 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.
  
• Use treatment technologies (such as ion exchange, evaporation, and electrolytic metal recovery) that do not use standard precipitation/clarification methods which generate heavy metal sludges.

Further Information

For more information, contact the Technology Clearinghouse in the Alternative Technology Division at:

Department of Health Services
Toxics Substances Control Program
Alternative Technology Division
714/744 P Street
P.O. Box 942732
Sacramento, CA 94234-7320
(916) 324-1807

56697

State of California-Health and Welfare
Department of Health Services
Toxic Substances Control Program
714/744 P Street
P.O. Box 942732
Sacramento, CA 94234-7320

For information about your regulatory requirements, contact the DHS regional office nearest you:

Region I Sacramento (916) 855-7700
Fresno (209) 445-5938
Region 2 Berkeley (415) 540-2122
Region 3 Burbank (818) 567-3000
Region 4 Long Beach (213) 590-4868

To get an EPA ID number, call:

DHS, Toxics Program,
Program and Administrative Support Division (916) 324-1781

Metal Finishing shop owners and operators may be able to get additional information from:

• Registered hazardous waste haulers
  
• Trade associations
  
• Recycling or treatment equipment vendors or services
  
• Informational workshops