ECAR Fact Sheet for Arizona
Aqueous Cleaning

Regulations
Self-Audit Checklist
Best Management Practices
Contacts
Related ECAR Fact Sheets
Other Relevant Resources

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The following fact sheet was prepared by the ECAR Center staff. Once prepared, each ECAR Center fact sheet undergoes a review process with the applicable state environmental agency(ies). You can check on the status of the review process here. Please read the disclaimer on the status page. While we have tried to present a summary of the essential information on this topic, you should be aware that other items, such as local regulations, may apply to you.

What You Need to Know

Various methods are used to clean oil and grease from auto parts before sale. This fact sheet covers the environmental issues associated with aqueous cleaning methods such as enclosed spray washers, hot dip tanks, pressure washers, and steam cleaning. Solvent Cleaning (e.g., Stoddard solution, mineral spirits) is covered under a separate fact sheet.

Aqueous cleaners are one of the most popular choices for degreasing parts at automotive recyclers and are a good alternative to petroleum-based and halogenated solvents. Some of the benefits of aqueous cleaners are that:

• There is less risk of hazardous exposure for workers;
• They are not flammable or explosive;
• The oils and greases can be removed more effectively; and
• They can provide potential savings in disposal costs, since used aqueous cleaning water may be eligible for discharge into public sewer systems.

Regulations

With aqueous cleaning processes there are two major environmental concerns:

• Oil, sludge, sediment and similar concentrated wastes that are removed from cleaning operations (e.g., cleanout of sumps).
• Wastewater, which may be contaminated with oil and/or metals such as lead and zinc.

Management and disposal options for these two wastes are discussed below, as well as used filters.

Oil, Sludge, Sediment. Oil skimmed from an aqueous cleaning solution can be managed as used oil and recycled. Most recyclers will accept skimmed oil with used motor oil as long as it is not contaminated with solvent. Contaminated oil and other solids that are removed from aqueous cleaning operations should be managed as hazardous waste unless you have performed tests that indicate they are non-hazardous. For more information, see the ECAR Hazardous Waste fact sheet. If the wastes are non-hazardous, then you should maintain test records that support your determination.

Wastewater. Nonhazardous spent aqueous cleaning solutions can be discharged to your local sewer system or treatment plant if they meet local discharge limits and with the appropriate permits. The sewer authority/treatment plant may require you to treat your cleaning solution before discharging to the sewer. Contact your local sewer authority to find out their requirements. The discharge of cleaning solutions to the sanitary sewer also may require a permit from the Arizona Department of Environmental Quality (ADEQ).

Spent parts washer cleaners, both solvents and aqueous cleaners, should never be discharged to a septic system or storm water sewer.

Used Filters. Some metal casing filters may be recycled along with spent engine oil filters with the permission of the recycler. Contact your oil recycler to determine if they will take your filters. Plastic and cloth filters should not be recycled with used oil filters. These filters should be managed as hazardous waste and disposed of by a licensed waste disposal company.

Pretreatment. To meet these rules, you may need to install treatment equipment such as an oil/water separator to prevent oil and sludge from being discharged to the sewer. This is referred to as "pretreatment." The oil and sludge collected by pretreatment equipment will have to be periodically removed and disposed of. The skimmed oil may be eligible for recycling along with your used oil. However, other parts of the mixture may need to be managed as a hazardous waste (you must make a hazardous waste determination). In most instances, wastewater will require some form of pretreatment prior to discharge into the sewer system.

Links to the Regulations and Forms. Use the following links to view the regulations and permit forms pertaining to aqueous cleaning.

Arizona Water Quality Requirements

Federal Safe Drinking Water Act Requirements

Self-Audit Checklist

When an inspector comes to your facility, there are certain things he or she checks to see if you are in compliance with environmental regulations. It makes good sense for you to perform a "self-audit" and catch and correct problems before they result in penalties. Also, there are some compliance incentives associated with self-audits (see Audit Policy Page).

Use the following list to audit your aqueous cleaning operation.

1. Are the sludges generated by cleanout of sumps and similar devices associated with aqueous cleaning properly managed and disposed of? Perform a hazardous waste determination for these wastes. If they are found to be hazardous, you must manage them on-site according to hazardous waste rules and dispose of them at an approved facility.
2. Does your facility discharge wastewater from aqueous cleaning? Are the discharges authorized by a permit? Check all uses of water and steam. Determine where wastewater is generated and discharged. You must have a permit or written authorization for all industrial wastewater discharges. Be certain that floor drains and sinks do not discharge to the ground, a septic tank, a storm sewer or a waterway.
3. Determine whether the aqueous cleaning solution discharge will be accepted by the local sewage treatment plant. Obtain all required permits or approvals prior to discharge.
4. If discharge to a sewage plant is not allowed, arrange to recycle and reuse the solution, or properly dispose of the solution. You may need to test the solution to determine whether it is a hazardous waste.

Best Management Practices (BMPs)

Most regulations tell you what you have to do to be in compliance, but they don't explain how to do it. That's where "best management practices" come into play. BMPs are proven methods that help you to get into compliance and stay there. The following BMPs are recommended for aqueous cleaning.

• Install cleaning equipment that efficiently uses water or is capable of recycling water.
• Install an on-site capture and reuse system for wastewater. These are commonly used by auto recycling facilities in association with pressure washers and enclosed spray washers.
• Remove caked-on grease and oil from parts with a scraper or knife before aqueous cleaning to reduce cleaning time and water usage.
• Very heavily soiled parts should be pre-cleaned by wiping with a rag.
• Conduct cleaning operations on a contained or indoor impervious surface.
• Do not dispose of used cleaning solution on the ground or into a storm drain.

Contacts

1. For more information, contact the Arizona Department of Environmental Quality (ADEQ) Water Quality Division at 602-771-4385.
2. To report a spill or leak, call the Arizona ADEQ Emergency Response number at 602-771-2330 or toll free at 800-234-5677. To report a leaking underground storage tank, call 602-771-4303.
3. To report an environmental incident or complaint, contact the nearest regional office.

Related ECAR Fact Sheets

1. Solvent Cleaning
2. Wastewater
3. Hazardous Waste

Other Relevant Resources

1. Arizona Green Business Automotive Program
2. Fact Sheet on Managing and Reducing Parts Washer Wastes (Illinois Document)

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