Vol. 6, No. 1 - February 1997

Index this issue . . .

Eliminate/Reduce Oil Changes With By-Pass Filters!

By-pass filtration is becoming a proven technology that significantly extends oil and engine life and reduces engine problems and vehicle maintenance costs.


Oil itself does not "break down," i.e., it does not lose its lubricating capability. Oil changes are necessary because water gets into the oil, additives deteriorate, and contaminants build up. All three contribute to increased engine wear. Vehicle engines are usually equipped with full-flow filters to remove particles from the oil that are typically 40 microns (Ám) and larger in size, e.g., grit. The most damaging contaminants, however, are particles less than 10 Ám in diameter. In addition, full-flow filters do not remove other contaminants such as water, fuel, and gases.

The by-pass filter does not replace the full flow filter: it is installed in addition to and in parallel with it. With the by-pass filter, approximately 10 percent of the total oil flow is diverted through the by-pass filter in a continuous cycle. In this superior filtration system, the by-pass filter cleans the oil by removing particles even less than 1 Ám as well as the detrimental water, fuel, and gases. Since the contaminants are removed, the oil will no longer need to be changed. However, oil may need to be added to replace the amount lost during engine combustion and filter replacement. Contaminant removal with the by-pass filter has proven to extend engine life. In addition, by-pass filters are easily transferable between vehicles at vehicle replacement.

Although the oil itself will no longer need to be changed, the filters (both full-flow and by-pass) will need to be changed periodically. A current test on one diesel fleet that was near the 100,000-mile point without an oil change shows that the full-flow filters need to be changed about every 40,000 miles and the by-pass filters about every 15,000 miles. As supported by periodic oil analyses, these intervals may continue to be increased and, thus, oil filter replacement and disposal costs continue to be reduced.

Study Results

The Society of Automotive Engineers reported a successful 12-year study on the use of by-pass filters in school buses that resulted in an 80-percent reduction in oil usage. In addition, several Florida school buses equipped with the by-pass filter have gone 5 years without an oil change. By-pass filters have been used in critical-service marine engines for several years, including those of the major oil companies.

A 1991 test of by-pass filters on heavy-duty, on-highway trucks resulted in an increase in oil drain intervals from 16,000 miles to an average of 94,000 miles (as supported by periodic oil analyses), an 83-percent reduction in oil consumption, and a payback of one year. Contact DPPEA at 919-715-6500 for information on by-pass filter studies.


Capital costs for by-pass filters are approximately $75 to $140 per unit for cars and vans and $175 to $400 per unit for trucks. This technology can be easily implemented and should prove successful with periodic oil quality analysis. Hand-held oil analyzers are available to determine when the oil requires further laboratory testing.

By-pass filters can be used not only on vehicle oil systems but also on vehicle hydraulic systems and transmissions and on garage parts washers.

The Department of Defense, some truck fleets, the North Carolina Department of Transportation, and the State Highway Patrol are currently using by-pass filters in various applications. Motor Fleet Management and North Carolina school buses are planning to use them in the near future.

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Reusable Filters

Reusable oil filters eliminate oil filter inventory and disposal costs. Reusable full-flow filters are similar in size and shape to the disposable full-flow filters commonly used. However, the reusable filter contains a metal media instead of the typical paper media. This metal media can be removed and cleaned quickly and easily and then re-installed in the same filter housing. The cleaning process, which involves circulating or soaking the filter in a cleaning fluid and then blowing it with compressed air, typically requires only as much time as a disposable filter change.

Reusable filters cost $60 to $300 depending on the size of the filter.

With the reusable full-flow filter, oil still needs to be changed routinely, although the intervals between changes may be extended with oil analysis. Reusable by-pass filters are also available.

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A Waterless Carwash?

Contact DPPEA at 919-715-6500 for information on available products.

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Automotive Wastes Subject to Statewide Disposal Bans

Restricted Material

Restricted From

Effective Date of Ban


L and I

July 1, 1994

Lead-Acid Batteries

L and I

January 1, 1990



March 1, 1990

Used Oil


October 1, 1990

L = Landfill; I - Municipal Solid Waste Incinerators

Contact DPPEA at 919-715-6500 for Fact Sheets that discuss proper management of these materials.

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Filter and Engine Warranty Concerns

Filter manufacturers and vehicle manufacturers have discussed warranties extensively. If an engine problem cannot be directly attributed to the use of a by-pass or reusable oil filter, the vehicle warranty remains in effect. Most filter manufacturers guarantee their products; thus, if a vehicle manufacturer claims the engine problem was caused by the oil filter, the filter manufacturer will repair/replace the engine and then address the situation with the vehicle manufacturer. Oil analysis is usually required to support the use of by-pass or reusable oil filters if a problem occurs.

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Wastewater From Vehicle Washing

With a permit issued by the proper authority, facilities that wash vehicle bodies may recycle washwater or discharge it to a sanitary sewer or a septic system. Facilities that wash vehicle engines must either discharge to the sanitary sewer or install an on-site recycling system. North Carolina statutes prohibit discharge of any vehicle washing wastewater to a storm sewer, either by runoff or direct outlet.

Washwater Recycling Systems

Recycling systems provide several advantages over washwater disposal:

  1. These systems allow for simple clean up of contaminants from spills or system failures by preventing entry to the sanitary sewer or septic system.
  2. These systems reduce costs for water use and disposal.
  3. Many of the systems are pre-engineered, have a proven track record, and can be submitted for permit issuance from previously approved plans and specifications.

The regional staff for the NC Division of Water Quality can provide additional details on permits for a recycling system.

A typical washwater recycling system consists of a sedimentation basin for grit/sand removal, an oil/water separator, and a disinfection unit to prevent biological growth. Pre-engineered units for single wash bays cost approximately $20,000. Periodically, the washwater must be changed because of the build up of dissolved solids (salts) in the water. The water can be disposed in the sanitary sewer if little or no oil is present or, if oil is present, by a waste oil company. Contact DPPEA at 919-715-6500 for manufacturers of these systems.

Washwater Disposal

Discharge to a sanitary sewer requires a permit from the local wastewater treatment authority. This alternative may require less expensive permit and capital costs, but the facility must pay sewer discharge fees and will be required to meet limits on oil and grease.

Another alternative, septic system discharge, requires a permit from the North Carolina Division of Environmental Health. A permit may cost several thousand dollars in engineering fees and may take many months for approval. These systems have shown a tendency to fail, which can lead to soil and groundwater contamination and, in turn, result in drastic reductions in property values such that potential buyers may not be able to obtain loans. In addition, the facility's clean-up costs could be extensive.

Although vehicle washwater discharge to a septic or sanitary sewer system may be permitted, recycling systems are an economical management alternative, especially for vehicle washing facilities in rural areas without a municipal sewer.

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Did you know . . .

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Requirements for Alternatively Fueled Vehicles

The Energy Policy Act of 1992 (EPAct) included a provision that public and private fleets begin purchasing an increasing percentage of light-duty trucks and passenger cars that are alternatively fueled vehicles (AFVs). The primary objectives of this provision are to stem the nation's increasing reliance on imported petroleum and to reduce the impact of the transportation sector on urban air quality. Potential alternative fuels include compressed natural gas, liquefied petroleum gas, and electricity.

The requirement applies to private fleets of 50 or more vehicles and public fleets of 20 or more vehicles that primarily operate in urban areas. Affected areas in North Carolina include the metropolitan statistical areas (MSAs) of Charlotte, the Piedmont Triad, the Research Triangle, and Hickory/Morganton. Currituck County is also affected because of its proximity to Norfolk-Newport News-Virginia Beach. The table shows the percentage of new vehicle purchases that must be AFVs.

New Alternatively Fueled Fleet Vehicle Purchase Requirements, %

Model Year

Federal Fleets

State Fleets

Fuel Provider



















































Earn Credits

Fleet operators purchasing either a greater percentage of AFV vehicles than required or purchasing them ahead of the required timeline can earn credits to bank, market, or transfer to other affected fleets. Federal tax deductions and credits are also available to defray start-up costs of purchasing AFVs and establishing refueling stations for AFVs.

Refueling Infrastructure

According to the North Carolina Energy Division, an alternative fuels refueling infrastructure is developing in affected MSAs. Plans are to connect major MSAs and to offer grants for AFV purchases.

A grant program administered by the NC Division of Air Quality that focuses on the reduction of mobile source emissions has funded several alternative fuels projects in recent years. Contact Heather Hildebrandt at 919-733-1498 for more information.

For more information about AFVs and requirements under EPAct, contact Al Ebron of the North Carolina Energy Division by telephone at 919-733-1892 or by e-mail. The U.S. Department of Energy's Alternative Fuels Hotline is 1-800-423-1363, and the DOE's Alternative Fuels Data Center maintains an informative Web site.

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Case Studies

Filters Extend Parts Washer Solvents

Currently, the North Carolina Division of Highways Equipment Depot has installed filters on 7 of its 10 parts washers in order to extend the working life of traditional mineral-based solvents. Parts washers are used during routine maintenance of off-road vehicles. The filters, which cost approximately $70 each, utilize a disposable paper towel filter media which removes fine contaminant particles down to approximately 2 microns in size.

Solvent life has been extended to approximately one year; and, to replace evaporative losses, the facility is adding only 2 gallons of solvent for every gallon of parts washer capacity each year. Under a previous service contract, the facility replaced 6.5 gallons of solvent for every gallon of parts washer capacity each year. The total costs have declined significantly: from $18 per gallon of capacity per year for virgin solvent and waste management costs under the previous contract to $10.96 per gallon of capacity per year in solvent costs to replace only evaporative losses.

With its use of the filters, the facility has eliminated the service contract as well as two parts washers. A small amount of sludge, potentially less than 1 drum, is expected to be generated each year. In addition, the Depot has been reclassified from a large quantity generator to a small quantity generator of hazardous wastes under RCRA. For more information, contact Tom Martin, Depot Superintendent, at 919-733-3535.

Aqueous Parts Washer Replaces Solvent

The North Carolina National Guard (NCNG) - Combined Support Maintenance Shop in Raleigh services military vehicles up to 20 tons in weight from 100 armories throughout North Carolina. In 1993, the facility purchased a 2,000-pound aqueous jet washer that cleans a range of vehicle components up to an entire engine block. Over a typical 40-minute cycle time, the unit recirculates 140 gallons of biodegradable soap solution. Small quantities of defoamer and rust inhibitor must be periodically added to the solution. When not in use, the soap solution is held in a reservoir that is equipped with an oil skimmer to remove oil and grease. After an initial testing period for metals, the NCNG now discharges the spent soap solution to the sanitary sewer system every 2 to 3 weeks.

The capital cost of the jet washer was $10,000, and solution replacement costs amount to $40 every four weeks, or $480 annually. However, the jet washer has eliminated the need for two solvent parts washers and one carburetor cleaner unit, which cost $3,030 annually to operate. Additional benefits include reduced labor for parts cleaning, reduced labor and liability for hazardous waste management, and improved safety for employees. As a result of the advantages and effectiveness of the jet washer, the NCNG recently purchased a second unit. For more information, contact Joseph Howard, Environmental Protection Specialist, at 919-664-6283.

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DPPEA Awards FY 96-97 Challenge Grants

Under its annual Challenge Grants Program, the Division of Pollution Prevention and Environmental Assistance (DPPEA) has awarded $38,300 in grants for FY 96-97. Challenge Grants are awarded to industries for innovative pollution prevention projects or technologies that can be easily transferred to other industries or industry types. The current grants were issued to the following companies:

Grant Recipient

Waste Reduction Activity


Carolina Power & Light Company Inc.

Demonstrate a system to separate flyash into carbon-rich and carbon-depleted streams. The carbon-rich stream will be returned to the power plant boiler and re-burned to utilize the residual energy source, and commercial recycling opportunities for the carbon-depleted stream will be examined.


Converse, Inc.

Demonstrate water-based adhesives and infrared curing in place of solvent-based adhesives in athletic shoe manufacturing.


Eaton Corp.

Demonstrate the process for developing an Environmental Management System following the guidelines for ISO 14001.


Miller Control and Manufacturing Company Inc.

Demonstrate alternative fiberglass lay-up procedures incorporating the use of scrap fiberglass as filler to reduce styrene resin requirements and associated emissions by 20%.


Total Awards


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Multimedia News Update

Air Quality News

The United States Environmental Protection Agency (EPA) has proposed more stringent ambient air quality standards for particulate matter and ozone (61 FR pp. 65637-65713 and 65715-65750, December 13, 1996). The Agency proposes to retain the existing particulate matter standard for 10 micrometer particles, add a more restrictive standard for smaller 2.5 micrometer particles, and change the ozone standard from the current 0.12 to 0.08 parts per million. EPA is accepting comments on these proposed standard changes until February 18, 1997.

These standards are part of EPA's National Ambient Air Quality Standards (NAAQS), which are health-based and intended to protect public health with an adequate margin of safety. The current levels of ambient ozone and particulates throughout the U.S. have been linked to increased respiratory ailments, asthma, and allergies. Children, the elderly, and those with chronic heart and lung diseases are most affected by the air pollutants.

With passage of these new rules, some North Carolina industries may be required to implement additional air pollution controls after obtaining the appropriate permits. However, before installing any pollutant control device, the affected facility should consider conducting a pollution prevention assessment to identify the locations, sources, and causes of the air pollutants. The facility can then develop techniques to reduce the air emissions at the point of generation to avoid additional costly controls and related permitting and reporting requirements. For specific information on pollution prevention for air emission sources, contact DPPEA at 919-715-6500.

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Solid Waste News

The North Carolina Recycling Business Assistance Center (RBAC), created in 1995, is a cooperative effort between and the Department of Commerce. The RBAC mission is to promote environmentally sound economic development through the reuse and remanufacture of recyclable materials. It seeks to bolster the State's economy by working to maximize recycling's potential to create jobs, increase manufacturing, and reduce solid waste.

RBAC staff responds to technical assistance requests concerning the quantity and location of recyclable materials and by identifying capacity potential for business expansion, conversion to recycled feedstock, and business start-ups. The RBAC also promotes the development of new recycling technologies such as increasing the percentage of asphalt shingles in pavement and testing the potential for recycled drywall as a soil amendment, oil absorbent, and animal waste treatment.

For more information about the RBAC, call Bobbi Tousey, RBAC Manager, at 919-715-6522 or 800-763-0136.

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Water Quality News

Sara Lee Knit Products in Morganton, N.C., recently installed a 7-gpm ultrafiltration/nanofiltration membrane system to recover valuable chemicals and facilitate the economical reduction of color in the effluent. The system will be used on selected drops of dark-colored reactive dyebaths.

Figure 1 illustrates the ultrafiltration/nanofiltration process.

The installation of a dual effluent piping system for all the dyebaths in the facility enables Sara Lee Knit Products to select only those discharges with the most color and chlorides. This selective capability not only dramatically reduces the volume of wastewater requiring treatment, it also recovers the greatest portion of reusable chemicals (see Figure 1).

A portion of this project was funded by the U.S. Department of Energy's National Industrial Competitiveness in Energy, Environment, and Economics (NICE3) program, which provides partial funding for the commercialization of innovative technologies. For more information on the NICE3 program, contact John Burke of DPPEA at 910-249-1480.

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Hazardous Waste News

EPA is drafting revisions to the hazardous waste recycling regulations. These revisions address secondary materials under two different approaches: (1) "in-commerce" and (2) "transfer-based."

It is expected that these potential draft changes will be announced in the Federal Register in 1997. See the Hazardous Waste Section's home page for additional information.

The North Carolina Risk Analysis Framework: Methods for Determining Contaminant Target Concentrations in Soil and Groundwater is a guidance document developed by staff for public comment that proposes procedures for setting risk-based clean-up levels or contaminant target concentrations in soil and groundwater at chemically contaminated sites. Dates and locations of the public meetings are listed in the chart.

Public Meetings

Date (1997) 7:00 p.m.


February 6


Teaching Auditorium, Rowan-Cabarrus Community College

February 11


Auditorium, Dept. of Transportation Highway Bldg.

February 13


Fulford Bldg., Room 153, Pitt County Community College

February 18


Ground Floor Hearing Room, Archdale Building

More information can be obtained on the Internet or by calling (919) 733-8486 to request a copy of the draft Framework.

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Date (1997)


Carolinas Woodworking & Furniture Supply Show

Greensboro, NC

February 14-15

Edison Trade Shows, Inc., 704-459-9894

Water Conservation Issues

Madison, WI

February 17-20

Univ. of Wisconsin-Madison, College of Engineering, 800-462-0876

Industrial Wastes Technical Conference

New Orleans, LA

March 2-5

Water Environment Federation, 800-666-0206

NC Recycling Association Annual Conference

Asheville, NC

March 17-19

NCRA, 919-851-8444

National Pollution Prevention Roundtable

Denver, CO

April 2-4

NPPR, 202-466-7272

Total Life Cycle Conference: Land, Sea, and Air Mobility

Auburn Hills, MI

April 7-9

Dee Tripp, SAE, 412-772-8539

Advancing Filtration Solutions: Tenth Annual Technical Conference and Exhibition

Minneapolis, MN

April 29 - May 2

American Filtration & Separations Society, 205-333-6111

Small and Large Quantity Hazardous Waste Generator Courses


Small: May - TBA;
Large: Aug./Sept. - TBA

Linda Culpepper, Hazardous Waste Section, , 919-733-2178, ext. 216

Air & Waste Mgmt. Assn. Annual Conference

Toronto, Canada

June 8-13

Air & Waste Mgmt. Assn., 412-232-3444

Engineeering Solutions to Indoor Air Quality Problems

Raleigh, NC

July 21-23

Air & Waste Mgmt. Assn., 412-232-3444

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FOCUS: Waste Minimization is published by the Division of Pollution Prevention and Environmental Assistance, the Division of Waste Management, Division of Air Quality, and Division of Water Quality of the North Carolina Department of Environment and Natural Resources. It is intended to provide North Carolina industries and other interested parties with current information concerning proper waste management and waste reduction. The information contained in this publication is believed to be accurate and reliable. However, the application of this information is at the reader's own risk.

Mention of products and services in the publication does not constitute an endorsement by the State of North Carolina. The information contained in this publication may be cited freely.

If you have any comments, waste minimization case summaries, resource information, or questions for the next issue of the FOCUS newsletter, telephone Susan Clarke at (919) 715-6503, fax (919) 715-6794, e-mail, or write the N.C. Division of Pollution Prevention and Environmental Assistance, 1639 MAIL SERVICE CENTER, RALEIGH NC 27699-1639.

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The North Carolina Division of Pollution Prevention and Environmental Assistance provides free, non-regulatory technical assistance and training to eliminate, reduce, or recycle wastes before they become pollutants or require disposal. For additional information about any of your waste reduction concerns, contact DPPEA at (919) 715-6500 or 800-763-0136 or e-mail.

DPPEA-97-01. February 1997