The type of O/WS most frequently used by the Air Force is the gravity separation system. The performance of gravity separation systems is a function of the relatively low water solubility of petroleum products in water and their different specific gravities. (NOTE: The specific gravity of a petroleum product is defined as its density divided by the density of water. Since the density of petroleum products is less than that of water, they will float.) Solids, if present in the waste stream, will generally collect at the bottom of the O/WS holding tank and can be periodically removed when the tank is drained for maintenance.

A drain connected to an oil/water separator may be perceived as a convenient place to dispose of any type of liquid waste or sludge. This erroneous assumption can result in illegal discharges of hazardous substances to installation sewer systems (which eventually discharge to surface waters) or wastewater treatment plants. The illustration in Figure 1 shows, in simplified form, the operation of a typical gravity O/WS system.

Occasionally, simple gravity type O/WSs do not remove enough oil for the resulting wastewater to meet regulatory discharge requirements. In these cases, coalescing oil/water separators, which are essentially enhanced gravity-type O/WSs, are needed to achieve greater separation efficiency.

According to Stoke's Law, a 100-micron diameter oil droplet will rise approximately 6 inches in water every ten minutes. A 20-micron diameter oil droplet will take over two hours to rise the same distance. Because an oil droplet must rise approximately 48 inches to reach the water surface in a typical gravity- type oil/water separator, smaller droplets may pass through uncollected. Coalescing (binding together) the smaller oil droplets makes them larger and more buoyant, causing them to rise faster. Coalescing oil/water separators may use inclined plates placed within the separation chamber, which provide only a short vertical distance (1/4") for the small droplets to travel before they encounter a fixed surface. Here they can coalesce with other droplets and continue to rise along the plates to the water's surface. Another coalescing method uses a filter made of fine oleophillic (oil "loving") fibers such as polypropylene. The fine oil droplets attach to the fibers as the wastewater flows through. As the droplets get larger, they become buoyant enough to detach from the fibers and rise to the surface, where they can be collected.

Figure 1. Conceptual Diagram of a Simple Gravity Oil/Water Separator. In a gravity operated O/WS, the oily wastewater is introduced through the system inlet. Water turbulence is calmed in the inlet chamber behind the first baffle, where solids settle out and form a sludge on the bottom of the chamber. As the wastewater flows over the first baffle to the middle, or separation, chamber, oil droplets rise to the surface and are trapped behind a second, higher baffle, which has an opening along its bottom edge. The remaining water passes under the second baffle into the outlet chamber, where it is diverted to a discharge point. Consequently, solid sludges can be collected from the bottom of the inlet chamber and oil droplets that accumulate at the water's surface in the separation chamber can be skimmed off or otherwise routed to a separate holding tank.

Governing Laws and Regulations
Clean Water Act (CWA) (33 U.S.C. . 1251, et seq.). Compliance with the CWA requires municipalities to mandate the concentrations of certain contaminants allowed in discharges directed to the local wastewater treatment plant. Under the CWA, the National Pollutant Discharge Elimination System (NPDES) Permit Program (Title 40 Code of Federal Regulations (CFR) Part 122) regulates the quality of point-source wastewater discharges to the environment via sewer systems on DoD installations or from publicly owned treatment works (POTW). Therefore, discharges to a local storm water conduit must be covered by a NPDES permit. To discharge to a local sanitary sewer system, the generator must demonstrate compliance with water quality standards as mandated by the POTW operator, who is ultimately responsible for the quality of their own NPDES-permitted discharge.

Some pollutant discharges to a sanitary sewer may interfere with the operation of the POTW. Sections 204, 208, 301, 304, 307, and 309 of the CWA prohibit the discharge of some pollutants to POTWs and require pretreatment for other discharges. Thus, the CWA requires POTWs to develop local limits for discharges of nondomestic wastewater to the POTW. These regulations are codified at Title 40 CFR Part 403, General Pretreatment Regulations. Discharges to a sanitary sewer system from oil/water separators may require monitoring for oils and greases, total organic compounds, and total suspended solids in order to ensure compliance with POTW established limits.

Section 311 (Oil and Hazardous Substance Liability) of the CWA establishes requirements for preventing discharges of oil and other hazardous substances, and requires certain action for spills. These regulations are codified at Title 40 CFR Parts 110, 112, 116, and 117.

Oil Pollution Act (OPA) (Title 33 U.S.C. . 2701, et seq.). The OPA establishes liability for corrective action and damages for those parties responsible for a facility from which oil is discharged, or that poses the substantial threat of an oil discharge to surface waters. Regulations promulgated under the Oil Pollution Act pertinent to oil/water separators include Title 40 CFR Part 110, Discharge of Oil, and Title 40 CFR Part 112, Oil Pollution Prevention, which establishes requirements for the preparation and implementation of Spill Prevention Control and Countermeasure (SPCC) plans.

Federal Facility Compliance Act (42 U.S.C. . 962, et seq.). Waste stream discharges by installations to their own federally operated treatment works (FOTWs) historically have not been subject to federal pretreatment regulations. However, proposed administrative rules implementing the Federal Facilities Compliance Act will subject FOTWs to the same pretreatment requirements applicable to POTWs found in Title 40 CFR Part 403 if any single on-base activity generates more than 220 pounds of hazardous wastewater per month, or generates any amount of acutely hazardous waste.

Resource Conservation and Recovery Act of 1976 (RCRA) (42 U.S.C. . 6901, et seq.). With a few exceptions, underground storage tank (UST) regulations (Title 40 CFR Part 280) promulgated under RCRA do not apply to oil/water separators (i.e., "process waste traps"). RCRA does not specifically exclude O/WS tanks from regulation; however, the UST regulations do provide exclusions and deferrals applicable to almost all O/WSs. Because all POTWs (and certain private treatment facilities) are regulated under the CWA, they are excluded from RCRA UST regulations. When O/WSs discharge (with permission) to a POTW regulated under the CWA, the O/WS is excluded from RCRA UST regulations.

Oil/water separators that do not have permission to discharge to a POTW, and do not have (or do not qualify for) a NPDES discharge permit (i.e., their "pre-treated" wastewater is periodically removed and hauled to a treatment facility), are deferred from having to meet Title 40 CFR Part 280 (Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks), Subparts B, C, D, E, and G. However, such tanks would be subject to the corrective action and financial responsibility requirements of Subpart H should a release occur. More information concerning RCRA-regulation of O/WS tanks is presented in a 1989 letter to Hunt & Hunt Engineering from the United States Environmental Protection Agency (EPA), copies of which are available from PRO-ACT.

If O/WSs are improperly used, their sludges and oils can become contaminated with a variety of hazardous substances. Should these hazardous substances leak into the environment, the O/WS may be designated a "solid waste management unit," or SWMU, and be subject to corrective actions under RCRA regulations in Title 40 CFR Subpart F, Releases from Solid Waste Management Units.

(NOTE: Title 40 CFR Part 63, Subpart VV, National Emission Standards for Oil-Water Separators and Organic-Water Separators, regulations do not apply to O/WSs at Air Force installations. They are intended to apply to large treatment facilities that have the potential to emit many tons of air pollutants per year.)

Pollution Prevention Act (Title 42 United States Code (U.S.C.) . 13101, et seq.). The Pollution Prevention Act (PPA) makes pollution prevention (P2) the national policy of the United States. The primary goal of the PPA is to reduce the amount of pollutants entering a waste stream or the environment. This Act also established the "P2 hierarchy," which requires that pollution first be prevented whenever feasible. If it cannot be prevented, it should be recycled. If it cannot be prevented or recycled, it should be treated and/or rendered non-polluting in an environmentally safe manner. Only as a last resort should pollution be disposed of or released into the environment.

State and Local Requirements. State and local regulatory agencies may require compliance with standards that may be more stringent than federal requirements. It is important for each installation to contact their state and local regulatory agencies for information on regulations and standards applicable to oil/water separators. This information can also be obtained by contacting the appropriate Headquarters Air Force Center for Environmental Excellence Regional Environmental Office (REO). A listing of the REOs and the geographical areas they cover can be obtained from the AFCEE World Wide Web site at http://www.afcee.brooks.af.mil.

Air Force Policy/Guidance
Air Force Instruction (AFI) 32-7041, Water Quality Compliance, 13 May 1994. In order to adequately protect surface water and groundwater quality, Section 2.10 of this AFI requires the application of certain criteria to normal O/WS operation and maintenance activities involving, for example, aircraft/vehicle maintenance, aircraft washing, fuel storage/transfer, fire training, storm water runoff and collection, and machine and paint shops. These criteria are:

• Perform regular inspections and maintenance of all oil/water separators to maintain water quality compliance;
• Use adequately sized oil/water separators to remove incidental releases of residual fuel, oil, grease, and other oily wastes when they cannot be otherwise managed using dry cleanup methods;
• Obtain a wastewater discharge permit (NPDES) for an oil/water separator when discharge to a wastewater treatment plant is not possible; and
• Do not discharge collected fuel, oil, grease, oily waste, solvents, cleaning compounds, or corrosion-control facility waste or other contaminants into oil/water separators.

Air Force Memorandum: Oil/Water Separators Operations, Maintenance and Construction, HQ USAF/CE Memorandum, 21 October 1994. This memorandum serves to highlight, and prohibit, the frequent improper use of the many hundreds of oil/water separators located at Air Force facilities. The perception that O/WSs provide an adequate level of treatment for pollutants other than free-floating petroleum products, as well as breakdowns in operation & maintenance procedures, has led to the potential for NPDES permit violations and serious liability and non-compliance problems. Attached to the memorandum is the document Environmental Compliance Policy for Oil/Water (O/W) Separators Operations, Maintenance, and Construction, which includes specific requirements designed to eliminate notices of violation (NOV) associated with O/WS discharges. This compliance policy contains the following specific requirements:

Existing Oil/Water Separators:

1. Develop and implement a plan for each base to assess the need for, and effectiveness of, existing oil/water separators with the goal of consolidation or elimination of ineffective units.
2. Perform a comprehensive inventory of all existing oil/water separators (including on-line oil and grease/fuel traps, and small oil/water separators outside of hangars, corrosion control facilities, fuels transfer/storage operations, Aerospace Ground Equipment (AGE) maintenance shops, wash racks, etc.). Identify all separators and the mode of discharge (such as to storm sewer, sanitary sewer, septic tank, or direct discharge to the waters of the U.S.).
3. Identify monitoring and discharge limits.
4. Locate the oil/water separator on the base utility as-built drawings and update the information as changes occur.

Operations and Maintenance:

1. Eliminate unpermitted pollutants and prohibit discharge of wastewater from industrial operations containing hazardous wastes and heavy metals.
2. Implement dry cleanup procedures and only use floor drains to carry residual amounts of floating petroleum pollutants. Plug floor drains to oil/water separators that carry industrial wastewater from maintenance shops. Collect, treat, and dispose of industrial waste separately.
3. Establish a primary office of responsibility (to include the functional organization for the management of pollutants discharged, and Civil Engineering for maintenance of oil/water separators) which understands and has direct control over respective functions.
4. Remove and test oil/water separator sludge regularly prior to disposal to ensure compliance with sludge disposal requirements. If the sludge is hazardous, take immediate actions to identify and eliminate sources of hazardous pollutants. Dispose of sludge as a hazardous waste and retest wastewater from oil/water separator to assure compliance.

Construction of Oil/Water Separators:
Do not build any new separators either through Real Property Maintenance (RPM) or Military Construction (MILCON) projects until completing an evaluation of the effectiveness of all existing oil/water separators and establishing a consolidation program. Install a double liner with leak detection system for new separators including associated oil recovery tanks. Do not build gravity separators for wastewater containing emulsified petroleum residuals, Aqueous Film Forming Foam (AFFF) releases, and other non-floating pollutants from industrial operations. Do not mix waste streams that are discharged to sewer systems; CWA and RCRA regulations prohibit discharges without the required level of treatment.

DRAFT AFI 32-7080, Compliance Assurance and Pollution Prevention (will revise existing AFI 32-7080, Pollution Prevention Program, 12 May 1994). Paragraph 4.3 of this DRAFT states that O/WSs are considered "compliance sites" and must be included in the installation's compliance site inventory. In addition, paragraph 3.5.2 states that efforts to achieve wastewater compliance will be focused on many factors, including the elimination/minimization of point sources such as O/WSs.

Engineering Technical Letter (ETL) 99-1: Treatment and Disposal of Aircraft Washwater Effluent, Headquarters Air Force Civil Engineer Support Agency (HQ AFCESA), 7 January 1999. This ETL provides technical criteria and guidance on the treatment and disposal of aircraft washwater effluent. It includes typical wastewater characteristics and specific guidance on selecting, procuring, and implementing treatment and recycling systems, including oil/water separators.

DRAFT Oil/Water Separator Guidance Manual, O/WS Ad Hoc Working Group, Department of Defense (DoD) CWA Steering Committee. This manual will incorporate and replace many of the guidance documents described above and listed below in that it will provide comprehensive guidance on all aspects of O/WS management, from determining whether or not an O/WS is needed, to proper selection, operation, and maintenance. A primary focus of the manual will be the discouragement of O/WS use in favor of implementing pollution prevention initiatives to eliminate the generation of oily wastewater discharges. Also included within the manual will be several flow diagrams that help guide readers through decision processes. Two of these diagrams, "Oil/Water Separator Decision" and "Oil/Water Separator Design," are included in this Fact Sheet as a separate reference tool. The Oil/Water Separator Guidance Manual is scheduled for release within the next 2 to 3 months, and copies will be available through the Defense Environmental Network Information Exchange (DENIX) or from PRO-ACT.

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Pollution Prevention
The Air Force is actively pursuing a policy of "compliance through pollution prevention." As such, it is requiring the use of pollution prevention solutions (e.g., waste-minimizing process changes and product substitutions) to modify or eliminate activities that have the potential to cause a violation of a federal, state, or local environmental law or regulation.

Installation industrial and maintenance activities should seek out and institute process changes that will eliminate the need for an oil/water separator. Floor drains in maintenance bays may not be necessary in all cases, particularly if a "dry" process can replace a "wet" process and eliminate a wastewater stream. If a drain is necessary, it should be protected against spills of non-petroleum products and/or large spills of petroleum products. It may be appropriate to connect the drain directly to a properly designed, installed, and maintained oil/water separator; or to an intermediary sump or holding pond/basin. If an existing oil/water separator is not needed, it should be removed to eliminate any potential liabilities and hazards associated with its improper use or abandonment.

Policies, guidelines, technologies, and process changes that can significantly reduce the Air Force's compliance burden associated with the use, and misuse, of oil/water separator units are contained in the documents listed below. Solutions range from the complete removal of an O/WS to improvements in their design, operation, and maintenance. It is important for base-level personnel to consult with their industrial/shop manager and/or unit environmental manager, and the installation environmental manager (EM/CEV) prior to commencing any modification, replacement, or removal of an O/WS. The installation EM/CEV will consult with the Bioenvironmental Engineer as necessary.

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General Considerations
O/WSs are typically very simple devices. However, several factors that could potentially affect safety, efficiency, and proper management must be given careful consideration prior to the installation or modification of any O/WS:

1. Flow Rate
   In general, the effectiveness of an O/WS in separating out the oil phase is increased by slower wastewater flow rates into the separator and longer "residence times" (i.e., the period of time that the wastewater remains in the oil/water separator). When the wastewater enters the receiving chamber of the separator, the velocity and turbulence of the fluid is reduced allowing heavier-than-water solids to settle, while the larger oil droplets rise to the water's surface. Further separation continues in the middle chamber (see Figure 1) where smaller droplets of oil rise (more slowly) to the water's surface and join the larger droplets. The resulting accumulated oil layer is diverted or "skimmed" to a separate holding area. The remaining wastewater, once it has passed under the second baffle to the outlet chamber, is discharged (with proper authorization and/or permitting) to a local stormwater or sanitary sewer system.
2. Design Capacity
   An O/WS has upper limits to the amounts of oil and sludge that can effectively accumulate while it is in operation. If too much oil accumulates in the receiving and middle chambers, it may flow into the wastewater outlet chamber and end up being discharged to the environment. Proper O/WS design will ensure the separator capacity is sized to meet the needs of the process.
3. Emulsifying Agents
   Detergents and soaps designed to remove oily grime from equipment, weapon systems, vehicles, or other components can adversely affect the operation of a gravity O/WS. These types of emulsifying agents are specifically formulated to increase the dispersal of oil into tiny drops in water, which is why they are such good cleaners. When these soapy wastewaters enter the O/WS, it takes significantly longer for the oil to separate, if it can, from the water. Excessive use of detergents can render an O/WS inefficient by completely emulsifying oils into the wastewater stream and allowing it to pass through the system. Low-emulsifying soaps are available that allow oil separation to occur more quickly after the soapy water enters the O/WS. (NOTE: Personnel must not use low-emulsifying soaps on weapon system components unless they are specifically approved by the weapon system's single manager.)
4. Maintenance Practices
   The ability of oil/water separators to function properly depends upon the timely performance of required service and maintenance. Oil/water separators must be monitored and maintained by competent personnel who understand how the systems operate. O/WSs should be given the same close attention given to any other important piece of equipment. The operators, users, and maintainers of the O/WS must clarify who will be responsible for monitoring, inspecting, maintaining, and servicing the system. Frequent inspections should be made of the system and all associated piping, valves, etc. to prevent operational and mechanical failures or inefficiencies. Sludges and oils that are not periodically removed from O/WSs can render it inoperative. Additionally, leaks from oil/water separators can result in environmental pollution, which can trigger costly investigative studies and cleanups. Rigorous implementation of an O/WS inspection and maintenance plan can prevent discharges from the oil/water separator that may contaminate the environment.
5. Suitablilty of O/WS System to Mission
   An oil/water separator designed and installed to meet a past mission requirement may no longer be suitable when mission requirements change and/or the original maintenance plan is no longer followed. An O/WS that is put to a use for which it was not originally designed may be damaged or may not function properly, and could become an environmental liability. For example, an oil/water separator designed to receive the wastewater discharge from a small fighter aircraft washrack will not be able to properly treat larger wastewater volumes from washing larger aircraft. Mission changes can also result in changes to the physical/chemical makeup of the wastewater being treated by an oil/water separator. Finally, mission changes may also necessitate the modification of stormwater and wastewater drainage systems. Such systems should remain separate from each other because excessive drainage of stormwater to an O/WS could significantly impair its operation and efficiency.

   The suitability of an O/WS system may be enhanced by placing it aboveground, which provides easier accessibility for maintenance and leak detection. Aboveground systems are also significantly less expensive to install than underground units. However, O/WSs require pumping of the wastewater from the area of the floor drain, possibly causing increased turbulence and less efficient separation. In addition, cold climates may pose a problem if the unit is exposed to the elements.

6. Contaminants Contained in the Wastewater Stream
   Metallic particles in the wastewater will settle into the sludge at the bottom of the O/WS. Solvents or fuel compounds may also be entrained in O/WS sludge. This sludge could require management under the Resource Conservation and Recovery Act (RCRA) as a hazardous waste if it exhibits certain toxicity characteristics. Therefore, it is important to prohibit the discharge of certain types of potential contaminants into an O/WS, and to regularly analyze sludge samples to determine toxicity prior to disposal. To reduce the accumulation of sludges, floors should be dry-swept before washing. General improvements in spill/drip control and containment of hazardous materials and oils will also reduce the amount of contamination in O/WS discharges.

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Reference Documents
There are a number of excellent reference documents that can assist installations with the design, installation, and maintenance of O/WSs. These documents are available on the World Wide Web (WWW) where indicated, or from PRO-ACT.

Waste Water Recycling and Pre-treatment Systems: An Alternative to Oil/Water Separators, Armstrong Laboratory, 1997. This report presents a comparison between conventional O/WSs and two other alternatives: a closed-loop wastewater recycling system and a sanitary sewer pre-treatment discharge system. Also provided are recommendations for implementing the concepts presented in the report, including installing recycling units, removing O/WSs, installing pre-treatment systems, plugging drains, and preventing discharges.

MIL-HDBK-1005/16, Wastewater Treatment System Design Augmenting Handbook, 31 October 1997. This handbook supplements commercial design guidance documents adopted by the military for use in designing wastewater treatment facilities at military installations. Section 5 of this handbook addresses military applications of oil/water separators, including determining need, design, and selection.

MIL-HDBK-1138, Wastewater Treatment System Operations and Maintenance Augmenting Handbook, 31 October 1997. This handbook augments the series of O&M field study training manuals prepared by California State University and the California Water Pollution Control Assoc. for the United States Environmental Protection Agency. The series has been adopted for use by the military and addresses most topics pertinent to wastewater treatment O&M.

Optimizing DoD Investments in Oil/Water Separators and Closed-Loop Recycle Treatment Systems, U.S. Army Environmental Center (USAEC), 1997. This guidance addresses the chronic problem of oil/water separators that are not properly designed and maintained. It evaluates and contrasts the traditional lower cost oil/water separators with higher cost closed-loop recycling units, which are far more protective of the environment.

ETL 1110-3-466, Selection and Design of Oil/Water Separators at Army Facilities, U.S. Army Corps of Engineers (USACE), 26 August 1994. This document contains information useful for planning, design, and construction of oil/water separators and appurtenances at U.S. Army facilities. The information is well organized and potentially applicable to any military installation.

Final Report of the Coalescing Tubes Test for Oil/Water Separators (O/WSs), U.S. Army Aberdeen Test Center, September 1998. This report compares the performance of the same O/WS unit both with and without oleophillic (oil "loving") coalescing tubes.

Oil/Water Separator Installation and Maintenance: Lessons Learned, U.S. Army Center for Public Works Technical Note, 31 October 1996. This document states that the military is one of the largest purchasers of oil/water separators in the U.S. It also discusses the fact that, in recent years, many of the oil/water separators installed by the military are not performing adequately due to problems with the design, selection, introduction of the wrong types of wastes, and lack of proper maintenance. As a first step toward confronting some of these issues, this document illustrates the most common problems associated with installing and operating oil/water separators at DoD installations.

Oil/Water Separation Technology User's Reference and Application Matrix. The purpose of the U.S. Army WWW site is to compile and organize O/WS-related information into a comprehensive, easy to use reference tool for installation personnel. It is organized into five sections: Overview, Application Matrix, Design Decision Tree, Common Questions & Problems, and a Search Engine. Visit this WWW site at http://aec-www.apgea.army.mil:8080/prod/usaec/et/ows/titlepage.htm.

In an effort to update and maintain environmental technology user requirements, the U.S. Army Environmental Requirements and Technology Assessments (AERTA) WWW site has been developed and is hosted on DENIX at http://www.denix.osd.mil/denix/DOD/Policy/Army/Aerta/default.html. Organizations with technology user requirements can benefit from the AERTA site, which shares lessons learned, potential technology solutions, and current research and development products that may solve their technology problem. Environmental Requirement No. A (2.2.e), Improve Oil and Grease Removal/Treatment Technologies for Contaminated Wastewaters and Sludges/Soils, contains links to many useful equipment vendor sites (skimmers, centrifuges, filters, coalescing units, etc.) and sources of more information for O/WS selection. This requirement is located at http://www.denix.osd.mil/denix/DOD/Policy/Army/Aerta/Need_assessment/A22e/a22e_a.html.

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For More Information . . .

• The video "Proper Operation and Maintenance of Oil Water Separators" was produced by the Headquarters Air Force Center for Environmental Excellence's Regional Environmental Office in Dallas (HQ AFCEE/CCR-D), and the Environmental Divisions of Headquarters Air Education and Training Command (HQ AETC/CEV) and Headquarters Air Force Reserve Command (HQ AFRC/CEV). It provides excellent instruction on the proper operation and maintenance of oil/water separators to installation personnel serving logistics, maintenance, and civil engineering functions. Copies of the video are available from PRO-ACT. As always, PRO-ACT is available to respond to questions from our eligible customers concerning oil/water separators. Contact us by telephone at DSN 240-4214 or by e-mail at pro-act@hqafcee.brooks.af.mil.
• Mr. Thomas Moreland, Environmental Quality Directorate, Headquarters Air Force Center for Environmental Excellence, (HQ AFCEE/EQ). Mr. Moreland is available to discuss Air Force projects and issues concerning storm water and wastewater pollution prevention. He can be reached by telephone at DSN 240-5303 or by e-mail at thomas.moreland@hqafcee.brooks.af.mil.
• The focus of the Wastewater Systems Program, Headquarters Air Force Civil Engineer Support Agency (HQ AFCESA/CESC) is to develop guidance and establish standards for the programming, design, construction, operation, maintenance, and revitalization of wastewater infrastructure and treatment systems. For more information, contact Mr. Myron Anderson, Program Manager, HQ AFCESA/CESC, DSN 523-6345 or Myron.Anderson@afcesa.af.mil. Visit the Waste Water Systems Program WWW site at http://www.afcesa.af.mil/Directorate/CES/Civil/WasteWtr/Wastewtr.htm, where you will be able to download some of the above-mentioned documents.
• Mr. Jay Shah, Environmental Division, Office of the Air Force Civil Engineer (HQ USAF/ILEVQ). Mr. Shah is available to discuss Air Force policy issues concerning O/WS including funding, installation, replacement, and removal. He can be reached by telephone at DSN 327-0120 or by e-mail at jayant.shah@pentagon.af.mil.

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Docurment References

1. Clean Water Act (CWA) (33 U.S.C. . 1251, et seq.), and administrative rules promulgated thereunder.
2. Oil Pollution Act (OPA) (33 U.S.C. . 2701, et seq.), and administrative rules promulgated thereunder.
3. Federal Facility Compliance Act (42 U.S.C. . 962, et seq.), and administrative rules promulgated thereunder.
4. Resource Conservation and Recovery Act of 1976 (RCRA) (42 U.S.C. . 6901, et seq.), and administrative rules promulgated thereunder.
5. Pollution Prevention Act (PPA) (42 U.S.C. . 13101, et seq.), and administrative rules promulgated thereunder.
6. Air Force Instruction (AFI) 32-7041, Water Quality Compliance, 13 May 1994.
7. Air Force Memorandum: Oil/Water Separators Operations, Maintenance and Construction, HQ USAF/CE Memorandum, 21 October 1994.
8. DRAFT AFI 32-7080, Compliance Assurance and Pollution Prevention (will revise existing AFI 32-7080, Pollution Prevention Program, 12 May 1994).
9. DRAFT DoD Oil/Water Separator Guidance Manual, June 1999.
10. Engineering Technical Letter (ETL) 99-1: Treatment and Disposal of Aircraft Washwater Effluent, Headquarters Air Force Civil Engineer Support Agency (HQ AFCESA), 7 January 1999.
11. Waste Water Recycling and Pre-treatment Systems: An Alternative to Oil/Water Separators, Armstrong Laboratory, 1997.
12. MIL-HDBK-1005/16, Wastewater Treatment System Design Augmenting Handbook, 31 October 1997.
13. MIL-HDBK-1138, Wastewater Treatment System Operations and Maintenance Augmenting Handbook, 31 October 1997.
14. Optimizing DoD Investments in Oil/Water Separators and Closed-Loop Recycle Treatment Systems, U.S. Army Environmental Center (USAEC), 1997.
15. ETL 1110-3-466, Selection and Design of Oil/Water Separators at Army Facilities, U.S. Army Corps of Engineers (USACE), 26 August 1994.
16. Final Report of the Coalescing Tubes Test for Oil/Water Separators (O/WSs), U.S. Army Aberdeen Test Center, September 1998.
17. A Decision Tree for Improving Washrack Oil/Water Separator Operations, USAEC, January 1998.
18. Oil/Water Separator Installation and Maintenance: Lessons Learned, U.S. Army Center for Public Works Technical Note, 31 October 1996.
19. Oil/Water Separation Technology User's Reference and Application Matrix, http://aec-www.apgea.army.mil:8080/prod/usaec/et/ows/titlepage.htm.
20. U.S. Army Environmental Requirements and Technology Assessments (AERTA) WWW site, http://www.denix.osd.mil/denix/DOD/Policy/Army/Aerta/default.html.
21. Environmental Requirement No. A (2.2.e), Improve Oil and Grease Removal/Treatment Technologies for Contaminated Wastewaters and Sludges/Soils, http://www.denix.osd.mil/denix/DOD/Policy/Army/Aerta/Need_assessment/A22e/a22e_a.html.