2008 Final OWS Management Plan_Redacted for reference.pdf

FINAL

OIL/WATER SEPARATOR MANAGEMENT PLAN

DYESS AIR FORCE BASE, TEXAS

Prepared For:

HQ ACC/A7VQ

129 Andrews Street, Suite 102 Langley AFB, Virginia 23665

Prepared By:

URS Group, Inc.

1600 Perimeter Park Drive

Morrisville, North Carolina 27560

July 2008

ECAS Contract No. FA4890-04-D-0005 Task Order No. 5015

Oil/Water Separator Management Plan Dyess AFB, Texas

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TABLE OF CONTENTS

EXECUTIVE SUMMARY .................................................................................................... ES-1

1.0 INTRODUCTION ......................................................................................................... 1-1

1.1 Installation Description........................................................................................1-1

1.2 Project Background..............................................................................................1-2

1.3 Objectives ............................................................................................................1-2

1.4 Report Organization.............................................................................................1-3

2.0 RELEVANT REGULATORY REQUIREMENTS.................................................... 2-1

2.1 Federal Environmental Regulations.....................................................................2-1

2.1.1 Clean Water Act and the NPDES Program..............................................2-1

2.1.2 Oil Pollution Act and the SPCC Program................................................2-2

2.1.3 Solid Waste Disposal Act ........................................................................2-2

2.1.4 Resource Conservation and Recovery Act ..............................................2-2

2.1.5 Pollution Prevention Act..........................................................................2-3

2.2 Department of Defense Requirements and Guidance..........................................2-4

2.2.1 Department of Defense Requirements .....................................................2-4

2.2.2 Department of Defense Guidance............................................................2-7

2.3 State and Local Requirements .............................................................................2-8

2.3.1 State Regulations .....................................................................................2-8

2.3.2 Local Wastewater Regulations ................................................................2-9

2.3.3 Storm Water Discharge Permit ................................................................2-9

3.0 METHODOLOGY ........................................................................................................ 3-1

3.1 Records Review ...................................................................................................3-1

3.2 Field Survey .........................................................................................................3-1

3.3 Data Management ................................................................................................3-2

3.4 Decision Logic and Design Criteria.....................................................................3-2

4.0 OIL/WATER SEPARATOR INVENTORY RESULTS............................................ 4-1

5.0 RECOMMENDATIONS............................................................................................... 5-1

5.1 Recommended Action 1: Install OWS and SI .....................................................5-1

5.2 Recommended Action 2: Repair OWSs ..............................................................5-1

5.3 Recommended Action 3: Eliminate Unnecessary OWSs ....................................5-2

5.4 Recommended Action 4: Implement Miscellaneous Repairs..............................5-2

5.5 Recommended Action 5: Construct Compliant and Operable Wash Racks........5-3

5.6 Other Recommendations......................................................................................5-4

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TABLE OF CONTENTS (Continued)

6.0 BUDGETARY COST ESTIMATE.............................................................................. 6-1

6.1 Basis of Estimate..................................................................................................6-1

6.2 Cost Estimating Assumptions ..............................................................................6-2

6.3 Cost Estimate Summary.......................................................................................6-3

7.0 REFERENCES............................................................................................................... 7-1

APPENDICES

APPENDIX A BLANK OIL/WATER SEPARATOR SURVEY FORM

APPENDIX B OIL/WATER SEPARATOR AND SAND INTERCEPTOR INVENTORY

RESULTS AND RECOMMENDATIONS

Oil/Water Separator and Sand Interceptor Inventory Summary Oil/Water Separator and Sand Interceptor Recommendation Summary Oil/Water Separator and Sand Interceptor Detailed Inventory Summary Sheets

APPENDIX C OIL/WATER SEPARATOR AND SAND INTERCEPTOR LOCATION

MAP

APPENDIX D NON-OWS INDUSTRIAL FACILITY RECOMMENDATIONS AND

SUMMARY SHEETS

Non-OWS Industrial Facility Recommendations Non-OWS Industrial Facility Summary Sheets

APPENDIX E OIL/WATER SEPARATOR OPERATION AND MAINTENANCE

MANUAL

APPENDIX F COST ESTIMATES

Recommended Action Cost Summary Oil/Water Separator Project Unit Costs Detailed Cost Estimates

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LIST OF TABLES

Table ES-1. Summary of OWS and SI Inventory.................................................................... ES-1 Table ES-2. Dyess AFB Recommendation Summary and Estimated Cost ............................. ES-2

Table 3-1. Rationale for OWSs at ACC Facilities...................................................................... 3-7 Table 3-2. Oil/Water Separator Design Criteria ....................................................................... 3-16

Table 4-1. OWS and SI Inventory Summary.............................................................................. 4-1 Table 4-2. OWS and SI Inventory .............................................................................................. 4-2

Table 5-1. Summary of Recommended Action 1: Install OWS and SI ..................................... 5-1 Table 5-2. Summary of Recommended Action 3: Eliminate Unnecessary OWSs and SIs....... 5-2 Table 5-3. Summary of Recommended Action 4: Implement Miscellaneous Repairs ............. 5-3 Table 5-4. Summary of Recommended Action 5: Construct Compliant and Operable

Wash Racks .............................................................................................................. 5-3 Table 5-5. Summary of Other Recommendations ..................................................................... 5-4

Table 6-1. Cost Summary for Recommended Actions ............................................................... 6-4

LIST OF FIGURES

Figure 1-1. Site Location, Dyess AFB, Texas ............................................................................. 1-1

Figure 3-1. OWS Recommendation Decision Flow Chart .......................................................... 3-3

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LIST OF ABBREVIATIONS AND ACRONYMS

A7VQ Civil Engineer Environmental Compliance ACC Air Combat Command ACCMAN Air Combat Command Manual AFB Air Force Base AFFF Aqueous film forming foam AFI Air Force Instruction AFM Air Force Manual AGE Aerospace ground equipment AMC Air Mobility Command API American Petroleum Institute BMP Best management practice CE Civil Engineer CEOI Civil Engineer Operations Infrastructure CEV Civil Engineer Environmental CFR Code of Federal Regulations CWA Clean Water Act DoD Department of Defense ECAS Environmental Compliance and Analysis Services EPA Environmental Protection Agency ETL Engineering Technical Letter FOTW Federally owned treatment works FY Fiscal year GC Grit chamber GOV Government owned vehicle GSU Geographically separate unit HQ Headquarters IAPMO International Association of Plumbing and Mechanical Officials IPC International Plumbing Code mg/L Milligrams per liter MIL-HDBK Military Handbook N/A Not applicable NDI Non-destructive inspection NPDES National Pollutant Discharge Elimination System O&M Operation and maintenance O/W Oil/water OPA Oil Pollution Act OWS Oil/water separator P2 Pollution prevention PCB Polychlorinated biphenyl POL Petroleum, oil, and lubricants POTW Publicly owned treatment works POV Privately owned vehicle PPA Pollution Prevention Act

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LIST OF ABBREVIATIONS AND ACRONYMS (Continued) ppm Parts per million RCRA Resource Conservation and Recovery Act ROM Range of magnitude SI Sand interceptor SIOH Supervision, inspection, and overhead SPCC Spill Prevention, Control, and Countermeasure SWDA Solid Waste Disposal Act TPDES Texas Pollutant Discharge Elimination System TPH Total petroleum hydrocarbons UFC Unified Facilities Criteria UPC Uniform Plumbing Code URS URS Group, Inc.

USAF United States Air Force UST Underground storage tank WWTP Wastewater treatment plant

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EXECUTIVE SUMMARY

Oil/water separators are commonly used on Department of Defense (DoD) installations as a method to separate oils from a variety of storm water and wastewater discharges. This Oil/Water Separator Management Plan summarizes the results of the oil/water separator (OWS) survey conducted in July 2006 at Dyess Air Force Base (AFB) by URS Group, Inc. The goals of this project were to identify necessary improvements to the OWS units and OWS management program at Air Combat Command (ACC) installations; to evaluate their compliance with the Clean Water Act and all related state, local and U.S. Air Force regulatory requirements; and to assist in identifying ways to reduce the cost of maintaining OWSs. The recommendations and cost estimates in this report can serve as a useful planning and programming tool that the base can use to achieve and maintain compliance with their OWS program.

This OWS and industrial facility assessment provides Dyess AFB with (1) an overview of applicable regulatory requirements for OWS operation and maintenance; (2) a complete inventory of the OWSs and sand interceptors (SIs) on the base; (3) a listing of installation, repair, replacement, and elimination recommendations; and (4) budgetary cost estimates for implementing the recommendations.

Table ES-1 provides a summary of the OWS and SI inventory results. A total of 47 suspected industrial facilities (32 non-OWS facilities and 15 OWS/SI facilities) were surveyed at Dyess AFB during the fieldwork. A total of 14 OWS units and 3 SIs were located and surveyed. Two of the OWS units surveyed were found to be inactive.

Table ES-1. Summary of OWS and SI Inventory

Unit Type Active Inactive Total Oil/Water Separators 12 2 14 Sand Interceptors 3 0 3

Approximately one-half of the OWSs at Dyess AFB are not necessary. In addition, some of the necessary units require repair. Recommendations to repair or improve the operation of inadequate OWSs and SIs are included in this plan, as well as recommendations to eliminate unnecessary units. Recommendations are also made to provide compliant and operable wash racks. The range of magnitude cost to implement these recommendations is approximately

Funding and implementation of all recommendations will likely be conducted in phases; therefore, the recommendations have been divided into five smaller recommended actions. A summary of recommended actions and estimated costs is presented in Table ES-2.

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Table ES-2. Dyess AFB Recommendation Summary and Estimated Cost

Recommended Action

Number of Facilities / Units

Addressed 1 Total Estimated

Cost2, 3

Recommended Action 1: Install an OWS and SI.

Recommended Action 2: Repair alarms on OWSs.

Recommended Action 3: Eliminate OWS units determined unnecessary for facility operations. Implement pollution prevention measures and structural modifications to eliminate future discharge from associated facilities.

Recommended Action 4: Implement miscellaneous repairs on valves or lift stations associated with OWSs and reroute storm water discharges to the storm drainage system.

Recommended Action 5: Construct or modify compliant and operable wash racks.

Other Recommendations: Implement miscellaneous recommendations pertaining to industrial facilities.

Total:

1 Recommendations include all industrial facilities surveyed, including those facilities with and without OWSs and/or SIs. Some facilities are included in multiple recommended actions.

2 Costs do not include fee for engineering design and consulting services.

3 Costs assume that construction will take place in Fiscal Year 2009. If construction takes place further out, escalation will need to be increased.

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1.0 INTRODUCTION

This Oil/Water Separator Management Plan has been prepared by URS Group, Inc. (URS) in response to ECAS Contract No. FA4890-04-D-005, Task Order No. 5015, at the request of Headquarters (HQ) Air Combat Command (ACC). This Management Plan incorporates information gathered during the oil/water separator (OWS) survey conducted at Dyess Air Force Base (AFB) from 10–19 July 2006 by URS personnel. The plan provides an inventory of existing OWSs on base; process descriptions for industrial facilities without existing OWSs; and recommendations and cost estimates for installation, continued operation, elimination, or upgrading and proper operation and maintenance (O&M) of OWSs and sand interceptors (SIs).

The scope of work for this project includes an evaluation of OWSs, grease interceptors, and septic systems; however, this report incorporates only OWS and industrial facility information gathered during the survey. A Grease Interceptor Management Plan is provided under separate cover. There are no septic systems at Dyess AFB.

1.1 Installation Description

Dyess AFB is located in the northeast corner of Taylor County, Texas and occupies over 6,000 acres just west of Abilene. The base was established in 1956 as Abilene Air Force Base. Later that same year, the base was renamed Dyess Air Force Base after Lt Col William Edwin Dyess, a decorated Air Force pilot from Texas. A site location map is presented as Figure 1-1.

Dyess AFB hosts the 7th Bomb Wing, which operates B-1 Bombers. The base also supports the 7th Operations Group, the 7th Mission Support Group, the 7th Maintenance Group, and the 7th Medical Group. The main tenant organization is the 317th Airlift Group, which is under Air Mobility Command (AMC). This organization operates C-130 aircraft in support of missions worldwide.

The total population of the base is approximately 7,180, comprised of approximately 5,370 military personnel, 1,030 dependents living on base, as well as an estimated 780 civilian non-residents that commute to the base daily. All of the domestic and industrial wastewater at the base is discharged to the City of Abilene where it is treated at the City of Abilene Wastewater Treatment Plant (WWTP).

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1.2 Project Background

Oil/water separators are commonly used on Department of Defense (DoD) installations as a method to separate oils from a variety of storm water and wastewater discharges. Properly designed, installed, and operated OWSs provide a treatment system for handling oily wastewater that prevents the entry of unacceptable levels of contamination to the storm drainage or sanitary sewer system. In recent years, many U.S. Air Force installations observed that their OWSs are not required for the functional activities they serve and that many of the OWSs could be eliminated and replaced by pollution prevention (P2) measures. In addition, many required OWSs have been used incorrectly and/or are not adequately treating the storm water or wastewater sources.

1.3 Objectives

The following objectives related to OWSs and industrial facilities were established for this project:

• Inventory OWSs located on main operating bases; facilities located at geographically separate units (GSUs) are not included in this project

• Survey each facility that may be generating and discharging industrial wastewater into the storm water drainage system, sanitary sewer, or septic systems

• Characterize wastewater-generating activities and types and volumes of wastes that contribute to each unit (OWS or grease interceptor ) or discharge directly into the storm water drainage system, sanitary sewer, or septic systems

• Determine the discharge location (i.e., sanitary sewer or storm drainage system) of each pretreatment unit

• Evaluate the structural and operational condition of each pretreatment unit, and determine whether the design is adequate for the type and volume of wastewater being discharged to each

• Evaluate the existing pretreatment unit O&M practices and related P2 best management practices (BMPs), and determine if these are adequate to ensure fully compliant and effective operation

• Identify units that require repairs, should be replaced, or are no longer needed and should be eliminated

• Develop 10% conceptual designs and range of magnitude (ROM) cost estimates for all structural recommendations

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• Develop a database that can be used as an operation, maintenance, and management tool for OWSs

1.4 Report Organization

The remainder of this report is organized as follows:

• Section 2: A summary of the regulatory requirements for OWSs at Dyess AFB

• Section 3: A description of the methodology used in completing the survey, including preliminary records review, field survey, data management, decision logic, and design criteria

• Section 4: The results of the OWS system survey and inventory

• Section 5: Recommendations for OWS installation, elimination, repair, or replacement

• Section 6: The budgetary cost estimate for implementing the recommendations in this report

• Section 7: References used in developing this report

These sections are supported by the following appendices:

• Appendix A provides a blank OWS survey form.

• Appendix B includes the OWS inventory results and recommendations, including detailed inventory sheets and facility sketches.

• Appendix C provides a map of the sanitary sewer system, illustrating OWS and SI locations.

• Appendix D includes the recommendations and summary sheets for those industrial facilities surveyed that do not have an existing OWS.

• Appendix E contains an OWS O&M Manual for Dyess AFB.

• Appendix F provides supporting information for the recommended action cost estimates.

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2.0 RELEVANT REGULATORY REQUIREMENTS

Regulations and guidance applicable to OWS compliance at Dyess AFB fall under three main categories: federal environmental regulations, DoD requirements and guidance, and state and local requirements. Each relevant regulation and guidance document has been reviewed and summarized below. This information was used to guide the recommendation process for each OWS and industrial facility surveyed at Dyess AFB.

2.1 Federal Environmental Regulations

The main federal environmental program related to OWS systems are encompassed by the Clean Water Act (CWA) and its applicable regulatory program, the National Pollutant Discharge Elimination System (NPDES) program. OWSs are also subject to the Oil Pollution Act (OPA) and its applicable regulatory program, the Spill Prevention, Control, and Countermeasure (SPCC) program. Other regulations, such as the Solid Waste Disposal Act (SWDA), Resource Conservation and Recovery Act (RCRA), underground storage tank (UST) regulations, and the Pollution Prevention Act (PPA) are also applicable. All of these programs are briefly discussed in this section.

2.1.1 Clean Water Act and the NPDES Program

Under the CWA, the NPDES permit program regulates the quality of point-source wastewater discharges and storm water associated with industrial activities that discharges into waters of the U.S. Some of these activities include storm drainage and sanitary sewer systems on DoD installations, federally owned treatment works (FOTW), or publicly owned treatment works (POTW). Various storm water and wastewater management programs are required by facilities that are permitted under the NPDES program to prevent or minimize the discharge of pollutants.

Facilities that do not hold NPDES permits but indirectly discharge storm water or wastewater to NPDES permitted facilities may also be impacted by these requirements, including industrial facilities. In order to discharge to a local sanitary sewer system, generators must demonstrate compliance with pretreatment standards as mandated by the WWTP operator. The WWTP is ultimately responsible for the quality of their NPDES-permitted discharge and may place restrictions on the indirect dischargers within their system to ensure compliance. Thus, the CWA requires POTWs to develop local limits for discharges of non-domestic wastewater to the collection system. Although FOTWs are not required by the CWA to develop local limits, facilities that indirectly discharge to FOTWs do have a responsibility to ensure that their discharge does not cause the FOTW to exceed its NPDES permit limits.

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Regulations related to indirect discharges are codified within Title 40 of the Code of Federal Regulations (CFR) Part 403, General Pretreatment Regulations. Discharges to a sanitary sewer system from OWSs may require monitoring for oils and greases, total organic compounds, total suspended solids, and other parameters in order to ensure compliance with established limits.

Industrial and commercial dischargers of high strength wastewater could cause the WWTP to exceed their discharge standards.

2.1.2 Oil Pollution Act and the SPCC Program

Parties responsible for a facility from which oil is discharged or that poses a substantial threat of an oil discharge to surface waters are held liable by the OPA for damages to the environment and any required corrective action. Regulations promulgated under the OPA pertinent to OWSs include 40 CFR 110, Discharge of Oil, and 40 CFR 112, Oil Pollution Prevention and Response, which establishes requirements for the preparation and implementation of SPCC plans. Separate waste oil holding tanks associated with an OWS may be regulated by SPCC requirements.

2.1.3 Solid Waste Disposal Act

The SWDA regulates the disposal of solids from OWSs. Title 40 CFR 258.20, Criteria for Municipal Solid Waste Landfills, specifies restrictions on the types of material that can be placed in landfills, including regulated hazardous waste, polychlorinated biphenyl (PCB) waste, and “free liquids.”

When OWSs are cleaned and the contents are disposed of, samples of the solid and liquid phases must be collected and analyzed to determine the waste characterization and facilitate proper disposal measures. Alternatively, generator knowledge may be used to determine applicable disposal options. Depending on the source(s) of flow and contaminant loading, the removed material may be hazardous, requiring special disposal measures. The organization responsible for cleaning OWSs is required to follow these regulations.

2.1.4 Resource Conservation and Recovery Act

Resource Conservation and Recovery Act, 40 CFR 261, Subpart C, Hazardous Waste Management, establishes the requirements to regulate and control the generation, treatment, storage, transportation, and disposal of solid and hazardous wastes. RCRA also establishes requirements to regulate USTs containing certain substances, including oil and hazardous wastes.

Liquids and sludge contained in OWSs are regulated under 40 CFR 261, Subpart C if generator knowledge and/or analytical analyses indicate the material is characteristically hazardous or under Subpart D if it is a listed hazardous waste.

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The oil removed by an OWS is considered “used oil.” The U.S. Environmental Protection Agency (EPA) classifies used oil into three categories: on-specification used oil, off-specification used oil, and hazardous waste fuel. If the used oil contains more than 1,000 parts per million (ppm) of total halogens, U.S. EPA considers the oil a hazardous waste. This oil is subject to hazardous waste regulations, including the burning of hazardous waste as fuel. If the oil contains less than 1,000 ppm of total halogens, it is regulated under 40 CFR 279, Standards for the Management of Used Oil. To determine if the used oil is considered on- or off-specification, further analyses must be performed. Off-specification used oil must meet all requirements of 40 CFR 279 regardless of the disposal/recycling method (reuse, energy recovery, disposal). If on-specification used oil is to be burned for energy recovery, it can be exempted from many of the requirements of 40 CFR 279. However, if on-specification used oil is to be reused or disposed, it must meet all requirements of 40 CFR 279.

RCRA also contains requirements for USTs under 40 CFR 280, Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks.

These standards cover tank design, operation, cleanup, and closure. In general, OWSs are either excluded or deferred from the UST regulations under one of the following provisions:

• as field constructed tanks and/or

• as wastewater treatment tank systems subject (or not subject) to sections 307(b) and 402 of the CWA.

Many OWS systems are equipped with separate used oil underground holding tanks that are subject to UST regulations. Any such underground holding tank must be permitted by the state UST program, and in the event of closure, applicable UST closure procedures must be followed.

It should be noted that the states of Maryland and North Carolina have recently changed their stance on OWSs and may be incorporating OWSs into their UST program. Other states including Texas may similarly revise the UST regulations to incorporate OWSs in the future.

2.1.5 Pollution Prevention Act

The PPA makes P2 the national policy of the U.S. 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 the pollutant cannot be prevented or recycled, it should be treated and/or rendered non-polluting in an environmentally safe manner. By eliminating unnecessary discharges and OWSs, and by properly using and maintaining the units that remain in service, the pollutant loading to the sanitary sewer and storm water drainage systems at Dyess AFB will be decreased.

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2.2 Department of Defense Requirements and Guidance

Various DoD memoranda, instructions, and manuals establish military policy and provide guidance for OWS management. The following sections summarize relevant DoD requirements and guidance documents.

2.2.1 Department of Defense Requirements

The following documents represent past and current DoD policy requirements related to OWS management and are summarized in this section:

• HQ USAF/CE Memorandum (1994): Oil/Water Separators Operation, Maintenance, and Construction

• ACC Manual (ACCMAN) 32-7051 (2002), Environmental Quality Manual

• Air Force Instruction (AFI) 32-7041 (2003), Water Quality Compliance

• ACC Wastewater System Standards and Assessments (2004)

• Draft Final HQ ACC Oil/Water Separator Management Policy (2008)

HQ USAF/CE Memorandum (1994)

The HQ USAF/CE memorandum alerts the U.S. Air Force environmental community to the compliance liability associated with improperly operated and maintained OWSs. It states:

“These separators have created a false sense of security among people in the field, leading to a belief that O/W separators provide an adequate level of treatment/removal of many types of pollutants being discharged…. As a consequence, inadequate operations and maintenance, along with unauthorized discharges of wastewater containing industrial pollutants through O/W separators, have the potential of creating serious liability and non-compliance problems throughout the Air Force” (HQ USAF/CE, 1994).

Attached to this memorandum is an Environmental Compliance Policy that requires that the DoD, including the Air Force, complete the following actions:

• Develop a program to assess the need for and effectiveness of existing OWSs; ensure proper operation, maintenance, and compliance monitoring of required OWSs; and eliminate unnecessary OWSs

• Assign primary responsibility for OWS management to a specific base-level office

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• Eliminate unauthorized discharges to OWSs and establish and implement P2 BMPs to minimize discharge of oily wastes, including plugging floor drains that discharge industrial wastewater to OWSs when possible

• Ensure proper testing and disposal of sludge and oils removed from OWSs

• Avoid the installation of new OWSs whenever possible

This memorandum was superseded by AFI 32-7041.

ACCMAN 32-7051 (2002)

ACCMAN 32-7051 provides policy and guidance for ACC installations to ensure compliance with applicable environmental regulations. This document incorporates the 1994 OWS Memo and Environmental Compliance Policy discussed above and provides an outline to assist with implementation of the policy statements. It also includes a table of typical Air Force facilities and the pretreatment required for each, as well as a flow chart to assist in making decisions about the installation and/or removal of OWS systems.

AFI 32-7041 (2003)

AFI 32-7041 provides details of the Air Force Water Quality Compliance Program, the goal of which is to comply with applicable environmental regulations to adequately protect surface water and groundwater quality. This AFI supersedes the OWS Policy provided in the two previously discussed documents, the Environmental Compliance Policy (1994) and applicable sections of ACCMAN 32-7051 (2002). Section 2.10 of AFI 32-7041 addresses OWS installation, operation, and maintenance and requires that all Air Force installations perform the following actions:

• Evaluate all alternatives, including the implementation of P2 BMPs, before installing new OWSs

• Perform a survey to locate, assess the need for, and identify opportunities to eliminate existing OWSs

• Eliminate unauthorized discharges to OWSs and establish and implement P2 BMPs to minimize discharge of oily wastes, including plugging floor drains that discharge industrial wastewater to OWSs when feasible

• Eliminate the discharge of collected fuel, oil, grease, oily waste, solvents, cleaning compounds, corrosion-control facility waste or other contaminants into OWSs

• Discontinue the use of OWSs as containment devices

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• New OWSs and associated oil recovery tanks, installed belowground, must be installed over a double liner or have double walls with a leak detection system

• Perform regular inspections and maintenance of all OWSs to maintain water quality compliance

• Obtain a wastewater discharge permit (NPDES) for an OWS when discharge to a wastewater treatment plant is not possible

ACC Wastewater System Standards and Assessments (2004)

ACC Wastewater System Standards and Assessments, in combination with AFI 32-7041, provides ACC policy for OWS installation and maintenance. It includes requirements given in previous policy documents and adds the following:

• Provide pretreatment of required industrial waste flows as close to the source as possible

• Upgrade OWSs in accordance with the following: American Petroleum Institute (API) Publication 421, Design and Operation of Oil/Water Separators (February 1990); Engineering Technical Letter (ETL) 1110-3-466, Engineering and Design:

Selection and Design of Oil/Water Separators at Army Facilities; and Military Handbook (MIL-HDBK) 1138/ Unified Facilities Criteria (UFC) 3-240-03N, Wastewater Treatment System Operations and Maintenance Augmenting Handbook (October 1997/January 2004)

• Underground units must have secondary containment and shall protrude above the ground surface a minimum of 8" to prevent storm water intrusion. Steel tanks shall have cathodic protection

• Underground OWSs shall be an “open type unit” with removable grates or covers for easy access for maintenance

Covers should be easily removable by no more than two workers

Removal of covers shall expose a minimum of 50% of wet surface area

• Mechanical components should be kept to a minimum

• If parallel plate separators are required, they should be designed with cross flow parallel plates. Parallel plates will increase the surface area of the separator providing additional removal of oil; however, they must be cleaned regularly to function properly

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Minimum spacing for inclined plates is ¾"

The angle of inclination of the plate shall be 55 degrees from horizontal

• Storm water inflow will be eliminated to the maximum extent practical for all OWSs discharging to the sanitary sewer system

• Conveyance of oily wastewater to the separator shall be by gravity or where site conditions require pumping only progressive cavity pumps, or other low shear pumps will be used. Centrifugal pumps will not be used

• The separator inlet shall include a distribution header designed to reduce turbulence

Draft Final HQ ACC Oil/Water Separator Management Policy (2008)

As part of this task order, URS assisted HQ ACC with the development of a Draft Final Oil/Water Separator Management Policy. The purpose of this policy is to provide comprehensive instructions for the management, application, installation, elimination, and O&M of OWSs. In addition, the policy will ensure that ACC installations use uniform reasoning to determine whether or not a facility requires an OWS. Attached to the policy is a supplement which provides guidelines to assist installations with policy implementation.

2.2.2 Department of Defense Guidance

The following documents provide design and O&M guidance related to OWSs and are summarized in this section:

• Multiservice Oil/Water Separator Guidance Manual (U.S. Air Force, 1999)

• UFC 3-240-02N (2004), Design: Wastewater Treatment System Augmenting Handbook (MIL-HDBK 1005/16)

• UFC 3-240-03N (2004), Wastewater Treatment Systems Augmenting Handbook Operations and Maintenance (MIL-HDBK 1138)

Multiservice Oil/Water Separator Guidance Manual (1999)

The Multiservice Oil/Water Separator Guidance Manual (U.S. Air Force, 1999) provides guidance for all military facilities to properly assess and manage their OWS and grease interceptor systems. This document reflects DoD philosophy regarding OWSs that is discussed in the previously mentioned memorandum and instructions. Detailed information on all aspects of OWS assessment, management, selection, and elimination are contained in this resource.

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UFC 3-240-02N and UFC 3-240-03N (2004)

UFC 3-240-02N includes general design criteria pertinent to wastewater treatment systems and incorporates a revised version of MIL-HDBK 1005/16. This UFC supersedes the version of MIL-HDBK 1005/16 published in 1999. This document provides guidance for OWS evaluation, design, application and O&M, as well as background information on principles of separation and technology options.

UFC 3-240-03N incorporates a revised version of MIL-HDBK 1138 and supersedes the previous version published in 1997. It includes information similar to that provided by UFC 3-240-03N discussed above, but with more of an emphasis on the O&M of wastewater treatment systems.

2.3 State and Local Requirements

In addition to federal and DoD requirements and guidance, all facilities are required to comply with any applicable state or local regulations. State regulations applicable to Dyess AFB are located in Title 8, Chapter 1301 of the Texas Occupations Code. In addition, the base must comply with Chapter 32, Article III of the Abilene Code of Ordinances. The base must also comply with storm water regulations as outlined in their Texas Pollutant Discharge Elimination System (TPDES) permit which authorizes the base to discharge storm water from industrial areas. These state and local regulations are discussed in this section.

2.3.1 State Regulations

Title 8, Chapter 1301, Section 255 of the Texas Occupations Code, Adoption of Plumbing Codes adopts the Uniform Plumbing Code (UPC) and the International Plumbing Code (IPC). Chapter 10 of the UPC provides requirements for sizing and installing OWSs. OWSs are required at repair garages and gasoline stations with grease racks or pits. The OWS must be rated (using the manufacturer’s rating) equal to or greater than the incoming flow and have an overflow line to an underground tank. When a manufacturer rating is not available for a unit, a sizing formula is provided that incorporates the service bay surface area. Grit (or sand) interceptors are required at automobile wash racks, and a formula is provided for sizing the inlet and outlet sections of the unit.

Similar to the UPC, Chapter 10 of the IPC provides requirements for sizing and installing OWSs and grit (or sand) interceptors. Oil/water separators are required at repair garages, car washing facilities with engine or undercarriage cleaning capability, and any other facility that could discharge oil-bearing waste to the collection system. An OWS sizing formula is provided that incorporates the service bay surface area. Grit (or sand) interceptors are required to be designed

July 2008 2-9 Final and located so as to be readily accessible for cleaning and maintenance, but there are no detailed requirements for installation or sizing.

2.3.2 Local Wastewater Regulations

The base is required to comply with Chapter 32, Article III of the Abilene Code of Ordinances.

Section 32-59 of the ordinance, Pretreatment requires that OWSs meet the requirements of the City Plumbing Code which adopts the IPC (as described in Section 2.3.1 above). The ordinance prohibits the discharge of petroleum oil in amounts that will cause interference or pass through, or total petroleum hydrocarbons (TPH) exceeding 167 pounds per day. A surcharge fee is assessed for those facilities that discharge TPH in excess of 20 milligrams per liter (mg/L).

2.3.3 Storm Water Discharge Permit

Storm water discharge from industrial areas at Dyess AFB is permitted under the Multi Sector TPDES General Permit TXR050000, issued on 14 August 2006. Storm water at the base is discharged to Lake Fort Phantom via two outfalls. Quarterly visual monitoring at the outfalls must document the presence/absence of an oil sheen among other parameters. The permit also requires that a maintenance program for structural controls such as OWSs be developed and described in the Storm Water Pollution Prevention Plan.

July 2008 3-1 Final

3.0 METHODOLOGY

A primary objective of this study was to inventory all OWSs at Dyess AFB. This inventory was a prerequisite to making the appropriate recommendations for each unit based on applicable regulations and appropriate DoD guidance. Inventory data was collected to determine which OWSs were being utilized in a manner compliant with applicable regulations and, ultimately, which units should remain in service or be eliminated, repaired, or replaced. The following sections describe the preliminary records review, field survey, data management, decision logic, and design criteria used in the unit inventory and evaluation process.

3.1 Records Review

Prior to mobilizing for fieldwork, URS gathered preliminary data to develop a target list of known or suspected OWSs that would be inspected. Information gathered during this task included historical OWS lists, reports, and maps of the base sanitary sewer and storm water drainage systems. The Dyess AFB real property list was also reviewed to identify shops and industrial activities that could require the use of OWSs. This information was used to develop a preliminary list of suspected and previously identified units to be inspected.

3.2 Field Survey

URS surveyed 47 industrial facilities at Dyess AFB from 10–19 July 2006. These facilities were selected based on the list created during the records review phase. Field work was conducted by two (2) teams of two (2) individuals each. Each team used customized field survey forms for documentation of relevant data during the survey process. A blank copy of the OWS field survey form used in this effort is provided in Appendix A.

Typically, when inspecting a facility for an OWS, the team would enter the facility to identify a point of contact and to gather information about facility activities, storm water or wastewater sources, chemical usage, and existing P2 methods. The team then surveyed the surrounding area to confirm the presence or removal of known or suspected OWSs and to identify any additional OWSs or SIs. All OWSs were photographed both internally and externally, where possible.

Measurements and configurations of the units were determined through the use of tools and visual observations from the ground surface. No confined space entry took place.

Physical inspection of the facilities and OWSs included a verification of flow, wastewater generating activities, and chemical usage. The inspection also involved visually characterizing the contents and apparent performance of the unit, evaluating the condition and O&M status, and

July 2008 3-2 Final photographing the unit and the surrounding area. In each case, an attempt was made to identify the source of flow to all influent pipes and the destination of flow through all effluent pipes.

When possible, the following physical dimensions were collected and recorded for each OWS:

• Component interior dimensions, including length, width, and height

• Depth to the invert of all influent and effluent pipes

• Locations and dimensions of baffles and skimmers

• Depth to oil, water, and sludge layers

Detailed physical inspections and dimension-gathering was not part of the scope of this study;

however, some dimensions were obtained for many of the units when possible. In order to gather detailed information, the contents of the units would need to be removed and a confined space entry would have to be performed.

3.3 Data Management

URS developed an OWS, Grease Interceptor, and Septic System O&M database as a tool to assist each base with proper management of these systems. The database was created in Microsoft Access™ 2003. The results of the field surveys were entered into the database and the data was evaluated for completeness and accuracy. Cleaning schedules, volumes, locations, shop chemical usage and industrial activities summaries, photographs, maintenance summaries, and additional data is included in the database. No custom queries or reports were programmed for individual bases. The populated database is provided electronically and enclosed with this report.

3.4 Decision Logic and Design Criteria

Inventory results were evaluated to assist in making recommendations regarding the ultimate disposition of each OWS system. To ensure the uniformity of this evaluation process, URS developed a decision logic that incorporates the applicable DoD guidance policies and regulatory requirements applicable to Dyess AFB, as well as commonly accepted technical principles.

The flow chart of the OWS recommendation decision logic is presented as Figure 3-1. Each OWS was evaluated using this decision logic. The actions described below represent the response alternatives derived from this analysis process.

July 2008 3-3 Final

Figure 3-1. OWS Recommendation Decision Flow Chart

July 2008 3-4 Final

• Repair Unit – Recommended for OWSs that were identified as necessary for base operation but are not operating properly or could otherwise be improved by repairs.

A unit that is repaired must also be re-inspected after repair to ensure that the unit is operating properly.

• Eliminate Unit – Recommended when an OWS was determined to be inactive, not required for the current shop activities, not required if sufficient P2 measures were implemented in the shop, or if the flow could be diverted to another nearby OWS.

Elimination can be removal of the OWS or abandonment in place. Removal activity involves cleaning and removal of the OWS, subsoil sampling if contamination is suspected, removal or permanent plugging of influent and effluent lines, covering or plugging any associated floor or trench drains, backfilling the excavation with clean fill material, and restoration of any surface cover. Abandonment activities include cleaning the OWS and rupturing the bottom of the unit. A straight pipe is installed from the influent line to the effluent line, if source(s) of flow will continue, or the influent and effluent lines are permanently plugged. Abandoned OWSs are then backfilled with sand or concrete.

• Remove and Replace Unit – Recommended for required OWSs that are not functioning properly and cannot be repaired. This recommendation involves the cleaning and removal of an old OWS and the installation of a new OWS.

• Install New Unit – Recommended for locations that warrant an OWS or SI but currently have no treatment or inadequate treatment.

To determine if pretreatment was required, each industrial facility surveyed on base was evaluated to identify sources of oily wastewater and potential methods to reduce or limit petroleum, oil, and lubricants (POL) discharge during facility activities. Table 3-1, at the end of this section, presents a list of typical industrial facilities at ACC installations and the recommended pretreatment or oily wastewater elimination practice for each. OWSs deemed necessary for pretreatment were evaluated using a set of design criteria to determine if they were adequately treating the influent stream. A summary of the design criteria used to evaluate existing and recommended OWSs is presented in Table 3-2, at the end of this section.

Tables 3-1 and 3-2 are both based on information in the Draft Final ACC OWS Policy Supplement (2008).

Existing wastewater OWSs were determined to be adequate if the unit design flow rate was greater than the peak influent flow rate that the unit actually receives. The peak influent flow rate was estimated to be the sum of all potential flows from wastewater generating activities that could discharge concurrently to the OWS. For example, the flow rate for a covered wash rack

July 2008 3-5 Final with three bays is equal to the maximum flow rate that would be generated if vehicles were being washed in all three bays simultaneously. The design flow rate for pre-manufactured OWSs was usually listed in manufacturer literature for the particular OWS model and size.

If this information was not available, or if the OWS was cast-in-place, the design flow rate was calculated using Stokes Law, the average oil particle size likely to be introduced into the OWS influent (60 microns is a sufficient estimate for most Air Force applications), and the structural measurements for the main separation chamber. If the peak influent flow rate was estimated to be greater than the unit’s design flow rate, the OWS was deemed inadequately sized and recommended for replacement with an appropriately sized and designed OWS. If the OWS treats flow from a wash rack that is susceptible to storm water flows (e.g., an uncovered outdoor wash rack), an automatic diversion valve system was recommended to be installed. This system would divert storm water to the storm water drainage system when the wash rack is not in use.

All wash water was recommended to be directed to the sanitary or industrial sewer system.

Existing storm water OWSs were deemed adequate if the unit’s design flow rate was greater than the actual influent storm water flow rate. For units that receive captured storm water from secondary containment areas via a valved pipe, the influent flow rate was estimated from the pipe diameter and an assumed minimum pipe slope using Manning’s Equation. For units that receive open storm water flow, from sources such as trench drains and catch basins, the peak flow rate was estimated using the Rational Method. This estimate takes into account the total surface area draining to the OWS, the surface cover of the drainage area, and an assumed rainfall intensity. The 90th percentile rainfall intensity was selected for this analysis to provide an estimation of the flow rate for frequently recurring storm events and the initial portion of large storm events when used in the calculation. The 90th percentile rainfall intensity is the intensity at or below which 90% of all rainfall in a given region occurs. The remaining 10% of rainfall occurs at a higher intensity and would not be treated by an OWS designed using the 90th percentile rainfall intensity. Rainfall intensity distributions vary from region to region. The 90th percentile rainfall intensity distribution can be obtained from Rainfall Intensity Distributions (Allen, 2003) for a limited number of major cities. They may also be obtained for other areas by directly contacting CONTECH (http://www.contech-cpi.com).

A high-level bypass suitable for bypassing storm water flows greater than that predicted by the 90th percentile intensity was recommended for OWSs treating storm water. OWSs determined to be inadequate to treat the 90th percentile storm water flow were recommended for replacement with an appropriately sized and designed OWS, with a high-level bypass to the storm water drainage system. If the influent conveyance device (e.g., trench drain, storm drainage pipe, influent pump) was determined to be inadequate for the storm water flow, it was recommended http://www.contech-cpi.com/

July 2008 3-6 Final that it be upgraded to the appropriate size or capacity to accommodate the 90th percentile storm water flow rate.

New or replacement OWSs are specified to treat the applicable influent flow rate and meet the remaining design criteria listed in Table 3-2. For most applications, an underground, steel, double-walled, enhanced OWS with flow by gravity, cathodic protection, and leak detection is recommended. A separate SI or integral grit chamber (GC) is recommended for activities that contribute significant solids content to the influent stream, such as vehicle washing and storm water applications (see Table 3-1).

Table 3-1. Rationale for OWSs at ACC Facilities

Function or Area Required Minimum

Components Rationale

Maintenance Activities

Aerospace Ground…