RAATS: RCRA Administrate Action Tracking System

RAC: Radiation Advisory Committee. Raw Agricultural Commodity; Regional Asbestos Coordinator. Response Action Coordinator

RACM: Reasonably Available Control Measures

RACT: Reasonably Available Control Technology

RAD: Radiation Adsorbed Dose (unit of measurement of radiation absorbed by humans)

RADM: Random Walk Advection and Dispersion Model; Regional Acid Deposition Model

RAM: Urban Air Quality Model for Point and Area Source in EPA UNAMAP Series

RAMP: Rural Abandoned Mine Program

RAMS: Regional Air Monitoring System

RAP: Radon Action Program; Registration Assessment Panel; Remedial Accomplishment Plan; Response Action Plan

RAPS: Regional Air Pollution Study

RARG: Regulatory Analysis Review Group

RAS: Routine Analytical Service

RAT: Relative Accuracy Test

RB: Request for Bid

RBAC: Re-use Business Assistance Center

RBC: Red Blood Cell

RC: Responsibility Center

RCC: Radiation Coordinating Council

RCDO: Regional Case Development Officer

RCO: Regional Compliance Officer

RCP: Research Centers Program

RCRA: Resource Conservation and Recovery Act

RCRIS: Resource Conservation and Recovery Information System

RD/RA: Remedial Design/ Remedial Action

R&D: Research and Development

RD&D: Research, Development and Demonstration

RDF: Refuse-Derived Fuel

RDNA: Recombinant DNA

RDU: Regional Decision Units

RDV: Reference Dose Values

RE: Reasonable Efforts; Reportable Event

REAP: Regional Enforcement Activities Plan

REE: Rare Earth Elements

REEP: Review of Environmental Effects of Pollutants

RECLAIM: Regional Clean Air Initiatives Marker

RED: Reregistration Eligibility Decision Document

REDA: Recycling Economic Development Advocate

ReFIT: Reinvention for Innovative Technologies

REI: Restricted Entry Interval

REM: (Roentgen Equivalent Man)

REM/FIT: Remedial/Field Investigation Team

REMS: RCRA Enforcement Management System

REP: Reasonable Efforts Program

REPS: Regional Emissions Projection System

RESOLVE: Center for Environmental Conflict Resolution

RF: Response Factor

RFA: Regulatory Flexibility Act

RFB: Request for Bid

RfC: Reference Concentration

RFD: Reference Dose Values

RFI: Remedial Field Investigation

RFP: Reasonable Further Programs. Request for Proposal

RHRS: Revised Hazard Ranking System

RI: Reconnaissance Inspection

RI: Remedial Investigation

RIA: Regulatory Impact Analysis; Regulatory Impact Assessment

RIC: Radon Information Center

RICC: Retirement Information and Counseling Center

RICO: Racketeer Influenced and Corrupt Organizations Act

RI/FS: Remedial Investigation/ Feasibility Study

RIM: Regulatory Interpretation Memorandum

RIN: Regulatory Identifier Number

RIP: RCRA Implementation Plan

RISC: Regulatory Information Service Center

RJE: Remote Job Entry

RLL: Rapid and Large Leakage (Rate)

RMCL: Recommended Maximum Contaminant Level (this phrase being discontinued in favor of MCLG)

RMDHS: Regional Model Data Handling System

RMIS: Resources Management Information System

RMP: Risk Management Plan

RNA: Ribonucleic Acid

ROADCHEM: Roadway Version that Includes Chemical Reactions of BI, NO₂, and O₃

ROADWAY: A Model to Predict Pollutant Concentrations Near a Roadway

ROC: Record Of Communication

RODS: Records Of Decision System

ROG: Reactive Organic Gases

ROLLBACK: A Proportional Reduction Model

ROM: Regional Oxidant Model

ROMCOE: Rocky Mountain Center on Environment

ROP: Rate of Progress; Regional Oversight Policy

ROPA: Record Of Procurement Action

ROSA: Regional Ozone Study Area

RP: Radon Progeny Integrated Sampling. Respirable Particulates. Responsible Party

RPAR: Rebuttable Presumption Against Registration

RPM: Reactive Plume Model. Remedial Project Manager

RQ: Reportable Quantities

RRC: Regional Response Center

RRT: Regional Response Team; Requisite Remedial Technology

RS: Registration Standard

RSCC: Regional Sample Control Center

RSD: Risk-Specific Dose

RSE: Removal Site Evaluation

RTCM: Reasonable Transportation Control Measure

RTDF: Remediation Technologies Development Forum

RTDM: Rough Terrain Diffusion Model

RTECS: Registry of Toxic Effects of Chemical Substances

RTM: Regional Transport Model

RTP: Research Triangle Park

RUP: Restricted Use Pesticide

RVP: Reid Vapor Pressure

RWC: Residential Wood Combustion

S&A: Sampling and Analysis. Surveillance and Analysis

SAB: Science Advisory Board

SAC: Suspended and Cancelled Pesticides

SAEWG: Standing Air Emissions Work Group

SAIC: Special-Agents-In-Charge

SAIP: Systems Acquisition and Implementation Program

SAMI: Southern Appalachian Mountains Initiative

SAMWG: Standing Air Monitoring Work Group

SANE: Sulfur and Nitrogen Emissions

SANSS: Structure and Nomenclature Search System

SAP: Scientific Advisory Panel

SAR: Start Action Request. Structural Activity Relationship (of a qualitative assessment)

SARA: Superfund Amendments and Reauthorization Act of 1986

SAROAD: Storage and Retrieval Of Aerometric Data

SAS: Special Analytical Service. Statistical Analysis System

SASS: Source Assessment Sampling System

SAV: Submerged Aquatic Vegetation

SBC: Single Breath Cannister

SC: Sierra Club

SCAP: Superfund Consolidated Accomplishments Plan

SCBA: Self-Contained Breathing Apparatus

SCC: Source Classification Code

SCD/SWDC: Soil or Soil and Water Conservation District

SCFM: Standard Cubic Feet Per Minute

SCLDF: Sierra Club Legal Defense Fund

SCR: Selective Catalytic Reduction

SCRAM: State Consolidated RCRA Authorization Manual

SCRC: Superfund Community Relations Coordinator

SCS: Supplementary Control Strategy/System

SCSA: Soil Conservation Society of America

SCSP: Storm and Combined Sewer Program

SCW: Supercritical Water Oxidation

SDC: Systems Decision Plan

SDWA: Safe Drinking Water Act

SDWIS: Safe Drinking Water Information System

SBS: Sick Building Syndrome

SEA: State Enforcement Agreement

SEA: State/EPA Agreement

SEAM: Surface, Environment, and Mining

SEAS: Strategic Environmental Assessment System

SEDS: State Energy Data System

SEGIP: State Environmental Goals and Improvement Project

SEIA: Socioeconomic Impact Analysis

SEM: Standard Error of the Means

SEP: Standard Evaluation Procedures

SEP: Supplementary Environmental Project

SEPWC: Senate Environment and Public Works Committee

SERC: State Emergency Planning Commission

SES: Secondary Emissions Standard

SETAC: Society for Environmental Toxicology and Chemistry

SETS: Site Enforcement Tracking System

SF: Standard Form. Superfund

SFA: Spectral Flame Analyzers

SFDS: Sanitary Facility Data System

SFFAS: Superfund Financial Assessment System

SFIP: Sector Facility Indexing Project

SFIREG: State FIFRA Issues Research and Evaluation Group

SFS: State Funding Study

SHORTZ: Short Term Terrain Model

SHWL: Seasonal High Water Level

SI: International System of Units. Site Inspection. Surveillance Index. Spark Ignition

SIC: Standard Industrial Classification

SICEA: Steel Industry Compliance Extension Act

SIMS: Secondary Ion-Mass Spectrometry

SIP: State Implementation Plan

SITE: Superfund Innovative Technology Evaluation

SLAMS: State/Local Air Monitoring Station

SLN: Special Local Need

SLSM: Simple Line Source Model

SMART: Simple Maintenance of ARTS

SMCL: Secondary Maximum Contaminant Level

SMCRA: Surface Mining Control and Reclamation Act

SME: Subject Matter Expert

SMO: Sample Management Office

SMOA: Superfund Memorandum of Agreement

SMP: State Management Plan

SMR: Standardized Mortality Ratio

SMSA: Standard Metropolitan Statistical Area

SNA: System Network Architecture

SNAAQS: Secondary National Ambient Air Quality Standards

SNAP: Significant New Alternatives Project; Significant Noncompliance Action Program

SNARL: Suggested No Adverse Response Level

SNC: Significant Noncompliers

SNUR: Significant New Use Rule

SO²: Sulfur Dioxide

SOC: Synthetic Organic Chemicals

SOCMI: Synthetic Organic Chemicals Manufacturing Industry

SOFC: Solid Oxide Fuel Cell

SOTDAT: Source Test Data

SOW: Scope Of Work

SPAR: Status of Permit Application Report

SPCC: Spill Prevention, Containment, and Countermeasure

SPE: Secondary Particulate Emissions

SPF: Structured Programming Facility

SPI: Strategic Planning Initiative

SPLMD: Soil-pore Liquid Monitoring Device

SPMS: Strategic Planning and Management System; Special Purpose Monitoring Stations

SPOC: Single Point Of Contact

SPS: State Permit System

SPSS: Statistical Package for the Social Sciences

SPUR: Software Package for Unique Reports

SQBE: Small Quantity Burner Exemption

SQG: Small Quantity Generator

SR: Special Review

SRAP: Superfund Remedial Accomplishment Plan

SRC: Solvent-Refined Coal

SRF: State Revolving Fund

SRM: Standard Reference Method

SRP: Special Review Procedure

SRR: Second Round Review. Submission Review Record

SRTS: Service Request Tracking System

SS: Settleable Solids. Superfund Surcharge. Suspended Solids

SSA: Sole Source Aquifer

SSAC: Soil Site Assimilated Capacity

SSC: State Superfund Contracts

SSD: Standards Support Document

SSEIS: Standard Support and Environmental Impact Statement;. Stationary Source Emissions and Inventory System.

SSI: Size Selective Inlet

SSMS: Spark Source Mass Spectrometry

SSO: Sanitary Sewer Overflow; Source Selection Official

SSRP: Source Reduction Review Project

SSTS: Section Seven Tracking System

SSURO: Stop Sale, Use and Removal Order

STALAPCO: State and Local Air-Pollution Control Officials

STAPPA: State and Territorial Air Pollution

STAR: Stability Wind Rose. State Acid Rain Projects

STARS: Strategic Targeted Activities for Results System

STEL: Short Term Exposure Limit

STEM: Scanning Transmission-Electron Microscope

STN: Scientific and Technical Information Network

STORET: Storage and Retrieval of Water-Related Data

STP: Sewage Treatment Plant. Standard Temperature and Pressure

STTF: Small Town Task Force (EPA)

SUP: Standard Unit of Processing

SURE: Sulfate Regional Experiment Program

SV: Sampling Visit; Significant Violater

SW: Slow Wave

SWAP: Source Water Assessment Program

SWARF: Waste from Metal Grinding Process

SWC: Settlement With Conditions

SWDA: Solid Waste Disposal Act

SWIE: Southern Waste Information Exchange

SWMU: Solid Waste Management Unit

SWPA: Source Water Protection Area

SWQPPP: Source Water Quality Protection Partnership Petitions

SWTR: Surface Water Treatment Rule

SYSOP: Systems Operator

TAD: Technical Assistance Document

TAG: Technical Assistance Grant

TALMS: Tunable Atomic Line Molecular Spectroscopy

TAMS: Toxic Air Monitoring System

TAMTAC: Toxic Air Monitoring System Advisory Committee

TAP: Technical Assistance Program

TAPDS: Toxic Air Pollutant Data System

TAS: Tolerance Assessment System

TBT: Tributyltin

TC: Target Concentration. Technical Center. Toxicity Characteristics. Toxic Concentration:

TCDD: Dioxin (Tetrachlorodibenzo-p-dioxin)

TCDF: Tetrachlorodi-benzofurans

TCE: Trichloroethylene

TCF: Total Chlorine Free

TCLP: Total Concentrate Leachate Procedure. Toxicity Characteristic Leachate Procedure

TCM: Transportation Control Measure

TCP: Transportation Control Plan; Trichloropropane;

TCRI: Toxic Chemical Release Inventory

TD: Toxic Dose

TDS: Total Dissolved Solids

TEAM: Total Exposure Assessment Model

TEC: Technical Evaluation Committee

TED: Turtle Excluder Devices

TEG: Tetraethylene Glycol

TEGD: Technical Enforcement Guidance Document

TEL: Tetraethyl Lead

TEM: Texas Episodic Model

TEP: Typical End-use Product. Technical Evaluation Panel

TERA: TSCA Environmental Release Application

TES: Technical Enforcement Support

TEXIN: Texas Intersection Air Quality Model

TGO: Total Gross Output

TGAI: Technical Grade of the Active Ingredient

TGP: Technical Grade Product

THC: Total Hydrocarbons

THM: Trihalomethane

TI: Temporary Intermittent

TI: Therapeutic Index

TIBL: Thermal Internal Boundary Layer

TIC: Technical Information Coordinator. Tentatively Identified Compounds

TIM: Technical Information Manager

TIP: Technical Information Package

TIP: Transportation Improvement Program

TIS: Tolerance Index System

TISE: Take It Somewhere Else

TITC: Toxic Substance Control Act Interagency Testing Committee

TLV: Threshold Limit Value

TLV-C: TLV-Ceiling

TLV-STEL: TLV-Short Term Exposure Limit

TLV-TWA: TLV-Time Weighted Average

TMDL: Total Maximum Daily Limit; Total Maximum Daily Load

TMRC: Theoretical Maximum Residue Contribution

TNCWS: Transient Non-Community Water System

TNT: Trinitrotoluene

TO: Task Order

TOA: Trace Organic Analysis

TOC: Total Organic Carbon/ Compound

TOX: Tetradichloroxylene

TP: Technical Product; Total Particulates

TPC: Testing Priorities Committee

TPI: Technical Proposal Instructions

TPQ: Threshold Planning Quantity

TPSIS: Transportation Planning Support Information System

TPTH: Triphenyltinhydroxide

TPY: Tons Per Year

TQM: Total Quality Management

T-R: Transformer-Rectifier

TRC: Technical Review Committee

TRD: Technical Review Document

TRI: Toxic Release Inventory

TRIP: Toxic Release Inventory Program

TRIS: Toxic Chemical Release Inventory System

TRLN: Triangle Research Library Network

TRO: Temporary Restraining Order

TSA: Technical Systems Audit

TSCA: Toxic Substances Control Act

TSCATS: TSCA Test Submissions Database

TSCC: Toxic Substances Coordinating Committee

TSD: Technical Support Document

TSDF: Treatment, Storage, and Disposal Facility

TSDG: Toxic Substances Dialogue Group

TSI: Thermal System Insulation

TSM: Transportation System Management

TSO: Time Sharing Option

TSP: Total Suspended Particulates

TSS: Total Suspended (non-filterable) Solids

TTFA: Target Transformation Factor Analysis

TTHM: Total Trihalomethane

TTN: Technology Transfer Network

TTO: Total Toxic Organics

TTY: Teletypewriter

TVA: Tennessee Valley Authority

TVOC: Total Volatile Organic Compounds

TWA: Time Weighted Average

TWS: Transient Water System

TZ: Treatment Zone

UAC: User Advisory Committee

UAM: Urban Airshed Model

UAO: Unilateral Administrative Order

UAPSP: Utility Acid Precipitation Study Program

UAQI: Uniform Air Quality Index

UARG: Utility Air Regulatory Group

UCC: Ultra Clean Coal

UCCI: Urea-Formaldehyde Foam Insulation

UCL: Upper Control Limit

UDMH: Unsymmetrical Dimethyl Hydrazine

UEL: Upper Explosive Limit

UF: Uncertainty Factor

UFL: Upper Flammability Limit

ug/m3: Micrograms Per Cubic Meter

UIC: Underground Injection Control

ULEV: Ultra Low Emission Vehicles

UMTRCA: Uranium Mill Tailings Radiation Control Act

UNAMAP: Users' Network for Applied Modeling of Air Pollution

UNECE: United Nations Economic Commission for Europe

UNEP: United Nations Environment Program

USC: Unified Soil Classification

USDA: United States Department of Agriculture

USDW: Underground Sources of Drinking Water

USFS: United States Forest Service

UST: Underground Storage Tank

UTM: Universal Transverse Mercator

UTP: Urban Transportation Planning

UV: Ultraviolet

UVA, UVB, UVC: Ultraviolet Radiation Bands

UZM: Unsaturated Zone Monitoring

VALLEY: Meteorological Model to Calculate Concentrations on Elevated Terrain

VCM: Vinyl Chloride Monomer

VCP: Voluntary Cleanup Program

VE: Visual Emissions

VEO: Visible Emission Observation

VHS: Vertical and Horizontal Spread Model

VHT: Vehicle-Hours of Travel

VISTTA: Visibility Impairment from Sulfur Transformation and Transport in the Atmosphere

VKT: Vehicle Kilometers Traveled

VMT: Vehicle Miles Traveled

VOC: Volatile Organic Compounds

VOS: Vehicle Operating Survey

VOST: Volatile Organic Sampling Train

VP: Vapor Pressure

VSD: Virtually Safe Dose

VSI: Visual Site Inspection

VSS: Volatile Suspended Solids

WA: Work Assignment

WADTF: Western Atmospheric Deposition Task Force

WAP: Waste Analysis Plan

WAVE: Water Alliances for Environmental Efficiency

WB: Wet Bulb

WCED: World Commission on Environment and Development

WDROP: Distribution Register of Organic Pollutants in Water

WENDB: Water Enforcement National Data Base

WERL: Water Engineering Research Laboratory

WET: Whole Effluent Toxicity test

WHO: World Health Organization

WHP: Wellhead Protection Program

WHPA: Wellhead Protection Area

WHWT: Water and Hazardous Waste Team

WICEM: World Industry Conference on Environmental Management

WL: Warning Letter; Working Level (radon measurement)

WLA/TMDL: Wasteload Allocation/Total Maximum Daily Load

WLM: Working Level Months

WMO: World Meteorological Organization

WP: Wettable Powder

WPCF: Water Pollution Control Federation

WQS: Water Quality Standard

WRC: Water Resources Council

WRDA: Water Resources Development Act

WRI: World Resources Institute

WS: Work Status

WSF: Water Soluble Fraction

WSRA: Wild and Scenic Rivers Act

WSTB: Water Sciences and Technology Board

WSTP: Wastewater Sewage Treatment Plant

WWEMA: Waste and Wastewater Equipment Manufacturers Association

WWF: World Wildlife Fund

WWTP: Wastewater Treatment Plant

WWTU: Wastewater Treatment Unit

ZEV: Zero Emissions Vehicle

ZHE: Zero Headspace Extractor

ZOI: Zone Of Incorporation

ZRL: Zero Risk Level