United States Environmental Protection Agency N S » D E f H I S I S S U E Source Water Protection Practices Bulletin Managing Aircraft and Airfield Deicing Operations to Prevent Contamination of Drinking Water AIRPORT PAVEMENT CHEMICAL USE WHY IS IT IMPORTANT TO MANAGE DEICING RUNOFF? AVAILABLE PREVENTION MEASURES ADDITIONAL INFORMATION ANTI-ICING/ DEICING FLUIDS: ADFs are usually 50% ethylene or propylene glycol concentration by volume and have 4 types. Type I ADFs are used for deicing and contain < 1% additives. Types II, III and IV are used for anti-icing, contain up to 2% additives. Type I and IV are used by large airlines for both deicing and anti-icing. Small airlines use Type I or II because anti-icing is not as important. anti-icing operations that take place at airports: the deicing/anti-icing of aircraft, and the deicing/ anti-icing of paved areas including runways, taxiways and gate areas. It also discusses some The Federal Aviation Administration (FAA) requires that aircraft surfaces be deiced and anti-iced to ensure the safety of passengers. However, when performed without prevention measures in place, airport deicing operations can contribute to contamination of ground water and surface water supplies. This bulletin addresses two basic types of deicing/ AIRCRAFT DEICING/ANTI ICING CHEMICAL USE source water contamination prevention measures available for use at smaller airports. Additional information on deicing of roadways is presented in the bulletin on highway deicing. 1Sn owy Airport. The most common technique for deicing/anti- icing of aircraft is the application of chemical deicing/anti-icing fluids (ADF), which are composed primarily of ethylene or propylene glycol. Frequently this is achieved using fixed booms or trucks with an operator bucket mounted on a boom. Temperature and weather conditions dictate the required concentration of glycol in ADF, but most operators use fluid with fifty percent glycol concentration by volume. Deicing/anti- icing fluids also contain additives, including corrosion inhibitors, flame retardants, wetting agents, and thickeners that protect aircraft surfaces and allow ADF to cling to the aircraft, resulting in longer holdover times (the time between application and takeoff during which ice or snow is prevented from adhering to aircraft surfaces). Limited information is available on the actual chemical compositions of ADF because their formulations are considered trade secrets. Four types of deicing/anti- icing fluid are used on aircraft, and vary by composition and holdover time. Type I fluids, which contain glycol and less than one percent additives, are most commonly used for deicing and have relatively short holdover times. Types II, III, and IV fluids are used for anti-icing protection because they contain higher concentrations of additives (two percent or less) in addition to glycol. Larger airlines use both Type I and Type IV fluids for deicing and anti-icing. Because longer holdover times are not as important a consideration at smaller airports, smaller airlines typically use Type I and II fluids, which contain smaller amounts of additives, or no anti-icing fluids at all. ------- Ice and snow is cleared from runways, taxiways, roadways, and gate areas using a combination of mechanical methods (e.g., plows and brushes) and chemical deicing agents. Pavement is pically cleared with mechanical equipment, then chemically treated to prevent further snow and se accumulation. Chemicals commonly used for deicing/ anti-icing include ethylene or propylene glycol, urea, potassium acetate, sodium acetate, sodium formate, calcium magnesium acetate (CMA), or an ethylene glycol- based fluid known as UCAR (containing ethylene glycol, urea, and water). Sand and salt (sodium or potassium chloride) may also be used, 2 ana Mechanical snow removal (left and right) 4 - Chemical snow removal (below) Page 2 Using sand or salt as deicers and anti-icers in airports can cause damage to aircraft surfaces and mechanical parts. WHY IS IT IMPORTANT TO MANAGE SOURCES OF DRI EPA estimates that 21 million gallons of ADF (50 percent glycol concentration) are discharged to surface waters annually from airport deicing operations across the country, and an additional 2 million gallons are discharged to publicly owned treatment works (POTWs). Unless captured for recycling, recovery, or treatment, RUNOFF OF DEICING FLUID NEAR NKING WATER? deicing agents will run off onto bare or vegetated ground where they may travel through the soil and enter ground water, or run off into streams. Unprotected storm water drains that discharge to surface water or directly to the subsurface (i.e., through a dry well) are also of concern. 21 million gallons of ADF are discharged to surface waters annually from airport deicing operations. An additional 2 million gallons are discharged to POTWs. 5 - Surface runoff can reach freshwater storage for drinking water and infiltrate into ground water sources as well. " Precipitation Water Cycle Water storage in ^ Water storage in the atmosphere ice and snow Sublimation Condensation Evapotranspiration Desublimation Fog drip 1 Snowmelt runoff to streams Spring Surface runoff Stfeamflow Evaporation -IW Freshwater, storage Evaporation Water storage in oceans ------- [ AIRCRAFT AND AIRFIELD DEICINS ] Page 3 HEALTH AND ENVIRONMENTAL CONCERNS Ethylene and propylene glycol can have harmful effects on aquatic life due to their high biological oxygen demand (BOD). Depletion of oxygen, fish kills, and undesirable bacterial growth in receiving waters may result. Although pure ethylene and propylene glycols have low aquatic toxicity, ethylene glycol exhibits toxicity in mammals, including humans (with the potential to cause health problems such as neurological, cardiovascular, and gastrointestinal problems, serious birth defects, and even death when ingested in large doses). Additionally, ethylene glycol is considered a hazardous air pollutant (HAP), and is subject to reporting requirements under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). 6 - Fish kill due to low oxygen. Pharynx Larynx Lymph nodes Heart Arteries Musces Bone marrow Ga b adder Stomach Kidneys Skeleton Intestines Veins Pancreas Urinary bladder 7 - Human health effects from glycols, additives and sodium chloride are numerous. 8 - Chlorine corrodes pipes. CHEMICAL EFFECTS Ethylene and propylene glycol have a high biological oxygen demand (BOD), which can result in fish kills and undesirable bacterial growth in aquatic environments. Ethylene glycol is considered a HAP and is subject to CERCLA. Additives in ADFs can be significantly more toxic to aquatic environments than glycols alone. Corrosion inhibitors are highly reactive and produce toxic byproducts. Chloride can corrode pipes and cause problems with coagulation processes in water treatment plants. Additives in deicing/anti- icingfluids can be significantly more toxic to the aqjjaticenvironmentthan glycols alone. Corrosion inhibitors are highly reactive with each other and with glycols; reactions can produce highly toxic byproducts. Other additives such as wetting a gents, flame retardants, pH buffers, and dispersing agents also exhibit high aquatic and mammalian toxicities. Manufacturers and formulators have attempted to reduce the toxicity of additives present in their ADF formula- tions and, when possible, use environmentally benign chemicals. The Society for Automotive Engineers (SAE) is currently working to set an ADF toxicity standard in the near future. Ethylene glycol exhibits toxicity in humans with the potential to cause neurological, cardiovascular and gastrointestinal problems, serious birth defects and even death when ingested in large doses. Sodium chloride, or salt, is applied to paved surfaces to prevent icing. (See the bulletin on highway deicingfor more information on deicing paved surfaces.) Sodium can contribute to cardiovascular, kidney..and-liver diseases, and has a direct link to high blood press u There is no MCL < health advisory level for sodium; however, there is a Drinking Water Equiva- lent Level of 20 mg/L. a non-enforceable guidance level considered protec- tive against non-carcinogenic adverse health effects. Chloride, for which EPA has established a national secondary drinking water standard of 250 mg/L adds a salty taste to water and corrodes pipes. It can also cause problems with coagulation processes in water treatment plants. The water quality standard for chloride is 230 mg/L, basdd on toxicity to aquatic life. ------- [ SOURCE WATER PROTECTION PRACTICES BULLETIN ] AVAILABLE PREVENTION MEASURES TO ADDRESS AIRCRAFT AND AIRFIELD DEICING An overview of several management measures are described in this section, though they are not exhaustive. The reference materials below can provide additional resources and informa- tion. Please keep in mind that individual prevention measures may or may not be adequate to prevent contamination of source waters. Most likely, individual measures should be combined in an overall prevention approach that considers the nature of the potential source of contamination, the purpose, cost, operational, and maintenance requirements of the measures, the vulnerability of the source- water, the public's acceptance of the meas- ures, and the community's desired degree of risk reduction. Page 4 Alternative deicing products have lower toxicities, are readily biodegradable and have a lower BOD in the environment. ALTERNATIVE D E I C I N G / A N T I -1 C I N G MATERIALS Use alternative airfield deicing products such as potassium acetate, sodium acetate, sodium formate, potassium formate, or DMA instead of urea or glycol deicers. These products have lower toxicities, are readily biodegradable, and have a lower BOD in the environment. Many of these products can be applied using the same mechanical spreaders used for urea or spray booms used for glycol-based fluids, (See the bulletin on highway deicing for more information on some of these alternative deicers.) 9 - Infra-red deicing. 10 - Boot deicers are installed on the wings before ice deposition occurs. 11 - Electrical resistive heating mats. REDUCING DEICING/ANTI-ICING FLUID USAGE ON AIRCRAFT: Mechanical deicing technologies eliminate the need for deicing fluids and reduce the need for anti-icing fluid. Below are some examples of this technology: Boot deicing works by inflating a rubber boot located on the leading edge of an aircraft wing. When inflated, the boot causes ice to crack and become dislodged from the surface. Passing air blows the ice away. This method is used primarily on propeller-driven aircraft. Infra-red deicing systems work well for small aircraft, and use natural-gas-fired radiant heaters inside a drive-through hanger. Follow-up chemical deicing or anti- icing is usually required to prevent re-freezing. Electrical resistive heating can remove ice from the surface of small to medium sized aircraft. By applying resistive heating to heating mats located near the skin of an aircraft, ice is melted and is easily dislodged from aircraft surfaces, Hot air blast deicing systems use heated compressed air to blow snow and ice off of aircraft wings. This may be followed by conventional deicing/anti-icing. ------- [ AIRCRAFT AND AIRFIELD DEICINS ] PREVENTION MEASURES Use alternative deicing/anti-icing materials. Reduce the use of deicing/anti-icing fluids: On Aircraft- By using Mechanical deicing: Bootdeicing infra-red deicing Electrical resistive heating Hot air blast Installing a computerized spraying system. Using ice detection sensors. Increasing storage for multi-strength glycol solutions. On Pavement - Promptly using deicing/anti-icing methods. Using mechanical methods for dry snow removal. Using proper amounts of deicing/ anti-icing chemicals. Collect and dispose of spent fluids to reduce runoff by using: Centralized deicing pads Vacuum sweeper trucks Detention basins or constructed wetlands Anaerobic bioremediation systems Transport spent fluid using a sanitary sewer Recycling and recovery of spent fluid. Additional prevention measures: Use of NPDES permits Employee education Monitoring of ground water quality Computerized spraying systems: The installation of a computer- ized spraying system to apply deicing chemicals may reduce the use of deicing/anti-icing flu- ids. These systems can reduce both the volume of deicing fluid used and the time needed for deicing and increase the collec- tion efficiency of runoff. These "carwash" style systems can be operated by personnel with a minimum of training. This option may be cost-prohibitive for Page 5 smaller airports, and in some cases, planes may need addi- tional deicing usingtraditional means (trucks or fixed booms) to deice engine inlets, under- carriages, or the underside of aircraft wings. Deicingfluid sprayed from truck-mounted booms allows more effective and efficient deicing. The de- icer can be sprayed closer to the aircraft surface, reducing over-spray and wastage. Increase storage for mutli-strength glycol solutions Using a technique called "blending to temperature," operators can vary the concentration of glycol in deicing fluid. Operators, particularly at small airports, commonly use a fluid with 50 percent glycol, a concentration that is formulated for worst-case cold weather conditions. However, concentrations of 30 to 70 percent glycol may be used in different con- ditions. Reducing the glycol concen- tration in deicingfluid decreases the amount of glycol in surface runoff and storm water collection systems. ADFs with 50% glycol concentrations are formulated for worst-case cold weather conditions. Reducing the glycol concentration in deicing fluid decreases the amount of glycol in surface runoff. Ice detection systems and sensors: Using ice detection systems or sensors, especially on larger air- craft, can reduce and, in some cases, eliminate application of deicingfluid. Because operators and flight crews often have diffi- culty detecting ice on aircraft wings, aircraft are deiced when- ever ice is suspected to be pre- sent. Magnetostrictive, electro- magnetic, and ultrasonic devices can detect ice on aircraft sur- faces, including areas that are difficult to inspect visually and in cases where ice buildup is not apparent. This allows op- erators to more accurately determine when deicing is unnecessary and can de- crease the amount of ADF used at an airport. ------- R Use mechanical methods for drv snow removal Deicing pads allow for less Type IV anti-icing fluid usage. In addition, fluids recovered from deicing may be suitable for Page 6 12 - Use chemicals as soon as possible to prevent strong bonding of ice to the pavement. 13 - Deicing pad, Ohio, Use mechanical methods for dry snow removal rather than applying chemicals. Use the proper amount of chemicals: Use the proper amount of pavement deicing/anti-icingchemicals by following recommendations from the manufacturer, and properly maintaining spreading equipment. This will reduce unnecessary or over-application of chemicals. Avoid applyingglycol-based deicers near storm drains, particularly those that are not routed to a publicly-owned sewage treatment plant. EDUCING DEICING/ANTI-ICING FLUID USAGE ON PAVEMENT: Promptly use deicing/anti-icing methods: Prevent strong bonding of such as aqueous ice to pavement surfaces by pre-treatingand/or promptly treating pave- ment using either me- chanical methods or chemicals. Pre-treating pavement with chemicals potassium acetate prior to the onset of freezing conditions or a storm event can allow easy removal of snow and ice using sweepers and plows. The FAA esti- \ mates that the correct application of pavement anti-icing chemicals can reduce the overall quantity of pavement deicing/anti- icing agents used by 30 to 75 percent. COLLECTION AND DISPOSAL OF SPENT FLUID TO REDUCE RUNOFF reuse. CENTRALIZED DEICING PADS Centralized deicing pads restrict aircraft deicing to a small area, minimizing the volume and allowing for the capture of deicing waste. A deicing pad is specially graded to cap- ture and route contami- nated runoff to tanks. If the pads are located near gate areas or at the head of runways, deicing may be completed just prior to takeoff; as a result, less Type IV anti-icing fluid may be necessary for shorter holdover times, reducing the amount of glycols re- leased onto the runway or into the air. In addition, fluids recovered from deicing pads may be suitable for reuse. 14 - Vacuum truck, UK. VACUUM SWEEPER TRUCKS: Vacuum sweeper trucks collect spent aircraft and airfield deicingfluids as well as any slush or snow from gate areas, ramps, aircraft parking areas, taxiways, and aircraft holding pads. Vacuum vehicles are a cost- effective alternative to installing traditional drainage collection systems or deicing pads, typically ranging in cost from $200,000 to $400,000 each. In addition, the recovered fluid may be suitable for recycling. I AQIJftfflC 1 1 0845 600 2345J ------- [ B C R A F I AND AIRFIELD D E NG ] NTION BASINS OR CONSTRUCTED WETLANDS storm sewer, Ai too its operating these may be required to install liners to protect ground water and monitoring wells to detect Detention basins or constructed wetlands are open-water ponds that collect ADF runoff from runways and airport grounds. Basins allow solids to settle, and reduce oxygen demand before the runoff is Berm Page 7 Electric Motor with propeller and slinger-ring on vertical motor shaft , Berm discharged to receiving waters. A pump station can discharge metered runoff by way of an airport leakage from breached liners. An aeration system may be required to treat glycol contaminated runoff. (See the storm water bulletin for more information on runoff controls.) Foats 15 - Surface aerated basin. V 16 - Construction of a wetland. ANAEROBIC BIOREMEDIA TION SYSTEM: An economic benefit to the anaerobic remediation process is that it converts glycol in runoff to methane gas that can be used for heating. TRANSPORTATION OF S Transport of spent fluid to a sewage treatment plant by way of a sanitary sewer is almost always the most economical method of treating deicing fluid, provided that sufficient biological loading capacity is available at the treatment plant. However, :orm drains are routed to sanitary sewer. They nould be knowledgeable bout which drains or col- Anaerobic bioremediation systems, in conjunction with sewage treatment plants or detention basins, can be an effective means to dispose of glycol- contaminated runoff, Bioremediation systems generally consist, of a run- off collection and storage system, an anaerobic bioreactor treatment system (one that requires little or no oxygen), and a gas/heat recovery system. These systems can reduce oxygen demand levels sufficiently to permit unrestricted disposal to a sewage treatment plant. Additionally, these systems can remove additives from runoff. An economic benefit to the anaerobic process is that it converts glycol in runoff to methane gas that can be used for heating. PENT FLUID: many sewage treatment plants will only accept limited quantities of glycol-contaminated runoff; check with the appropriate local agency to verify applicable regulations. Airport maintenance crews should not assume that a should about wh lection systems d.~ directly to surface waters or to the subsurface, e.g., through a dry well. fluid to treatment plant ------- [ SOURCE WATER PROTECTION PRACTICES BULLETIN ] RECYCLING AND RECOVERY OF SPENT FLUIDS U & 18 - Recycle Recycling of glycol from spent deicing/anti-icing fluid decreases the amount that reaches and potentially impairs surface and ground waters. The recycling process consists of several steps including filtration, reverse osmosis, and distillation to recover glycol from spent deicingfluid. Technology is available to recycle fluids containing at least 5 percent glycol. Glycol recycling reduces the amount and strength of ADDITIONAL PREVENTION MEASURES Page 8 wastewater, reducing wastewater disposal costs. In addition, the recovered glycol may be sold; the value of recovered glycol depends on the type of glycol and its concentration and purity. Recent developments have made on-site recycling successful at smaller airports; however, the volume of fluid used at very small airports may still be insufficient to make recycling economically viable at these facilities. I ° ° o o ° o I o ° fV oFILToRATEo° o\ . 19 - Filtration 20 - Distillation mrj A + B *[X3 t _L t A + B am Cooling Water ^ Purified A ^ Steam Still Bottoms Under the National Pollutant Discharge Elimination System (NPDES) Permitting Program, airports are required to obtain permit coverage for storm water discharges from vehicle maintenance, equipment cleaning operations, and airport deicing operations. While specific permit con- ditions vary from state-to-state, in general, NPDES storm water permits require airports to develop and implement Storm Water Pollution Prevention Plans (SWPPPs) that include the following elements: NPDES storm water permits require airports to develop and implement SWPPPs. Description of potential pollutant sources and a site map indicating the locations of aircraft and runway deicing/anti-icing operations and identification of any pollutant or pollutant parameter of concern. Description of storm water discharge management controls appropriate for each area of operation. Consideration of alternatives to glycol- and urea- based deicing/anti-icing chemicals to reduce the aggregate amount of deicing chemicals used and/or lessen the environmental impact. Evaluation of whether deicing/anti-icing over-application is occurring and adjustment as necessary. Employee training on topics such as spill response, good housekeeping, and material management practices for all personnel that work in the deicing/anti-icing area. Many NPDES storm water permits issued to airports also require a variety of monitoring activities to evaluate the effectiveness of storm water controls in preventing deicing/anti-icing activities from impact- ing receiving water quality. For example, monitoring requirements for airport deicing/anti-icing activities in EPA's Multi-Sector General Permit include monthly inspections of existing storm water controls during the deicing season (weekly if large quantities of deicing chemicals are being spilled or discharged), quarterly visual monitor- ing of storm water discharges, and periodic effluent monitoringfor BOD, chemical oxygen demand (COD), ammonia, and pH (for larger users of deicing/anti-icing chemicals) during storm events. Storm water that discharges directly to the subsurface by way of dry wells, drain fields, or any other type of distribution system is subject to Underground Injection Control (UIC) Program requirements. These types of drainage systems are regulated as Class V injection wells and operators should contact their state orfederal UIC Program authority for information on applicable regulations. ------- [' AIRCRAFT AND AIRFIELD DEICINQ ] Page 9 EMPLOYEE EDUCATION: Employee training is an important tool in reducing contaminated runoff. Deicing personnel receive eight hours of FAA-mandated training, but industry sources state that three years of experience is required to become adept at aircraft deicing. Personnel should be trained on proper application techniques and best management practices, and be informed of the presence of any sensitive water areas nearby. Properly trained personnel will also use less deicing/antiicing fluid, saving money and reducing contamination Properly trained personnel will use less ADFs, saving money and reducing contamination. Local flow system Direction of flow i \/J Systems Local Intermediate flow system Regional flow system 21 and 22 - Ground water flow and water table map examples from USGS. MONITOR GROUND WATER QUALITY: Monitor ground water quality and identify the direction of ground water movement on-site through the creation of a water table map. Once the direction of ground water flow is known, annual monitoring up gradient and down gradient of deicing areas should provide early detection of deicingfluid contamination and other harmful impacts. 0 13H.47 131.42 o 152.31 O 0 145 03 152.31 o EXPLANATION LOCATION Of WFIL AND altitude of WATEfi TABLE ABOVE SEA LEVEL, IN FEET o 126 78 13221 O 0 137 90 140 WATER TABLE CONTOUK- Shows altitude of water tabte. Contour interval 1( feet. Datum is sea level: 121.34 O Q 128.31 GROUND-WATER FLOW LINE Q\ 136 <7 , 15231 >5/ ° 131 4? ? O 145.03 \ o \ 126.fU 132.21 O 137.90 121.34 0 " - . 0 128,37 130.47 1314? O O 145.00 132.21 O Q 1ZB./8 1 i ¦ ¦ i l.'l 34 12637 ADDITIONAL INFORMATION These sources contain information on airport deicing practices and facilities and provide prevention measures to avoid source water contamination. All of the documents listed are available for free on the Internet. Bremer, Karl. The Double Deicing Dilemma. Airport Magazine. http://www.airportnet.org/depts/publicat/airmags/am91093/deicing.htm Bremer, Karl. The Three Rs, Reduce, Recover and Recycle. Airport Magazine. http://www.airportnet.org/depts/publiea1/AIRMAG3/Am3498/deiGfng.htffi FAA(2001) Northwest Mountain Regional Airport Plan 2001. http://www.nw.faa.gov/airports/Plans/RAP/ FAA (2001) Electronic Aircraft Icing Handbook. Chapter III http://www.fire.tc.faa.gov/aar421/eaihbpg.html FAA Management of Airport Industrial Waste. Change 1 (1997) and Change 2 (2000) http://www.faa.gov/arp/pdf/5320-151.pdf http://www.faa .gov/a rp/pdf/5300-142. pdf ------- ^ SOURCE WATER PROTECTION PRACTICES BULLETIN Page 10 Minnesota Pollution Control Agency. (2000) Protecting Water Quality in Urban Areas: Best Management Practices for Dealing with Storm Water Runoff from Urban, Suburban and Developing Areas of Minnesota. http://vwvw.pca.state.mn.us/water/pubs/swm-ch7.pdf Switzenbaum, Michael S., Shawn Veltman, Theodore Schoenberg Carmen Durand, Dean Mericas, and Bryan Wagoner. (1999) Best Management Practices for Airport DeicingStormwater. University of Massachusetts Water Resources Research Center. http://www.umass.edu/tei/wrrc/pdf/Switzl73.pdf USEPA. (1999) Storm Water Technology Fact Sheet: Airplane Deicing Fluid Recovery Systems. EPA-832-F-99-043, United States Environmental Protection Agency Office of Water, Washington DC. http://www.epa.gov/owm/mtb/airplnde.pdf USEPA. (1998) EPA Office of Compliance Sector Notebook Project: Air Transportation Industry, Sector Notebook Project, EPA/310-R-97-001. http://es.epa.g0v/0eca/sect0r/#air USEPA. (2000) Preliminary Data Summary: Airport Deicing Operations (Revised). EPA-821- R-00-016, United States Environmental Protection Agency Office of Water, Washington, DC. http://www.epa.gov/ost/guide/airport/airport.pdf USEPA. (2001) Contaminant Candidate List Preliminary Regulatory Determination Support Document for Sodium, EPA 815-R- 01-014, United States Environmental Protection Agency, Office of Water. http://www.epa.gov/safewater/ccl/pdf/sodium_final_rsd.pdf USEPA. (No Date) EPA Office of Federal Activities: Pollution Prevention / Environmental Impact Reduction Checklist for Airports. http://es.epa.gov/oeca/ofa/pollprev/airport.html USEPA. (No Date) Shallow Injection Wells (Class V). Available at http://www.epa.gov/safewater/uic/classv.html IMAGE CREDITS 1 - Flickr Creative Commons: Attribution only search. Waiting Time, uploaded by "DieselDemon" on February 2, 2009. http://www.flickr.eom/photos/28096801@N05/3248216549/ 2 - Flickr Creative Commons: Attribution only search. The snow clearer's dance, uploaded by "James_Cridland" on March 10, 2008. http://www.flickr.com/photos/jamescridland/2325743696/ 3 - Flickr Creative Commons: Attribution only search. Not Actually Winterpeg!, uploaded by "WireLizard" on December 14, 2008. http://www.flickr.com/photos/wirelizard/3108973513/ 4 - Flickr Creative Commons: Attribution only search. Sea-Tac Airport Snow Removal Practice, uploaded by "Michael @ NW Lens" on Novemeber4, 2009. http://www.flickr.com/photos/aboyandhisbike/4076255704/ 5 - United States Geologic Survey: The Water Cycle - Water Science for Schools, http://ga.water.usgs.gov/edu/watercycle.html 6 - Flickr Creative Commons: Attribution only search. 24/365 Fish Kill., uploaded by "BLW Photography" on October 4, 2009. http://www.flickr.com/photos/macbeck/3982210565/ 7 - Wikimedia Commons Public Domain Image: Internal Organs. http://commons.wikimedia.Org/wiki/File:lnternal_organs.png 8 - Flickr Creative Commons: Attribution only search. Pipe @ Avila Beach, California, uploaded by "timparkinson" on December 2, 2006. http://www.flickr.com/photos/timparkinson/312604512/ 9 - Radiant Energy Corporation: Radiant Aviation. Accessed July 23, 2010. http://www.radiantenergycorp.com/product.htm ------- AIRCRAFT AND AIRFIELD DEICING Page 11 10 - PilotFrierid.com: Flight Safety - icing conditions in flight, http://www.pilotfriend.com/safe/safety/Icing_conditions.htm 11- Sloan, Jeff, High-Performance Composites: "787 integrates new composite wingdeicingsystem". January 2( Gardner Publications, http://www.compositesworld.com/articles/787-integrates-new-composite-wing-deicing-system / 12 - Flickr Creative Commons: Attribution only search. Time, uploaded by "alancleave/_2000" on July 12, 2008. http://www.flickr.com/photos/alancleaver/2661425133/ 13 - RW Armstrong Projects: Cleveland Hopkins Airport - Deicing, completed in 2006 http://www.rwa rmstrong.com/project.aspx?id =494 14 - Flickr Creative Commons: Attribution only search. After the UK runs out of grit aVtd salt for the roads the Highland Council comes up with an innovative solution to clearing snow!, uploaded by "foxypar4" on February 14, 2009. http://www.flickr.com/photos/foxypar4/3278603278/ 15-Wikipedia Public Domain Image: Surface-Aerated Basin. http://en.wikipedia.Org/wiki/File:Surface-Aerated_Basin.png 16-Wikipedia Public Domain Image: Newly planted constructed wetland. http://en.wikipedia.org/wiki/Constructed_wetland 17 - Flickr Creative Commons: Attribution only search, roads and railways series #1, uploaded by "woodleywonderwork" on October 14, 2008. http://www.flickr.com/photos/wwworks/2942952271/ 18 - Recycling logo. 19 - Wikipedia. Attribution/Share-Alike license: FilterDiagram, uploaded by "Wikiwayman" on August 4, 2009. http://en.wikipedia.Org/wiki/File:FilterDiagram.svg 20 - Wikipedia Free Art License: BatchDistill. http://en.wikipedia.0rg/wiki/File:BatchDistill.svg 21 and 22 - United States Geologic Survey. T.C. Winter, J.W. Harvey, O.L. Franke, and W.M. Alley. "Ground Water and Surface Water A Single Resource." Denver, Colorado, 1998. Accessed July 26, 2010. http://pubs.usgs.gov/circ/circll39/ 23 - O'Liner, Mark. CENews.com, "Cold-weather Contaminants: Airports begin planning for federal guidelines regulating management of glycol deicing fluids." April 2007. http://www.cenews.com/magazine-article-cenews.com-april-2007-cold_weather_contaminants-4998.html Back Cover - University Corporation for Atmospheric Research: Communications Archives - UCAR Quarterly: Winter/Spring 1997. Anatta, "Deicing forecasts unclog LaGuardia and 0'Ha re Airports." http://Avvw.ucar.edu/communications/quart.erly/spring97/deicing.html 3 - Airplane deicing. ------- SOURCE WATER PROTECTION PRACTICES BULLETIN MANAGING AIRCRAFT AND AIRFIELD DEICING OPERATIONS TO PREVENT CONTAMINATION OF DRINKING WATER The mission of EPA is to protect human health and to safeguard the natural environment - air, water and land - upon which life depends. USEPA East (EPA East) [Old ICC Building] 1201 Constitution Avenue N.W. Washington, DC 20004 United States Environmental Protection Agency Office of Water (4606) EPA ### ### ### ### www. epa.go v/safewater August 2010 ------- |