A Guidebook for Airport Winter Operations (2015)

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86 This chapter continues the presentation of best practices related to, and in general accordance with the contents of AC 150/5200-30C, Chapter 3, “Snow Clearing Operations and Preventive Measures,” and Chapter 4, “Snow Clearing Operations and Ice Prevention.” Each practice title is followed by a description of the airport type(s) in brackets to which the practice may be most applicable. 10.1 Weather Forecasting Weather Observation and Terminology [All Airports] A basic understanding of the fundamentals of weather observation and weather terminology is of benefit to airport operations personnel. Basic meteorology courses are available at technical schools, colleges, and universities across the country. Many airports train operational personnel as NWS-qualified Certified Weather Observers. In fact, the NWS has recently reached out to airports seeking to bolster the number of certified observers available at airport locations. The training guide for surface weather observations is available via the following link to the NWS website: http://www.weather.gov/om/forms/resources/SFCTraining.pdf. Relationship with Weather Forecast Service Provider [All Airports] Timely and accurate weather forecasts are of vital importance during winter operations. Air- port operators who invest in a full-time, year-round relationship with a specific weather forecast service provider are more likely to receive enhanced weather forecasting services during the winter season. Some airport operators experience the benefit of an on-airport weather service, be it an office of the NWS or a private service provider. Those airports have reported success in schedul- ing regular or seasonal meetings between the respective agencies, including invitations for staff to spend time in the other agency’s work environment. Face-to-face meetings facilitate the opportu- nity for weather service providers to explain their procedures, processes, workload, and time con- straints on a season-by-season basis. Likewise, airport operators have the opportunity to discuss their needs and expectations in an informal, casual setting. In other cases, the physical location of respective offices and operations may not be conducive to face-to-face meetings. However, com- munication technologies are available to address limitations associated with disparate physical locations. Regardless of the methodology, the investment in personal relationships pays dividends during weather events when there is a need for information during periods of heavy workloads. Site-Specific Weather Forecasting [Medium and Large Hub] Weather forecasts prepared by public agencies or by broadcast media outlets historically encompass broad geographical areas. Due to the nature of winter weather events, conditions may vary within that area. Airport operators have become dependent on detailed, site-specific C H A P T E R 1 0 Snow Clearing Operations and Preventive Measures/ Ice Prevention Best Practices

Snow Clearing Operations and Preventive Measures/Ice Prevention Best Practices 87 weather forecasting, albeit at a cost. Contracted services are usually required for site-specific weather forecasting, although there are a limited number of airports that have retained an in-house meteorologist. Operational cost savings may justify salary or contract expenses. Timely and accurate forecasts can lead to reduced costs in the following areas: personnel costs associated with timely and appropriate scheduling of full-time and contracted employees, personnel costs associated with the appropriate number of employees scheduled or called back to the airport commensurate with the level of the snow or ice event, airline delay costs associated with timely snow removal runway closures, and chemical costs associated with the proper application based on atmospheric conditions. A key advantage of most every weather forecasting contract is the ability to conduct on-demand consultation with a weather forecaster. Web-Based Weather Forecasting Tools [All Airports] A significant number of weather forecasting and weather reporting tools are available via the Internet. Airport operators should build a list of web addresses for ready access during a snow or ice event. Each local NWS office maintains a website that provides a wide range of historical, real-time, and predictive weather information. In partnership with the FAA, the National Center for Atmospheric Research provides winter weather forecasting and monitoring tools, which can be researched at: http://www.rap.ucar.edu/projects/deicing/. 10.2 Forecasting Runway Surface Conditions Atmospheric Condition Information [All Airports] Accurate atmospheric condition information and surface condition data are critical compo- nents of the winter operations decision-making process. Most large- and medium-hub airports have installed remote surface and atmospheric condition reporting equipment that transmits real-time data to airfield operations centers or Snow Desks. Data provided include air tempera- ture, sub-surface temperature, surface temperature, freezing point and/or chemical factor, and presence of surface contaminant (moisture, frost, snow, ice). System alarms can be established to warn airport operators of deteriorating or critical conditions. Automated systems such as the Weather Support to Deicing Decision Making System analyze and forecast short-term winter weather conditions in the vicinity of an airport. Multiple data sources enable software algorithms to produce graphical and text depiction of current weather conditions along with one-hour weather forecasts. Data can be archived for future reference. A thorough knowledge of system operation, the ability to interpolate reported metrics, and the proper application of data could lead to significant cost savings with regard to runway closures and chemical applications. Manufacturers provide deicer and anti-icer use and applica- tion criteria often based on surface temperatures and not ambi- ent temperatures. Airport operators should avoid relying on air temperature as an indicator of the effect of atmospheric con- ditions on paved surfaces. During daylight hours, convective heating will raise surface temperatures above the air tempera- ture even when skies are overcast. A bituminous surface will retain more heat and will usually be warmer than adjacent con- crete surfaces. At sunset, surface temperatures will lag behind the decrease in air temperature. It may be well into the eve- ning before the surface temperature equals the relative air tem- perature. Access to surface temperature and surface condition Source: Marcel Boschung AG

88 A Guidebook for Airport Winter Operations information will provide valuable input when determining the proper course of action to address surface conditions. Warm pavements will likely delay the accumulation of light or moderate wet snow. Knowing those conditions, airport operators can limit activities to monitoring surface con- ditions, perhaps even delaying the call-back of personnel to the airport. 10.3 Snow Clearing Principles 10.3.1 LOA Agreement with ATCT for Airport Vehicles Operations on Taxiways [Medium and Large Hub] Agreements between airport operators and the local ATCT allowing airport vehicle opera- tions on taxiways without positive ATC clearances have significantly improved overall airport operations during a snow or ice event. Such a procedure is of particular importance at large- and medium-hub airports. Procedures should be outlined in an appropriate LOA. Factors to con- sider when seeking such an agreement include air traffic controller workload, ground control frequency congestion, airport geometry, availability or operation of ASDE radar, vehicle move- ments, vehicle operator status (full time, part time, or contracted) and vehicle operator training and experience. The level of training required to safely operate a vehicle on the movement area usually limits taxiway access to full-time airport employees. Vehicle operators must be trained that aircraft always have the right of way. Air traffic controllers should be trained to expect flight crews to question the presence or intentions of a snow removal vehicle operating on a taxiway. Air terminal information service message content should include information regarding SRE operating on taxiway surfaces. Communication of Runway Treatment Procedures to ATCT [All Airports] The LOA between the airport and ATC should list standard operational procedures for con- ducting runway snow and ice control operations, including a list of surfaces to be treated during a runway closure. If the full width of a runway is not included in an operation, standard post- closure dimensions should be identified. A listing of connecting taxiways to be treated should also be identified. Procedures should be supported with maps and attachments. Use of Supplemental ATC Frequencies for Communications [General Aviation and Small Hub] Most airports utilize internal company radio frequencies to facilitate communications dur- ing snow or ice control events. Airport operators at smaller facilities have reported success in utilizing a supplemental ATC frequency for snow and ice control communications. The process allows ATC personnel to monitor transmissions, track the movement of snow removal teams, and immediately participate in transmissions to coordinate surface closures. The volume of rou- tine air traffic transmissions should be considered before pursuing the use of an available ATC frequency for snow removal communications, as well as the possibility that such transmissions may distract controllers from their primary tasks. Approval to use an ATC frequency and detailed procedures should be codified in an LOA. 10.3.2 Damage Prevention and Repair Snow Removal Around Edge Lights and Signs [Small, Medium, and Large Hub] Due to the frangibility requirements of edge lights and guidance signs, snow removal from the immediate area around these fixtures is usually accomplished by manual shoveling by a large

Snow Clearing Operations and Preventive Measures/Ice Prevention Best Practices 89 contingent of employees. Equipment specifically designed to remove snow from lights and signs is available on the mar- ket. Equipment cost can be justified by calculating the labor hours saved by implementing mechanical snow removal in lieu of manual snow removal. When investigating potential edge light SRE, consideration should be given to the environment in which the equipment will operate. Whether or not lights and signs are in paved or unpaved areas may dictate the use or type of equipment to be considered. Some equipment operates over the top of the fixtures, while other equipment is offset from the drive vehicle. Although in-pavement lighting is beneficial in maintain- ing capacity during snow events and periods of low visibil- ity, airports should compare the cost-benefit of in-pavement lighting against associated expenses to protect the fixtures. Airports with in-pavement lighting have switched from steel plow blade cutting edges to polyurethane cutting edges. Steel cutting edges are more effective in removing snow but have a higher probability of damag- ing in-pavement light fixtures. In-pavement lights invite snow and compacted snow and ice. Rotary runway brooms are more effective at removing snow from in-pavement lighting fixtures than plow blades. Chemicals may be required to remove compacted snow from in- pavement light fixtures. However, extensive chemical use may damage in-pavement light fix- tures and underground electrical components resulting in additional electrical maintenance requirements and costs. Polyurethane Cutting Edges on Field Plows [Medium and Large Hub] With the increased installation of in-pavement lighting, most airport operators are using polyurethane cutting edges on field plows. Poly cutting edges are, obviously, less damaging to pave- ment and equipment than steel cutting edges. Many airports are specifying caster equipment on plow blades. The casters allow the plow blade to be set slightly above ground level to pro- tect light fixtures and to protect vehicle operators from uneven pavement joints and edges. It has become standard operating procedure to follow a plow with a rotary broom to increase sur- face friction. The design of high-speed, multi-function SRE was based on that premise. Design Considerations for Snow Removal Around Lights and Signs [Medium and Large Hub] The movement of snow removal vehicles around edge lights and guidance signs should be considered in airport design and construction. Paved shoulders will reduce the likelihood of vehicle operations on unpaved areas, thus reducing the prob- ability of ruts and depressions that violate FAR Part 139 safety area standards. Design engineers should consider pavement on both sides of the edge lights. Paved shoulders 35 feet in width have become the standard at most airports that operate large pieces of SRE. That width allows space for vehicle operations on the back side of the edge lights. That design standard is also beneficial in reducing erosion associated with engine jet blast. Source: Fortbrand Services, Inc. Source: Gresham, Smith and Partners

90 A Guidebook for Airport Winter Operations Use of Reflective Tape on Lights and Signs [All Airports] The application of reflective tape to light standards and to the sides of guidance signs will aid SRE operators in identifying the fixtures and will reduce the likelihood of lights and signs being damaged or destroyed. Pre-Event Inspections [All Airports] A thorough pre-event inspection of airfield surfaces to identify foreign object debris contaminant and other hazards may prevent injuries to vehicle operators and may prevent damage to SRE. Electrician Support Vehicle [Large Hub] To immediately address lighting and signage damage, some airports allow electricians to accompany the snow team. Repairs are made during the time interval between the snow removal team passing and the completion of the post-clearing pavement friction measurement. 10.3.3 Snow Clearing Operations Snow Removal Team Lead Vehicle [Medium and Large Hub] The majority of airports employ the use of a vehicle to lead the snow removal team. Usually driven by an airport operations representative or by an airfield maintenance supervisor, the lead vehicle allows maintenance personnel to focus solely on equipment operation. If a lead vehicle is not feasible, at some airports a second person is assigned to the lead plow to handle all coordination and communication with the Snow Desk or with a manager or supervisor. Just-in-Time Runway Treatments [General Aviation and Small Hub] Runway snow removal operations can often be delayed until immediately prior to a known aircraft operation, however, snow removal crews need to account for the accumulation of additional contaminant. Corresponding adjustments to normal snow removal timeframes will likely be required. Just-in-time runway treatments reduce demand on both snow removal operators and SRE. Although the procedure is generally associated with smaller facilities, larger airports may wish to consider just-in-time operations during overnight hours, thereby affording the opportunity to address other areas or to provide additional rest for snow removal personnel. Safety Area Snow Removal During Standard Snow Removal Operations [General Aviation, Small, and Medium Hub] Airports have gained efficiencies by including safety area snow removal in standard snow removal operations as opposed to waiting to conduct safety area operations during post-event or clean-up time periods. If time and adequate snow storage space are not limiting factors, safety margins would be increased by immediately removing snow to distances that exceed AC standards for the most critical aircraft operating at the airport. 10.3.4 Managing Human Factors Provisions for Breaks and Food [All Airports] Airport operators need to pay special attention to human performance factors in preparing for winter operations. A large volume of subject matter material is available for review and reference. Training is available. Airport operators need to provide for basic human needs to support snow removal operations. The provision of food, beverages, and comfortable rest/break facilities has a positive effect on crew morale and crew performance. It is important to keep crews rested and

Snow Clearing Operations and Preventive Measures/Ice Prevention Best Practices 91 alert during extended storms. Crews need to be given routine breaks or be empowered to take breaks as conditions allow. Some airports establish a maximum amount of time an operator can be at the controls of a vehicle. Studies have proven the advantages of short, 10 to 15 minute naps. Crews should be encouraged to take advantage of available breaks and take a quick nap in a vehicle while parked in a safe location. Personnel cannot be expected to maintain continuous operations. The onset of fatigue leads to complacency, errors, and accidents. Personnel should be trained to immediately report to a supervisor or manager when fatigue begins to affect their performance. Advance Scheduling and Overnight Accommodations [All Airports] Manage human performance factors by scheduling employees for snow removal duty as far in advance as possible, by providing food and beverages, and by providing accommodations for rest or sleep. Locker rooms, shower facilities, and kitchen facilities are necessary to sup- port on-airport sleeping quarters. Airports may wish to consider agreements with local hotels to provide staff with sleeping facilities during extended snow events. Sleeping quarters and nearby sleeping arrangements may be of value even when operating rotating shifts. Difficult travel conditions may prevent crew members from returning to the airport for their next shift. Keeping personnel nearby during work breaks ensures maximum crew availability. The availability of onsite or nearby sleeping facilities enhances safety by being able to immediately address crew fatigue. Distractions [All Airports] Vehicle operators need an environment free of distractions in order to more safely operate under stressful and difficult conditions. Most airport operators will follow applicable state laws regarding the use of personal electronic devices (e.g., cell phones, MP3 players) while oper- ating a vehicle. However, due to the dangers inherent with operating a vehicle in the airport environment, most airport operators impose additional restrictions. The use of personal elec- tronic devices while conducting snow removal operations is usually either prohibited or severely restricted. Some airport operators have an “anytime and anywhere” restriction while a vehicle is in motion, while other airports prohibit the devices only while conducting snow removal opera- tions on aircraft movement area surfaces or in aircraft parking areas. Cell phone use is usually permitted in a stationary vehicle. Airport operators can counter an employee claim of the need to be available for family emergency calls by publishing a 24/7 emergency contact telephone number and requiring its use instead of personal cell phones. Multiple radio frequencies can also be a distraction. The majority of airport operators restrict radio use to two frequencies—an internal company frequency and an appropriate ATC ground control frequency. The use of AM/ FM radios is usually prohibited. 10.3.5 Tracking and Reviewing Performance Benchmarking to Industry Peers [All Airports] Although it has proven difficult to identify common numerical benchmark metrics between airports, it is of value to establish and maintain relationships with industry peers in order to be able, at any time, to discuss performance factors and to identify and remedy common problems. Reasons for incompatible metric comparison between airports include unique airport geometry, disparate traffic levels, disparate weather patterns, disparate deployment of staff, different equip- ment fleets, different methodologies, varying internal measurements, and differing manage- ment principles. Airports have found some success in identifying airports of similar size when comparing performance metrics. International airports should not be ruled out when seeking compatible facilities. Runway occupancy time during snow removal operations is one of the few performance metrics tracked by airports. The value in comparing runway occupancy time may

92 A Guidebook for Airport Winter Operations be in determining the type and number of vehicles to be assigned to runway teams, identify- ing the methodology utilized, and establishing the ROI for the number of assets deployed. ROI analysis is critical during discussions with users, specifically air carriers, to determine acceptable costs associated with snow and ice control. Airports noted the importance of benchmarking when seeking solutions to identified prob- lems. The ability to contact an industry peer to seek mitigation options or resolution of a prob- lem is invaluable. Airports specifically identified the importance of attendance and participation at key industry seminars and conferences. Trade shows and conferences present the opportunity to meet and network with industry peers. Personal relationships established at those events facil- itate future communication networks whereby an issue can be discussed with peers at any time. Standard Metrics [All Airports] Consider the use of standard metrics as developed by internationally recognized organiza- tions, such as the International Organization for Standardization, the Society of Automotive Engineers, and the International Facility Management Association. Metrics and measures estab- lished by these organizations are widely recognized by industry professionals. Log of Winter Event Activities [All Airports] Certificated airports are required to maintain a daily log of airport activities. Even with the additional work load created by a snow or ice event, it is of vital importance to maintain a detailed and accurate log of activities during a storm. General aviation airports also benefit from a detailed record of snow removal activities. A storm summary is often attached to the daily log to summarize important data related to the storm, including the amount and type of snow received, snow removal methodology applied, amount of chemicals used, frequency of runway closures, airport capacity, deicing performance, and notable events. An internal storm- to-storm comparison is likely the best benchmarking opportunity available to airport operators. The daily log becomes a short-term and long-term data source for performance review. A daily log becomes a quick reference guide when responding to tenant questions during winter event performance review meetings and can be researched when planning a response to a forecasted snow or ice event. References to decisions and performance during previous events of a similar nature may streamline the planning process for the forthcoming event. Daily log information and event summaries are excellent end-of-season resources for SICC review when considering possible revisions to the SICP. Snow Removal Performance Reviews [All Airports] Many airports conduct snow removal performance reviews at the department or unit level to identify discussion points or procedural matters specific to their area of responsibility. The departmental reviews often lead to internal snow critiques. These forums allow airport opera- tors to identify and mitigate internal issues prior to discussion with the tenants or the SICC at a post-event review. Participation in Regional Snow Removal Conferences [All Airports] Most state governments have departments or agencies that support the development of commercial and general aviation. Those agencies host conferences and workshops throughout the year. Airports are encouraged to be active participants in regional snow removal confer- ences. Networking with regional airports offers airport operators the opportunity to review plans, procedures, and performance with airports that likely experience similar weather con- ditions and share common problems. Participation in regional events is of benefit to smaller airports that may not have the resources or budgetary support to attend national conferences and trade shows.

Snow Clearing Operations and Preventive Measures/Ice Prevention Best Practices 93 10.4 Snow Disposal 10.4.1 Snow Piles Reference Marks for Snow Piles [Medium and Large Hub] Use of reference marks assists in the measurement of snow piles when verifying compliance with AC guidelines. Install pavement markings prior to the winter season to indicate snow pile limits in storage areas. Install frangible markers or snow sticks in safety areas at set distances from pavement edges, run- way centerlines, and taxiway centerlines. These multiple points of reference can be installed to indicate the need for aircraft size restrictions or surface closures. Airports reported the use of a surveyor’s laser to more accurately measure and mark snow piles. Caution is advised when using any laser-based tool. Laser use is usually restricted to overnight hours or at times with no flight operations. Air traffic control should be advised of the use of lasers on the airport. Coordination of Snow Handling Near Aircraft Parking Positions [Medium and Large Hub] Airports that must stockpile snow in or near aircraft parking positions should schedule haul- ing operations at time periods that do not conflict with aircraft movements. Haul routes should be clearly marked and controlled to prevent vehicle deviations along the route. Trucks with large-capacity dump boxes should be considered to maximize per-vehicle loads and to reduce the number of vehicle movements needed to clear an area. Airports that utilize portable snow melting equipment should locate stockpiles in close proximity to storm drains. The movement of loading equipment must also be considered when determining stockpile locations, whether in support of snow hauling or snow melting operations. Snow Compaction [General Aviation and Small Hub] Snow compaction is an alternate method in which to control snow pile heights at the edges of movement area surfaces and in safety areas. “Snow cat” equipment used to groom ski slopes and ski trails can be used to level snow piles. The equipment can also be used to provide a level surface within localizer and glide slope critical areas. 10.4.2 Snowmelters Snow Melting [Large Hub] The use of portable snowmelters eliminates the need to haul snow and reduces potential conflicts between aircraft and the vehicles used in hauling or trucking operations. Snow melting can be accomplished in numerous areas with relatively small footprints. Very few vehicles are required to support melting operations, resulting in reduced fuel use and reduced emissions, even when considering fuel use associated with the melting equipment. Airport and envi- ronmental planners can assist in the development of snow melting site plans, utilizing available drainage systems and Source: Gresham, Smith and Partners Source: Trecan Combustion Limited

94 A Guidebook for Airport Winter Operations other airport infrastructure to support more efficient operations. Many airports print and disseminate graphical snow melting plans for use by contractors, tenants, and other inter- ested parties. Landside Snow Melting [Medium and Large Hub] Snow melting is a viable, cost-effective option for landside snow removal. Portable snow- melters and snowmelters engineered and built into the top levels of parking garages eliminate the stockpiling of snow and the hauling operation that requires the use of height-restricted, low- capacity vehicles. The loss of revenue-generating parking spots is an obvious result of stockpil- ing, and parking structure weight-bearing load factors must also be considered when stockpiling heavy, wet snow. The restricted size of vehicles used for both loading and hauling results in the need for multiple trips between parking garages and snow dump areas. The movement of snow directly to a snow- melter significantly reduces vehicle movements, which increases safety and reduces fuel use and vehicle emissions. Airports that utilize parking garage snowmelters report a rapid return on capital investment and significant cost reduction over time. The use of portable snowmelters at the ground level provides similar benefits. Parking spaces are quickly returned to service and haul- ing costs are eliminated. Not having to consider glycol-impacted snow provides flexibility in the ability to discharge melt water at most storm drains, and the operation is mobile and easily moved from point to point. Airport operators did, however, note the higher frequency of debris being introduced into snowmelters during landside melting operations versus airside. 10.5 Methods for Ice Control and Removal 10.5.1 Chemical Application Effective Chemical Application [All Airports] The proper use and application of pavement anti-icing and deicing chemicals are critical in maintaining a safe airfield environment during winter operations. Airport operators should be trained on proper use and application, and should have a clear understanding of the difference between anti-icing and deicing chemicals. Use parameters, application, and product performance differ. Improper chemical application can result in unnecessary expense and can worsen pavement surface con- ditions. Chemical use training should be included as a required service in contract specifications and/or purchase agreements. The timing and scope of chemical application should be determined by pavement temperature. Pre-treatment of pavement surfaces with anti-icer to prevent frozen contami- nants from bonding to the surface is a conventional preven- tive measure best suited for when pavement temperature is at or below freezing and when high moisture content pre- cipitation is expected. Liquid anti-icer application should be avoided prior to a forecast for dry snow conditions. The pre-application of anti-icer onto surfaces that are above the Source: Trecan Combustion Limited Source: Batts, Inc.

Snow Clearing Operations and Preventive Measures/Ice Prevention Best Practices 95 freezing point should be determined by the presence of sur- face moisture or the forecasted moisture content of frozen precipitation. Pre-application onto pavement surfaces that are above freezing and that have low surface moisture can be operationally beneficial and cost-effective. However, pre- application of liquid anti-icers during or immediately prior to rainfall will likely be ineffective and costly, as the product will quickly dilute and be rendered ineffective. Eventually, frozen precipitation falling onto warm pavement surfaces will melt and create moisture that will dilute applied chemi- cals. Until surface monitoring equipment begins to indicate ineffective chemical concentrations, reapplication onto sur- faces that are maintaining accumulated moisture above the freezing point is unnecessary. Pavement anti-icers should not be used in lieu of deicers. The application of an anti-icer on top of a thick, frozen, con- taminant layer will likely be ineffective. However, deicer application preceding liquid anti-icer application can create a pathway to the pavement surface for the anti-icer, allowing it to break the bond of the frozen contaminant. This may facilitate more efficient break-up and removal of the contaminant. Many pavement deicing chemicals are ineffective when surface temperatures fall below spe- cific thresholds identified by chemical manufacturers. Chemical applications under such condi- tions tend to be excessive with minimum effectiveness and the potential to detrimentally impact stormwater runoff. Maintaining an acute awareness of surface temperatures will result in reduced costs and more efficient operations during snow and ice events. Remote runway surface condi- tion reporting systems may be cost prohibitive for installation at smaller facilities, but a variety of less expensive handheld temperature sensing equipment is also available and can provide the desired temperature data. 10.5.2 Chemical Storage Liquid Pavement Deicer and Anti-Icer Storage Container Spill Containment and Inspection [All Airports] Airport operators and tenants should store liquid pavement deicers and anti-icers in bulk storage containers compatible with the chemical constituents, and in conformance with applicable bulk liquid chemical storage regulations. For bulk storage containers not subject to regulation, secondary con- tainment for the container contents should be provided in a manner that will prevent a leak, spill, or catastrophic failure of the entire container from causing environmental harm by entering nearby stormwater catch basins or surface water bodies. Additionally, airport operators and tenants should develop and implement a bulk storage containers inspec- tion checklist to visually inspect the exterior condition and function of containers, appurtenances, and secondary con- tainment infrastructure on a periodic basis (e.g., monthly). Bulk storage container inspection and integrity testing by a Source: Gresham, Smith and Partners Source: Gresham, Smith and Partners

96 A Guidebook for Airport Winter Operations contracted service provider should also be considered, particularly when secondary contain- ment is not provided. Scheduled professional inspection and integrity testing is especially important for plastic tanks susceptible to ultraviolet degradation when stored outdoors. Location of Liquid Pavement Deicer and Anti-Icer Storage [Medium and Large Hub] Locate liquid pavement deicing and anti-icing chemical storage facilities in a manner to facili- tate landside product delivery. A landside port to airside storage eliminates the need for a security escort during what is often a time-consuming operation. 10.6 Approved Chemicals Next-Generation Pavement Chemicals [Large and Medium Hub] Some pavement chemicals have been found to be incompatible with aircraft braking compo- nents and external electrical wiring systems. Next-generation chemicals are being advertised as having a lesser effect on aircraft components. Airports should coordinate with local air carriers on the cost-benefits of using the more expensive next-generation pavement chemicals. 10.7 Sand Use of Sand on Airside Surfaces [All Airports] Airport operators should consider operational and environmental implications and the costs associated with airside sand applications. Many airports are reassessing sand application fre- quency and application rates. Sand is susceptible to aircraft engine ingestion and damage, despite the use of AC-specified sand gradients. It can also obstruct in-pavement light fixtures and accu- mulate in snowmelter melting pits and stormwater catch basins. In addition to procurement costs, airport operators must also consider ancillary and residual costs: storage building mainte- nance and building environmental controls, liquid anti-icer chemical use as a pre-wetting agent, sand recovery, safety area restoration, and snowmelter and stormwater catch basin maintenance. Several airport operators favor the use of chemicals in lieu of sand. The above-noted costs should be considered when conducting cost-benefit analyses to evaluate sand versus chemical use.