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Fuel and oil spills, salts and chlorides used on runways, glycols used to deice planes, as well as solvents and grease are some of the things we can find in the waterways
around the airport. The airport does have a waste water discharge permit issued by the state DNR. Would you be surprised to learn that the airport can't come even close to meeting the necessary requirements? Read on!
WATER POLLUTION FROM GMIA CAUSES CONCERN THROUGHOUT THE COMMUNITY
GMIA is having trouble keeping toxic deicing fluids and other contaminants out of our waterways. ANA, along with others, have asked for a
public hearing on the reissuance of a wastewater permit by DNR. DNR Public Notice (PDF)
Airports' Waste Water Discharge Permit issued by the Wisconsin DNR.
The DNR has subsequently reissued the permit to GMIA
despite the fact that the airport cannot properly recover de-icing contaminates. What a mockery of our environmental laws! If you wish to comment contact us at
airportneighbors@earthlink.net
OR
Cheryl Nenn -- Riverkeeper/Project Director
Friends of Milwaukee's Rivers
1845 N. Farwell Ave., Suite 100
Milwaukee, WI 53202
414.287.0207x29 / 414.273.7293(F)
Email: cheryl_nenn@mkeriverkeeper.org
Web site: www.mkeriverkeeper.org
Here's our opinion Re: GMIA WPDES (Wisconsin Pollutant Discharge Elimination System) Permit to Discharge
Facts from the Public Notice: The estimated amount of
fugitive glycol that can't be captured because it adheres to aircraft, dissipates as vapor, is used outside the management area, or otherwise can't be collected, was increased from 50% to 60%. This resulted in a
reduction in the glycol capture goal from 42.5% to 34%. If the glycol collection goal isn't attained, the airport must make additional efforts to comply. The airport is falling short of the goal, but continues to make
improvements (most improvements are to the terminal, runways, and parking structures, not environmental improvements).
[The monitoring program collects water quality data, but there are no numerical water quality based effluent limitations because they currently don't apply to storm water
discharges. This technicality needs to be changed; or the airport's storm water system needs to reclassified as an industrial discharge system. I believe the airport is zoned as heavy industrial, so why
shouldn't its wastewater discharges be considered the result of that industry and be regulated accordingly?]
Facts from the Permit Application: Goal is to
capture 85% of glycol. If the percent captured for disposal or recycling meets or exceeds the annual glycol capture goal percentage, the airport shall be considered in compliance. [34% is recovered (see above) meaning
less than ½ the goal has been achieved, which makes the airport noncompliant]
Conclusion: The airport continues to be clearly noncompliant in regard to wastewater discharges, yet the DNR has tentatively
decided that the permit should be reissued, probably based on a technicality. I'd like someone from DNR or Milwaukee County government to tell me this is OK. I'd like to hear the rationalization for zapping the life out
of our waterways – especially when a less expensive, less polluting alternative is available.
What I think we have here in Milwaukee is an airport administration that apparently believes such things as artist
designed terrazzo floors and "Blue Shirt" artwork on hugh parking structures are more important than the surrounding environment. You would think the cash strapped airlines would be screaming for an infrared
deicing system since it costs about 75% less than fluid deicing.
Jim Baker, Secretary, ANA |
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Toxicity of Deicing/Anti-Icing Agents
During aircraft and airfield deicing operations, deicing agents are released to the land, air, and surface waters. Release of these agents adversely affects the
environment, aquatic wildlife, and human health.
Aircraft deicing/anti-icing fluids (ADFs) typically contain water, glycols, and additives. Emphasis added.
The toxicity exhibited by ADFs is due in
part to the presence of glycols (which typically make up approximately 45% to 65% of the total fluid by weight when applied), but is also due to the additives contained in the fluids. Although additives comprise a small
percentage of ADFs (e.g., less than 2%), they may be responsible for a disproportionate share of the toxicity of ADFs.
Several toxicity studies have been performed using pure ethylene glycol and
propylene glycol but few studies have been performed using formulated ADFs. The formulations are considered trade secrets, and only limited information is currently available on the actual chemical compositions of
formulated ADFs. Some
information is available on the types of compounds that may be included as additives in ADFs. The fluid manufacturers indicate that their formulas change often, potentially as often as every
year. In general, toxicity studies are available for pavement deicers either from literature sources or from the manufacturers.
Toxicity of Additives and Formulated ADF
ADFs typically
consist of a formulation of ethylene glycol or propylene glycol, water, and chemical additives such as flame retardants and corrosion inhibitors. The additives contribute significantly to the overall toxicity of ADFs.
For example, available data demonstrate that the additives in ADFs may cause adverse aquatic toxic effects. For these reasons, it is important to examine the toxicity of formulated fluids in addition to that of pure
propylene glycol to determine the toxicological effects of ADFs released to the environment from the Airport deicing/anti-icing operations. The identity of the actual chemicals used as additives is not known because the
ADF manufacturers claim this information confidential; however, general information is known about the types of additives and their possible role in the toxicity of ADFs.
Based on available data, the
toxicity exhibited by pure propylene glycol is significantly lower, and therefore less toxic, than the corresponding formulated fluids. The reason for this difference is the toxicity of the chemicals that are added,
albeit in small amounts, to formulated fluids.
Test results indicate that formulated fluids are more toxic than pure glycol substances. For example, in a study conducted at Stapleton Airport in Denver,
Colorado, a propylene glycol-based ADF exhibited significantly more acute aquatic toxicity than pure propylene glycol. In chronic studies performed at the airport, the concentration that inhibits growth and reproduction
in 25% of the test organisms (IC) of pure propylene glycol for fathead was 6,941 mg/L, whereas the IC of propylene glycol-based deicing ADF (type unknown) was 112 mg/L.
Aircraft Deicing Fluid Components
The identity of many of the chemical compounds that are added to deicing fluids is unknown for proprietary or "trade secret" reasons; however, general information about the types of additives that
may be included in fluid packages is known. For example, typical ADF components include or have included:
1. Ethylene glycol or propylene glycol;
2. Water;
3. Surfactants (wetting agents);
4. Corrosion inhibitors (including flame retardants);
5. pH buffers;
6. Dyes;
7. 1,4-Dioxane; and
8. Complex polymers (thickening agents in Type II and Type IV ADFs).
Other common additives (or
manufacturing byproducts) include diethylene glycol, ethylene oxide, and acetaldehyde.
Deicing fluids are composed mostly of glycol and water. The remaining components comprise about 1% or less of Type I
fluids and 2% or less of Type II and Type IV fluids. ADFs are required to meet performance-based standards that are established by the Society for Automotive Engineers (SAE).
SAE standards for deicing
fluids can be found in Aerospace Material Specification (AMS) 1424, and for anti-icing fluids in AMS 1428. ADFs would be unable to meet SAE standards without additives. The potential adverse environmental and health
effects of each of the ADF components are discussed below. Glycol
Fluid formulations contain varying amounts of glycol. Typical Type I ADFs contain approximately 90% glycol (by weight) in concentrated form.
As applied, they contain between 30% and 60% glycol (typically approximately 50%), whereas Type II and Type IV ADFs contain higher percentages of glycol, closer to 65 percent.
In general, by themselves,
both ethylene glycol and propylene glycol are relatively nontoxic to the aquatic environment. Glycols, both ethylene and propylene are both biodegradable, but in order to do so, they exert a high biochemical oxygen
demand on the receiving stream (as measured by BOD [biochemical oxygen demand], CBOD sub5 [carbonaceous biochemical oxygen demand], and COD [chemical oxygen demand]).
BOD is the measure of the amount of
dissolved oxygen needed to break down (or oxidize) a substance. A high BOD means that large amounts of dissolved oxygen in water must be used up to oxidize the substance, thereby reducing the amount of dissolved oxygen
available for fish and other aquatic organisms to breathe. For this reason, fish kills have been associated with discharges of deicing chemicals. Other environment impacts associated with deicing chemicals include
odors, foam and contaminated surface water and groundwater. Deicing solutions used at Airports also contain additives including anti-corrosive agents and surfactants. Many of these additives, or their breakdown
products, are toxic to humans and wildlife and otherwise harmful to the environment.
Upon information and belief, at least several of these additives are hazardous substances within the meaning of
CERCLA and EPCRA. Deicing solution, including propylene glycol, may be discharged to the environment in harmful amounts if not
properly controlled. Because deicing solutions pose serious health and environmental
risks, various environmental laws control their use.
Surfactants
Surfactants, or wetting agents, are substances that reduce the surface tension of fluids and aid fluids in spreading or
adhering to aircraft surfaces. They may comprise approximately 0.4% to 0.5% by volume of deicing fluids. Surfactants can be very toxic to aquatic organisms. At acutely toxic concentrations (concentration unknown), the
primary effect on fish would be damage to gill tissue.
i
Corrosion Inhibitors and Flame Retardants
Corrosion inhibitors act to prevent aircraft components that have been covered with
deicing/anti-icing fluids from corroding, and flame retardants act to reduce the flammability hazard created when fluids are applied to metal aircraft surfaces that carry electric currents.
Corrosion
inhibitors may comprise up to 0.5% by volume of ADFs and are present at approximately 100 to 300 mg/L. The corrosion inhibitor and flame retardant most commonly used in deicing fluids is 5-methyl-1H-benzotriazole
(common name: tolyltriazole or TTZ), although 1H-benzotriazole (common name: benzotriazole or BTZ) may also be used. Aquatic toxicity data available for TTZ indicate that it is significantly more toxic than glycols.
Another common corrosion inhibitor includes phosphate esters, which may comprise up to 0.125% by volume of deicing fluids.. Phosphate esters ((RO) PO) are derivatives formed by phosphoric acids and alkyl or
aryl alcohols. The degree of toxicity of phosphate esters varies. Some phosphate esters can be highly toxic and even carcinogenic. Other common corrosion inhibitors include sodium nitrite, sodium benzoate, and borax.
Corrosion inhibitors are highly reactive with each other and with glycols, which can result in high biological toxicity. In general, corrosion inhibitors are considered toxic chemicals because of their high
reactivity potential.
pH Buffers
pH buffers are solutions that maintain the fluid at a constant pH. The addition of alkali or acid would result in only minimal changes to fluid pH. pH
buffers are thought to comprise less than 0.25% by volume of deicing fluids. A common pH buffer is potassium hydroxide, which on its own is highly caustic upon contact, may be lethal upon ingestion, and is extremely
corrosive. Colorants or Dyes
Colorants or dyes (organic based) are chemicals used to color deicing fluids. They are thought to comprise less than 0.25% by volume of deicing fluids. Deicing fluids are
colored to make them visible so that deicing personnel can see where fluids have been applied and where they have fallen to the ground. In general, Type I fluids are dyed orange and Type II and IV fluids are dyed green.
Due to the wide range of potential colorants used in ADFs, no useful information could be collected on the toxicity of colorants or dyes.
1,4-Dioxane
1,4-Dioxane is used as a
wetting and dispersing agent and is thought to comprise less than 0.5 mg/L of deicing fluids. Dioxane is a suspected carcinogen and/or teratogen. EPA has reason to believe that some fluid manufacturers have removed
1,4-dioxane from their formulations.
1,4-dioxane has low acute aquatic and mammalian toxicity and may be irritating to humans on contact; however, it can exhibit significant chronic toxicity. Prolonged
exposure to 1,4-dioxane has resulted in several human deaths.
Diethylene glycol
Diethylene glycol is an eye and human skin irritant. Exposure to diethylene glycol may result in nausea,
vomiting, headaches, unconsciousness, convulsions, and even death. It can also cause degenerative changes in the kidneys and liver, respiratory failure, cardiovascular collapse, acute renal failure, and brain damage,
renal failure, hepatitis, pancreatitis, central nervous system impairment, coma, and death.
Toxicity of Pavement Deicers
Pavement deicing agents cause significant adverse environmental
impacts. Pavement and runway deicing and anti-icing agents approved by the FAA include potassium acetate, calcium magnesium acetate (CMA), sodium acetate, and sodium formate. Corrosion inhibitors are often added to
runway deicers to meet the SAE and MIL-SPEC specifications. As discussed in above, corrosion inhibitors may exhibit high mammalian and aquatic toxicity. Each of the approved agents and resulting adverse aquatic and
health effects is discussed below. These agents also create adverse biochemical oxygen demand when released into waters.
Potassium Acetate and Sodium Formate
Potassium acetate also places a
significant oxygen demand (BOD) on receiving waters. The Airport has not demonstrated that it treats Potassium Acetate and Sodium Formate laden stormwater prior to its discharge.
Based on
EPA-sponsored site visits, potassium acetate is currently the most commonly used runway and pavement deicer on airports throughout the United States. Potassium acetate alone is corrosive, so it is mixed with corrosion
inhibitors, and is slightly flammable. The identity and toxicity of corrosion inhibitors typically added to potassium acetate runway deicers is not currently known.
Sodium formate is typically applied in
a pellet form and is mixed with corrosion inhibitors to meet the required specifications. Significant exposure to sodium formate deicer may adversely affect people suffering from chronic disease of the respiratory
system, skin, and/or eyes.
Sodium Hydroxide - Runway de-rubberizer
The Airport has not demonstrated that it treats its sodium hydroxide laden stormwater prior to its discharge into receiving
waters. DNR should consider runway de-rubberizer as a "prohibited non-stormwater discharge." EPA prohibits the discharge of aircraft ground vehicle, runway and equipment washwaters; and dry weather discharges of deicing
chemicals. These discharges must be covered by a separate WPDES permit.
Fuel Storage/Leakage
Fuel leakages are caused by human error and poorly maintained equipment. As most of this spillage
occurs outside of hangers, it is almost certain that if a proper cleanup operation is not performed then the fuel will be washed into the surrounding soil and watercourses. Fuel has a high BOD, is toxic to plants and
animals, and when it occurs on the surface of water can inhibit aeration of the
water.
Aircraft Maintenance
Chemicals including solvents, paints, oil, grease, cleaning fluids etc are all
routinely used during maintenance of aircraft. Although the use of these chemicals is strictly controlled, spillages can occur and toxins can be washed into watercourses. Degreasing solvents in particular are highly
toxic.
Vehicle washings contain heavy metals, detergents, solids, oils and grease and solvent residues. These substances vary in their toxicity but all have a high BOD and COD. Detergents contain high
levels of phosphates which can lead to eutrophication.
Firefighting Pollutants
Firefighting foams are regularly used during live fire drills and are liable to migrate into surrounding soil
or watercourses.
General stormwater discharge.
In addition to the pollutants associated with specific airport activities, the creation of large expanses of impervious surface at the airport
results in pollutant loading and hydrologic change that contribute to the present violations in the receiving waters. These pollutants likely include, but are not limited to, fertilizers (phosphorus and nitrogen),
pesticides, herbicides, organic solvents and phenols, toxic metals, sand and other solids, salt, fuels, detergents, oil and grease; as well as other pollutants that cause violations of water quality standards for COD,
BOD, TSS, and pH. Furthermore, creation of large expanses of impervious surfaces causes substantial modification of the hydrologic regime of the airport site. The increased runoff from impervious and less pervious areas
contributes to disruption of the natural characteristics of the receiving waters and impairs habitat. |
