by Paul Higley

Ok, so we all know we should not pour used crankcase oil down the storm drain. Although this is apparently still a problem as the my fair city has found it necessary to place nice ceramic warning sign plaques on all the storm drains reminding us of the hazards of disposing of crankcase oil this way. So what do we do with all the other nasty fluids that make our cherished little cars perform so well? How about brake fluid, transmission fluids, both automatic and manual, power steering fluid and radiator coolant? Well all of these except radiator coolant are petroleum based and eventually go to the same place to be recycled. A district manager at Pep Boys explained that, although they have separate containers for crankcase oil and transmission fluids, they are all pumped into the same container by the recycler. Coolant is water based and the only exception. There are plenty of places to dispose of used oil. But how about used radiator coolant? What are the hazards and where do we dispose of it?

In conversations with some of my favorite “car nuts”, most were properly recycling the used oil. However, I found everyone either pouring used coolant into the old container and throwing it in the trash, dumping it onto the ground or, you guessed it, pouring it down the storm drain. I was surprised that people did this. However, not knowing what to do with it myself and approaching my limit of storage space for the last 20 years of used coolant, I needed to find a better alternative.

I had always heard that ethylene glycol, used in modern radiator antifreeze coolants, was very toxic. In first researching this article it appeared even harder to remove from the water than oil. I assumed it was a major problem for the water treatment centers. Calling on several in the waste water treatment business only seemed to confirm this as none of the treatment centers had techniques in place to remove it from our drinking water.

A search of local repair and parts suppliers was interesting. I found only Pep Boys and my friend Sam at the local Plano German Car repair place would take most fluids. They each had the required collection barrels for used coolant, oil, brake fluid, and transmission fluid. Surely these few are not collecting all the waste fluids we generate. A check at the refuse transfer station for the city found they do collect these for recycling or proper disposal but they do not collect a very large amount. With so few willing to accept used coolant, I decided to center my investigation of car waste fluids on the ethylene glycol.

I thought it would be useful to have a longer chat with those that run the local water treatment facility to get an idea of the magnitude of the problem. First I found that pouring down the storm drain is illegal and subject to a $25,000 fine. But no one could provide answers for how it could be removed before the water left the treatment plant. It appears all that coolant enters our local lakes and rivers only to be again found in our drinking water.

The US EPA has this to say;

“Antifreeze is a substance added to a solvent, such as water, to lower its freezing point. Antifreeze is typically added to water in the cooling system of an internal-combustion engine so that it can be cooled below the freezing point of pure water (32 degrees F) without freezing. Ethylene glycol is the most widely used automotive cooling-system antifreeze, although methanol, ethanol, isopropyl alcohol, and propylene glycol are also used. In automotive windshield-washer fluids, an alcohol (e.g., methanol) is usually added to keep the mixture from freezing; it also acts as a solvent to help clean the glass. Antifreeze is toxic to humans and animals. Waste antifreeze contains heavy metals such as lead, cadmium, and chromium in high enough levels to potentially make it a regulated hazardous waste, so most states strictly regulate antifreeze disposal. Antifreeze generators and state and local programs should not dump spent antifreeze on land or discharge it into a sanitary sewer, storm drain, ditch, dry well, or septic system; dumping antifreeze can cause serious water quality problems and might harm people, pets, or wildlife. “ All well and good but I found the EPA does not issue stated toxic levels for soils and lakes or reservoirs listed the way they do for most other pollutants. A look at state programs revealed little other than “don’t pour it out“ and “dispose of properly”.

The next approach was to try and define the level of toxicity of this Ethylene Glycol. I found government reviews and material toxicity reports stating that kidney, lung, heart and nervous system damage starts at levels as low as 1 or 2 parts per million. Thus the problem appears with only one coolant change being capable of polluting 1 million gallons of water. All this with no way available for treatment plants to remove it. The US EPA lists the maximum that can be spilled down a drain without triggering a pollution problem and this was not all that small an amount. Still a lot smaller than we drain when flushing a car radiator but not milliliters. They regulate the spillage of other hazardous materials to very small traces but they seem unconcerned about ethylene glycol. Actually the EPA states their major concern with automotive waste coolant to be the trace metals which it may contain. Small amounts of chromium, lead and cadmium from corrosion of the metal parts of our engines and not the ethylene glycol itself. Why? It is at least as toxic as many other things they regulate much more stringently. A new report out October, 2007 from the Agency for Toxic Substances and Disease Registry raises the toxic levels to 14 to 20 parts per million. Still not something we should be drinking.

Looking a bit further I found the major source of ethylene glycol entering the environment was airports. It seems that up to 500,000 gallons can be used de-icing planes at a major northern airport and many airports just let it run off into the environment. It dwarfs our efforts to prevent a gallon from entering the local ground water. Still I could not find many articles addressing this as a major problem. Yes, there are efforts in the FAA and airports to recover some of the lost ethylene glycol with Denver perhaps leading the pack with up to 30% recovery of used ethylene glycol. That still means a huge amount is lost. It seemed like a bigger problem than the available literature was addressing. Why is the EPA not declaring all northern airports to be super fund hazard sites?

More articles stated the problem with it entering lakes and rivers being its consumption of oxygen and the resulting fish kills when there is not enough oxygen left in the water for the fish. Ok, but that triggered something to think about. If it absorbs oxygen, can it really be stable in the environment? Well that turns out to be the reason there are not strict limits on spilling it. The ethylene glycol has an average ½ life in soil of a week or two and in water a ½ life of 10 days to two weeks. This does not mean it is gone in a week or two but its concentration decreases by ½ every ½ life period. Some small amount will be there for a lot longer. There is probably a longer residence time around the major airports as the oxygen in the soil is completely consumed by the huge amounts of the run off. So it is toxic, but it does not last long when diluted into soil or water. The ½ life when exposed to open air is also listed as 10 days. It sounds like there is also a good reason to keep the cap on your radiator tight as a loose cap should let in more oxygen and degrade the coolant.

Stop pouring now! You still should not be pouring out your used antifreeze. I do apologize to those that I questioned as hurting the environment. But there is a very good reason not to pour out and dispose of your used coolant. Ethylene glycol is made from natural gas and it takes a lot of natural gas to make a gallon of antifreeze. Natural gas is a finite, non-renewable resource and should not be wasted. We may even need it to power our cars some day. Surely we cannot include that as a “waste”. It also turns out ethylene glycol is a very easy material to recycle and, done properly, the recycled product is just as good as new product. There are even portable recycling machines for sale to smaller garages that can recycle the ethylene glycol for reuse. The only caveat here might be the additives that are needed to prevent corrosion. These additives raise and stabilize pH, inhibit rust and corrosion, reduce water scaling, and slow the breakdown of ethylene glycol. Depletion of these additives is the main reason we flush and replace coolant every 2 or 3 years. The additives are readily available and even at your local AutoZone, O’Reilly’s and Pep Boys and sold as life extenders for your coolant.

This brings us to another subject on coolant. What is the real life span of the coolants available? I have seen 5 year coolant for sale. Does it really work or should we be changing it every 2 years as recommended in most manuals? It turns out that technology is advancing even here. There are now 3 grades, regular with a life of 2 to 3 years, long life with a life of 5 years or 150,000 miles which ever comes first, and extended life with a life up to 600,000 miles. The extended life versions require a booster to the additives that should be added at 300,000 miles. Manufacturers are now expecting that long life antifreeze will be the standard in a very few years. I don’t see the 600,000 mile version of much use to most of our little British cars.

A few closing comments from the American Trucking Association;

DO. . .Keep used antifreeze in a covered container and out of the way of animals, who are often attracted to its sweet flavor. Be sure your recycled antifreeze meets manufacturers' warranties for the vehicle you are servicing. As described above, recycle antifreeze by purchasing or leasing onsite recycling equipment; or using an offsite recycling service. Handle filters and other recycling by-products as hazardous waste.

DO NOT pour antifreeze into sewers, on the ground, or into floor drains, or mix used antifreeze with any other waste. Keep it separate.

DO NOT collect antifreeze in containers that have been used to hold other substances (e.g., gasoline) unless the containers have been thoroughly cleaned. Antifreeze can leach substances from the walls of a container.

Happy Motoring!