We need to double back to a column topic from earlier this year and make some important clarifications regarding our advice on the use of methanol as an anti-freeze additive. Our research at the time of the article came mostly from our friends in the Flagstaff, Ariz., area, which is certainly not the best example of a “freezing” area.
Therein lies the rub. Informative responses to that story came from Bob Herman of Herman Plumbing Co. in Grand Island, Neb., and others, who deal with temperatures well below zero. In fact, we’re sure that some PROs work in temperatures that can reach -20 to -30 degrees and need proper advice for pumping in those severe conditions.
First off, we’d like to thank Herman for making us aware that certain concentrations of methanol and water are flammable.
As Herman notes, “We have used a methanol and brine solution combination in our fleet to keep the toilets thawed out, along with softener salt (pellets) in the urinal to keep urinal usage from diluting the brine/methanol mix in the holding tank.” He added that there usually wasn’t much done for washdown during the winter other than using windshield washer fluid; the PROs in frigid climates hope that users are tidy and in-the-field cleanup isn’t a major issue.
“In some cases we have even had to pick up one with a frozen holding tank or dirty floor and switched it out with a clean one and brought the frozen one back to the shop to thaw out and clean,” Herman says.
Another excellent point is made by Ross Odom, a PRO in Arkansas. As Odom states, “It is against the law to put methanol or anti-freeze or anything remotely associated with these products (methanol and/or anti-freeze) in the portable toilet waste stream. That is to say, treatment plants will not allow these products to be disposed of into their systems.” Odom adds that even small amounts of these chemicals are banned.
Then again, using rock salt is not a great answer either. As Odom states, “The solution has to be near perfect or it will freeze if there is not enough salt or if there is too much salt in the solution.”
Anytime there are foreign chemicals used in the mix, waste treatment plants are suspicious and generally will say no to dumping at their site. Waste disposal is watched more closely now than ever before at treatment plants, especially for carbon-based products. So even chemicals like magnesium chloride become suspect. The downside of magnesium chloride is that it is expensive, and like the other solutions, must be perfectly mixed to suit the weather or it will not work properly. If you are dumping at a treatment plant, it’s critical to find out what they accept and what they don’t.
Odom adds, “I am not aware of any anti-freeze products that are allowed in treatment facilities aside from salt-based products, and our treatment facility is trying to outlaw those products.” Many of the treatment plants use bacteria to digest waste and, Odom says, “anything that the ‘bugs’ don’t like is out!”
These are great points brought out by readers. Every area deals with portable restroom waste in different ways. The bigger cities have treatment plants and they want to know what you are dumping and they will test each load to verify. Some are more restrictive than others. Know, understand and abide by the rules and regulations in your area.
As desert dwellers, both Jerry and I have learned a lot from this lesson. As Ross Odom states, “The best possible solution to the overall problem is heaters in-line that keep the liquids liquid.”
This doesn’t solve the problem of the frozen portable restroom, but somewhere out there is an inventor who is going to be very well off when he or she comes up with the environmentally safe anti-freeze product and/or mechanical device. Let’s face it. Once the temperature dips below 32 degrees, the process changes. Contractors in every region deal with freezing in unique ways.
