A check on check valves
As usual, I have enjoyed reading one of John Beauchamp’s articles in this month’s WC&P (“Groundwater: Custom Plumbing for Wells—A Valve for Every Occasion,” December 1999, pp. 50-53). Despite many years of water treatment experience, I always find his features informative and excellent review material.
However, I have two problems with this paper. First, a minor omission is the importance of proper expansion equipment on hot water heating equipment. He mentions adding check valves after water softeners to prevent hot water backup and pressure regulating devices. Both of these require the use of properly operating expansion tanks on the hot water heating system.
The second observation concerns the use of a check valve at the pressure tank tee. I believe the only proper place for a check valve in a well system would be at the submersible pump and every 100 feet of drop pipe (or at the foot valve with a jet pump). We service many home well systems every year that have problems with the service pipe into the home. With ground settling and other causes, many service pipes are kinked and damaged at the pitless adapter or as the line passes through the house foundation. With a check valve at the pressure tank, this is normally not noticed until the leak is so severe that the pump never shuts off. Without a check valve, the leak normally shows itself, or the pump running on and off is noticed sooner. Most important, the line stays pressurized so that contaminant water cannot leak back into the water supply line.
Thanks for the great articles. Keep up the good work!
Dave Judy, CWS-V, CI
Water System Services
Author responds: Both of the points he makes are valid. I don’t really have any additional comments, except to say that where I live, almost all wells have check valves at the pressure tank on the pump side and this certainly represents common practice here. —John Beauchamp
C14: Down but not out
I would like to bring to your attention an inaccuracy found in the International Focus news brief “Canadian certification import bill dropped,” (WC&P, December 1999) dealing with Canada’s Drinking Water Materials Safety Act, formerly Bill C-14.
For your information, acts introduced before the Canadian Parliament must follow the legislative process, as was the case for Bill C-14. This act was introduced during the previous session of parliament and was at its second reading when the session was prorogued. At that time, Bill C-14 and all other bills not adopted by both chambers of parliament died on the order paper. In other words, Bill C-14 had not been refused a second reading by the House of Commons as indicated in the news item, but rather had not completed the process.
Bill C-14—and all other bills that died on the order paper—can be reintroduced during the next session of parliament. Any decision to reintroduce a bill must be made by the government.
Véronique Morisset, coordinator
Drinking Water Materials Safety Act
Product Safety Bureau/Health Canada
Not necessarily a hot topic
I read the article by Larry Grubb (Grubb, Larry, “Niche Markets: From Agriculture to Industry—Tablet Chlorination Serves Disinfection Needs,” WC&P, December 1999) with great interest. I was quite surprised to see that the author continually made reference to the “safest aspect” of utilizing tablet chlorination. PPG Industries Inc. (his employer) distributes a videotape titled “safety is the key” that specifically addresses how violently this form of chlorine reacts with many commonly found materials. Oils, grease, fertilizers, moisture and even Coca-Cola can cause rapidly spontaneous combustion and the release of chlorine gas. Because this product is so readily available, it is perceived to be safe. It is in fact the only form of chlorine that is both flammable and combustible.
Chlorine gas, the form of chlorine Mr. Grubb suggests users avoid because of safety concerns, is statistically the safest form of chlorine available today. Chlorine gas is 100 percent available chlorine, with no additives, and is hypochlorite. Chlorine gas is currently the most effective and economical form of chlorine to use in water treatment. All forms of chlorine need to be treated with respect. It is quite possible that chlorine gas’ classification as a hazardous chemical is due to its widespread use. Increased usage of alternate forms will most likely result in increased regulation.
Author responds: I need to point out that calcium hypochlorite (cal-hypo) is neither flammable nor combustible; but when contaminated—such as with oils or greases—it will give off oxygen that can promote combustion of other materials.
In fact, all oxidizers, including cal-hypo and chlorine gas, react violently with oils, greases, etc., and each requires proper handling. Minimal safe handling procedures such as storage in the original, closed container in a cool, dry location will prevent contamination.
Finally, we have received feedback from numerous customers that they feel much safer handling cal-hypo than gas.