Regarding Mr. Ing’s and Mr. Warnes’ rebuttal of the article Multibarrier Microbiological Filtration (W&CP, Feb. 2006), there are a number of points that they fail to address, and their rebuttal is confusing in some areas. Allow me to attempt to clear up some outstanding issues.

I stand by my claim that no POE system has passed NSF P-231. NSF’s listings show there is only one system that can make such a claim: a multibarrier POU purifier. Mr. Ing and Mr. Warnes can log onto the Internet and go to NSF’s Web site to see for themselves.

Regarding Mr. Ing’s and Mr. Warnes’ claims that their product has been tested for “claimed actual capacity,” I challenge them to provide test data that proves their system was challenged with microbiological contaminants either periodically or continuously for the full 130,000 gallons claimed (and beyond, since there is no requirement to change the membranes in their system each year). They should also reread my article so they can see that I indicated the claimed annual capacity of their POE system was “more than 100,000 gallons,” not an absolute 100,000 gallons as they claim I stated.

Regarding water waste, Mr. Ing and Mr. Warnes should check their math. The 3,900 gallons their system wastes per year (three percent of 130,000 gallons) is more than twice the potential 1,500 gallons used by a typical POU multibarrier purifier device to produce drinking and cooking water during the same time frame. This points to the validity of using POU equipment to produce high purity water so the process is not wasteful, which is what happens when you send such high quality water to toilets, dishwashers, washing machines, etc.

Mr. Ing and Mr. Warnes also claim there’s no way to verify actual POU system performance and that it’s a benefit to go through extra steps and take extra time at the installer’s expense to use their integrity tester to verify their system is operating properly. If they were familiar with our company’s manufacturing process, they would know that the microbiological barriers are tested several times during production to verify performance so that it’s not necessary for the dealer to do it at his expense and to eliminate potential problems at installation. Also, as the article clearly points out, the medical-grade membranes employed are used in critical, high-purity applications where failure is not an option. They were specifically selected for this reason.

Another point that Mr. Ing and Mr. Warnes tried to claim in their rush to throw stones at multibarrier POU systems was that they need frequent cartridge changes, which is untrue. In fact, our system only requires service to replace the prefilter and postfilter approximately once per year and the microbiological barrier filters only once every four years! Even the RO membrane the system uses as one of its protective stages carries a full (not pro-rated) seven-year warranty! Mr. Ing’s and Mr. Warnes’ POE system requires service once per year and on some water supplies, more often than that!

Mr. Ing and Mr. Warnes also tout their system’s ability to function on municipal, well, surface or rainwater supplies as an advantage. If they wanted to be completely truthful, they would have pointed out that the multibarrier POU purifier can also function on the same types of water and during boil alerts, water main breaks, cross contamination and other events that could potentially introduce pathogens into consumers’ drinking water.

I also disagree with Mr. Ing’s and Mr. Warnes’ characterization that a manufacturer would include several barriers to achieve what their system can in a single barrier. It’s not that the system requires it, but that the manufacturer feels that public health is too important an issue to gamble on with a system that has no safeguards in the event of a failure.

While I believe there is a need for POE purification, I stand behind my statement that additional work needs to be completed on Mr. Ing’s and Mr. Warnes’ product to ensure protection against a possible system breakdown. It isn’t just a matter of passing a one-time test; a microbiological purifier must consistently and reliably perform over its entire expected lifetime.

Additionally, Mr. Ing and Mr. Warnes neglected to address other issues I raised in the article. Reread the article and you’ll notice Mr. Ing and Mr. Warnes shied away from addressing the topics of real-life field testing on known, contaminated water supplies, cartridge incubation and microbiological grow-through testing, conservative volume claims using only a percentage of the actual life testing in order to build in a safety factor and how their customers are supposed to know if their system is not working properly after their installer has left with his handheld integrity tester.

Mr. Ing and Mr. Warnes also fail to address the inability of their system to remove the wide range of non-microbial contaminants that a POU multibarrier purifier can handle. Other concerns include what happens if microbes are introduced into the plumbing system downstream of their POE product (which points to the need for POU purification as close to the dispensing device as possible) and their misleading claim that their system requires no electricity to filter the water (few processes do, of course). Does the system require a plug or not?

Despite the differences in opinions on this topic, the debate is healthy for our industry and the companies involved. By continuing to push the technology envelope, we will be positioned to deliver better products that ultimately offer additional protection to our customers.


David W. Krupinski, CWS-VI
Manager – Residential Markets
Kinetico Incorporated
10845 Kinsman Road, Newbury, OH 44065


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