Archive for October, 2009
Pacific Water Quality Association Convention – October 2009, Palm Springs CA
I attended the PWQA convention and trade show last week in Palm Springs, CA. I usually don’t visit the PWQA conventions since I see so many of the fine folks at the WQA leadership meetings, but this year I was asked to attend and teach a class to dealers about entering into the commercial and industrial water treatment market.
I stayed in Palm D
esert at the Marriott Shadow Ridge Resort. The resort was great and catered well to a busy business traveller while still affording the amenities and luxuries a one comes to expect from a Marriott resort.
- I tested the water in the villa – 35 grains per gallon of calcium hardness! No softener of course, I hope that one day the fine folks at Marriott will see the wisdom of ion exchange/membrane softening or even Next ScaleStop technology for their hotels and resorts.
While my villa in Palm Desert were great, the Riviera resort in Palm Springs was truly entertaining. The accommodations were comfortable, environment clean and the decor a distinct retro-chic that you just have to experience! The convention itself was very well organized, with Mike Mecca, Frank DeSilva and Kristi Pihl putting in long hours to make it a resounding success. Attendance was better than I expected, with many traveling from California, Nevada, Arizona, Utah and points beyond to learn, buy and sell.
My presentation was about Commercial and industrial Water treatment opportunities for the residential water dealer. This was a hard subject for me to teach because I felt like I was “dumbing-down” the subject matter. I decided to handle it as a “best practices” presentation to allow experienced dealers and novices to glean useful information. We talked about the opportunities, benefits, risks and liabilities of entering this fun market segment. The attendees were particularly interested testing and disinfection protocols like sp-5000 and of course the minutiae of best practices and how to prospect for leads. Great crowd with excellent questions and comments.
Frank DeSilva taught a very interesting class about fluoride and methods for removing it using ion exchange. Frank is an intelligent gentleman who has a great depth of experience and is able to entertain a crowd.
Chubb Michaud made a great presentation about his new design for brine discharge recovery that is tailored to meet the stringent new criteria required by many misinformed local governments who are foolishly maligning softeners. Chubb’s process is a viable alternative that will meet and exceed the latest zero-waste protocols. Even with 9.5 fingers, Chubb is still the master who is head and shoulders above most in the industry.
The trade show itself was also very well attended, with the usual exhibitors and some new ones making their foray into the water treatment industry. In spite of the hard work and beautiful display that we all saw, I do feel that the days of teh traditional “trade show” are numbered, with more and more dealers turning to the internet and other digital media to fulfill their need for information. I predict a continual decline in tradeshow performance and attendance until someone can come up with a good reason to go. Perhaps the associations will place more emphasis on traning and education that is best served in person…
PWQA 2009 – Great fun was had by all.
SchedulePacific Water Quality Association
52nd Annual Convention and Trade Show, October 13 – 16, 2009 Riviera Resort and Spa 1600 N. Indian Canyon Drive, Palm Springs, CA 92262 Convention Schedule
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Controlling Contamination in Water Treatment Equipment—Part 4
Implementing a Disinfection Action Plan
There are several important areas to be addressed in an effective disinfection action plan.
Threat Assessment
Assessing the level of bacterial contamination includes observing odor and appearance of contact surfaces as well as plate culture to determine presence of pathogens.
Physical Cleaning
After the initial assessment, cleaning is the next step and must be thoroughly performed before applying the disinfectant. Experts agree that cleaning alone can remove over 90% of bacteria from surfaces, significantly enhancing the efficacy of the disinfectant compound and minimizing the chances of regrowth/colonization.
This initial cleaning step involves scrubbing, brushing and scraping to physically remove as much gross dirt, biofilm, debris and organic material as possible from all contact surfaces. Cleaning is also important since many disinfectants may be inactivated or ineffective in the presence of organic debris or waste. Disposal of debris into dumpsters should only occur if there is no zoonotic risk of disease transmission. All personnel should wear appropriate protective clothing and footwear. If a zoonotic disease is suspected, enhanced personal protective equipment should be used according to NIOSH protocol.
Surfactant Wash
Washing or sanitizing further reduces the number of microorganisms in the area to a safer level. Educt a anionic or non-ionic surfactant into the treatment equipment, allow sufficient contact time and then rinse vigorously to remove organic and other material. Although cleaning may appear to remove all debris, microscopic biofilm may remain on surfaces and interfere with disinfection efficacy. Biofilm is a complex aggregation of bacteria adhering to surfaces in an exopolysaccharide matrix, resulting in a thin residue that could remain after cleaning. These bacteria are highly resistant to disinfection. Surfactant detergents, mechanical scrubbing, brushing and scraping during cleaning help reduce biofilm. Adding phosphoric acid to the surfactant mixture can be quite efficacious in reducing biofilm accumulation. Multiple bed volumes of fresh water should be rinsed through the system to ensure complete removal of surfactants and contaminants. Some disinfectants can be inactivated by soaps and detergents.
Disinfection
Selection of the proper disinfectant will depend on the microorganism suspected, as well as environmental factors and safety issues. Always read the entire product label and follow dilution instructions explicitly to ensure that the safest, most effective concentration is applied.
To achieve effective disinfection, surfaces must be thoroughly wet and clean; properly mixed disinfectant should be applied at a rate of 0.1 – 0.4L/minute or according to manufacturer’s specifications. Dilution ratios of disinfectant will vary according to type of disinfectant and the specific application. Disinfectant should remain for the appropriate contact time, which will vary with the product and particular application. Equipment should be thoroughly rinsed before returning the system to service.
Evaluation
To verify that all pathogens have been destroyed or reduced to acceptable levels, a follow-up evaluation of the equipment should be conducted. While visual inspection of cleanliness is important, bacteriological samples should be obtained to determine the true effectiveness of the cleaning and disinfection protocol. Failure of a disinfection program usually results from the selection of an ineffective disinfectant, careless use of an effective disinfectant, or environmental factors, such as water hardness, heavy metals, pH, additional contaminants, and water temperature. The timing of sample collection is important. The best time to sample is 2-3 days after disinfection. Surface samples for small, smooth areas, can be collected by wiping or swabbing a sterile swab across a non-porous surface. Commercially available methods include RODAC™ and Petrifilm™ Plates (3M).
These small, flat, sample-ready plates allow on-site microbial testing and are commonly used for food processors. These plates are available for a variety of specific microorganisms or classes (aerobic count plates, coliform count, environmental Listeria etc…) as well as yeast and mold counts and can also be used direct contact or swab applications. Other methods of environmental sampling include surface samples collected by Ultrafilter membrane. Each step of the disinfection action plan (assessment, cleaning, washing/sanitizing, disinfection) should be evaluated for problems encountered and usefulness or efficiency of the cleaning or disinfection techniques.
References and Further Reading
U.S. Environmental Protection Agency. Pesticides: Regulating Pesticides – Registering Pesticides. www.epa.gov/cgi-bin/epaprintonly.cgi
U.S. Environmental Protection Agency. Disinfectants for use on hard surfaces – Efficacy data requirements. www.epa.gov/oppad001/dis_tss_docs/dis-01.htm
U.S. Environmental Protection Agency. Read the Label first
www.epa.gov/pesticides/kids/hometour/label/read
National Institute for Occupational Safety and Health. Comprehensive Procedures for collecting environmental samples for culturing Bacillus anthracis.
http://www.cdc.gov/niosh/unp¬envsamp.html
Antec International Ltd. Emergency disease control: The critical need for modern formulated disinfectants. http://www.antecint.co.uk/main/basichem.htm
Health Canada. Environmental Sampling for the detection of microorganisms.
www.hc-sc.gc.ca/food¬ailment/mh-dm/mhe-dme/compendium/volume_3/e_mflp41
Grow AG. Writing guidelines to require disinfection. Rev. sci. tech. Off. int. Epiz. 1995:14(2);469-477.
http://www.cfsph.iastate.edu
Tamasi G. Testing disinfectants for efficacy. Rev. sci. tech. Off. int. Epiz. 1995:14(1):75-9.
Joklik WK (editor). Ch. 10. Sterilization and disinfection. Zinsser Microbiology. 1992. Appleton and Lange, Connecticut. pp. 188-200.
Kennedy J, Bek J, Griffin D. Selection and use of disinfectants. University of Nebraska Cooperative Extension G00-1410-A. November 2000.
Maris P. Modes of action of disinfectants. Rev. sci. tech. Off. int. Epiz. 1995:14(1):47-55.
Jeffrey DJ. Chemicals used as disinfectants: Active ingredients and enhancing additives. Rev. sci. tech. Off. int. Epiz. 1995:14(1):57-74.
Envirocheck® Rodac plates for surface testing
http://service.merck.de/microbiology/tedisdata/prods/4976¬1_07084_0001.html
3M Petrifilm Plates. Environmental Monitoring Procedures. http://multimedia.mmm.com/mws/mediawebserver.dyn?nnnnnnX7fzBnHRon0RonnnLjxZiqY1Un-