Six-year hunt for ways to disinfect water WHEN IT announced its pref- erence of chlorine over chlo- ramine as a secondary disin- fectant for the Lower Mainland's drinking water, the Greater Vancouver Regional District (GVRD) put an end to a search that began six years ayo. By Greg Felton Contributing Writer In 1988, the GVRD began a demonstration-scale testing pro- gram to find the best secondary dis- infectant us part of its Drinking Water Quality Improvement Plan, begun in 1985. Though there are many methods of purifying water, the choice came down to either chlorine or chlo- ramine. Secondary disinfection is dis- tinct from primary disinfection, which takes place before the water enters the distribution system. Secondary disinfection prevents bacterial regrowth in the water sys- tem; primary disinfection kills bac- teria and other waterborne contami- nants before the water gets into the distribution system. If the source wate! is clean enough and the water system is small enough then 2 primary disin- fectant like chiorine will also serve as a secondary disinfectant. However, if the source water is not clean enough or the system is SECONDARY Wednesday, June 15, 1994 - North Shore News - 3 ary solution IZ errr WATER DISINFECTANTS REJECTED BY THE GREATER VANCOUVER REGIONAL DISTRICT (GVRD) IN A Chlorine dioxide). Ditinfectant quality: i; viruses and Poor byproducts, too large, a secondary disinfection may be necessary. B.C. is currently the only province without a full secondary water disinfection system. Some parts of the Lower Mainland water system do contain residual disinfectant, therefore sec- ondary disinfection is required. Chloramine was rejected as a secondary disinfectant principally because of its deleterious effect on marine and aquatic organisms, said Doug Neden, GVRD manager of No more chemicals needed, say groups From page 1 toward ozone, filtration and biofil- tration.” Harris said that people are now prepared to pay more in household water bills for fewer chemicals in their water. The GVRD board will cast a final vote on the water committee's recommendation at the board's June 29 meeting. The exact number of rechlorina- tion booster stations, where they will be distributed throughout the region and who's going to pay — the province or the municipality ~— has yet to be finalized. But about 3ix stations are pro- posed for North Vancouver District compared with two for Delta. Morse said the difference in den- sity, demand and distance from GVRD watermains were the decid- ing factors in where the stations will be installed. Meanwhile, environmental groups that banded together under the Lower Mainland Drinking Water Coalition, representing more than 20,000 people. have rejected the rechlorination option. Citing the hazards of more dun- gerous chlorine curgos transported on focal streets and chiorine’s potential toxic impact on the envi- ronment from chlorine spills, the group's spokesman, Justis Raynier, said ozonated water is the only option. “The public wants ozonated water (now). The GVRD staff time- CALL US: 983-2208 line ... appears exaggerated and is unacceptable. “The fight against chloramine has consumed countless hours of volunteer time, GVRD staff time and hundreds of thousands of tax dollars in consultant reports. “The consultants hired by the water district have presented infor- mation with a biased perspective and concerns have been raised that the costs of some options (ozona- tion) have been inflated to make them less palatable to the public.” Another leaflet distributed by an individual environmentalist quoted West Vancouver freshwater scien- tist, Dr. John Stockner, from the Department of Fisheries and Oceans, as saying: “Drinking water is better with all the bugs in it, We shouldn't be afraid of bacteria. It’s perfectly natural.” He said watersheds will regulate themselves without human interfer- ence. “You don’t need chlorine. What's frightening is the idea that it’s healthy to kill the bacteria in water with chemicals and then drink the chemicals.” In other business. two more staff recommendations were also endorsed by the water committee: @ Begin financial negotiations with B.C. Hydro for purchase of the Coquitlam Lake water rights: and Proceed with an environmental audit to determine locations of envi- ronmental vulnerability from sec- ondary infection and custs of miti- gation measures. water treatment and research. That left chlorine as the only viable option for secondary water disinfection. Worldwide, all secondary water disinfectants are chlorine or chlo- rine-based chemicals because they provide residual disinfection throughout water distribution sys- tems. In addition to chlorine and chlo- ramine, chlorine dioxide is used in such countries as France, Germany, Italy and Switzerland. ie & high In a December 1992 environ- mental impact assessment on sec- ondavy disinfection, the GVRD rejected chlorine dioxide because it is too expensive to produce and cre- ates byproducts that could pose a heaith threat. Other secondary disinfection techniques considered were ozone and ultraviolet radiation. In both these cases, the report stated that they produced little or no residual chemical presence in the water system. The report stated that ultraviolet radiation is only applicable on a small scale, Though the use of ozane ind fil- tration as a primary disinfectant is 54% to 10% more expensive than the chlorine system, there is flexibitity in the GVRD plan to add ozone at a tater date. There are other water purifica- tion techniques beyond what the GVRD considered, but they are suited primarily for small-scale purification systems, as opposed to large-.cale municipal disinfection systems, The difference, said Coquitlam purifier Howard Dickie, is that dis- infection is for one-use water, and purification is for recirculated water, Dickie’s company uses copper and silver ionization to purify swimming pools, spas, fountains, injection molding systems, and air- conditioning. “The copper effectively pierces the outer membrane of an algae spore for example and kills it; the silver tends to screw up the DNA process.” Dickie said the process does not produce harmful byproducts and has proved effective since the 1960s. While ionization is theoretically possible for the Lower Mainland’s water, he said it is highly implausi- bie. “You'd have to build giant reservoirs with recirculated systems with a holding (capacity) of proba- bly the better part of 24 hours before it is reused. Yeah, it will work ... but at what cost?” Dickie said. By comparison, ozone needs a contact time of 18 to 24 minutes to kil] bacteria. NEWS photo Cindy Goodman STANLEY CUP fever broke out for a timely road trip at the intersection of Ranger Avenue and Montroyal Boulevard in North Vancouver. HB Budget Beaters... 62 BB Business eens 53 @ Classified BI Doug Collins voc eee 7 @ Inquiring Reporter M Lifestyles. eee 59 @ News of the Weird ® North Shore Now BE SPOS west eseeeenseee 14 B TY Listings oe 45 Canadian Publications Mail Sales Product Agreement Number 0087238 THIS WEEK’S QUESTION: Do you think tolls should fund a new First Narrows crossing?