|
|
|||||
|
Residents in Sooke are concerned about the imminent tax hikes to pay for the new sewer system. |
|||||
|
Calendar of Events & Special Dates |
Where does that toxic stuff you put down the drain go - into the food chainVancouver Sun, October 25, 2001 By Scott SimpsonFlushing is start of toxic journey: No escaping daily load of chemicals entering Strait of Georgia, scientist discovers. Ken Hall has spent a lifetime tracking the flow of toxic materials through the waste streams of the Lower Mainland. Hall is the brains behind a landmark University of B.C. study that charted the ebb and flow of lead through the Greater Vancouver environment, via storm drains and illegal sewer connections in Burnaby's Brunette River system. But none of his previous work prepared him for the day he learned there may be no escape from the frightening and widespread threat that a group of chemicals pose each day in the Strait of Georgia ecosystem after they're flushed down drains in hundreds of thousands of Greater Vancouver homes. Hall's discovery came as he and some of his graduate students at UBC were researching one of the most ominous and frightening topics in environmental science -- the impact of endocrine disruptors on the reproductive and immune systems of humans and animals. According to the U.S. Environmental Protection Agency, endocrine disruptors have effects on wildlife and fish that include abnormal thyroid function, decreased fertility, decreased hatching success, demasculinization of fish, birds, reptiles and mammals, and alteration of immune systems. International research dating back more than 20 years shows that exposure to endocrine disruptors in sewage effluent can cause feminization of male fish. British researchers reported last year that these impacts on fish are so widespread that they're now noted in rivers right across Northern Europe. Closer to home, the compounds are suspected in the virtual extinction of Atlantic salmon in Eastern Canada and New England, in the decline of Lake Ontario trout -- and possibly in the recent discovery of sex-reversal in 84 per cent of wild male chinook in the Handford Reach of the Columbia River in central Washington. In the Strait of Georgia, endocrine disruption is cited by an international panel of scientists as a possible cause of the catastrophic die-off of Fraser River sockeye in each of the last five years. In each of those years, the migration abilities of late-summer/fall sockeye were compromised to the point that as few as three per cent of hundreds of thousands, and even millions, of salmon heading up the Fraser reached spawning grounds. A lot of the impacts on migratory fish such as salmon are subtle and scientists caution that it may be years or decades before we understand what is happening. Other impacts such as the tendency for these chemicals to reach ever-increasing concentrations as they work their way up food chains are already well established -- notably in Strait of Georgia killer whales which are virtual toxic waste repositories because of concentrations of PCBs in their bodies. PCBs are among the best-known endocrine suppressors and are particularly present in the marine environment. They were banned for most uses in North American in 1977. Endocrine supressors are common in sewage effluent, originally present in everything from soap, cleaning solvents and pesticides to nitrates, plastics and urine from women on birth control pills. In Greater Vancouver the Lions Gate primary sewage treatment plant has been identified by the regional district as a particularly troublesome source of some of these chemicals. Hall's plan was to find out -- under laboratory conditions, he thought -- how Georgia Strait salmon would respond when exposed to them. His experiment was intended to find out what impacts these chemicals could have on juvenile coho salmon, the most common species of salmon in Lower Mainland streams and throughout the Strait. To that end, he put trace amounts of an endocrine disruptor, nonyl phenol, into the food of a group of coho smolts. For contrast, a second group of coho smolts were fed food without the additive. The experiment was inconclusive -- but not because the fish getting the additive showed no signs of an effect. The problem was that the second group was also showing signs of having ingested nonyl phenols. It turned out that the food fed to both groups was already contaminated with the stuff. Subsequent analysis found it was present in both the krill that form the basic diet as well as a fatty acid that is added to supplement the krill. "We used krill from Chile. When that was analysed they found that it had some nonyl phenol in it. Whether it's picking it up out in the ocean, or when the Chileans process the krill, we don't know," Hall said. "The other thing is that they put a batch of omega fatty acids in this mash that they make the pellets out of, and that was contaminated with nonyl phenols as well." In other words, Hall concluded, the experiment was out of control before it even began. It is a discovery that bodes ill for the Strait, particularly because of the amount of these chemicals flowing into the Strait every day. "These are substances known to have some hormonal effects, and we use them all over the place," Hall said. "Look at all the stuff you put in your dishwasher every night to make your dishes sparkle. It just washes down the drain, loads of it every day." Sewage from over 200 sites representing 39 different industries or waste types is tracked for toxic substances discharging into the Georgia Basin, and on into the Strait. Those sites pump out everything from PCBs, arsenic, and lead to cyanide and chlorine. Some arrives in sewage from wastewater treatment plants, some from pulp mills, landfills, industries and households. Some comes from agricultural runoff. Some comes from the vast network of municipal storm drains that capture street runoff and transfer it to the sewer system -- and some arrives from storm runoff that is transferred into the Strait with no treatment or scrutiny. In some cases, information about the volume and origins of some toxics is impressive. But a recent Environment Canada study says in other cases certain groups of endocrine suppressors escape into the Strait undetected. The report on toxic substances in wastewater going into the Georgia Basin notes there are extreme inconsistencies in the way that the government agencies monitor them. Many such discharges are perfectly legal -- the Water, Land and Air Protection ministry licences all discharges going into rivers, requiring that the stuff pumped out does not exceed federal and provincial standards for concentration and volume of material. Agencies such as the Greater Vancouver regional district undertake daily samples of effluent taken from its five sewage treatment plants -- but rarely sample for the presence of endocrine disruptors. The Environment Canada study questions whether anyone is paying attention to the situation. For example, the study gave B.C's environmental protection ministry the lowest possible grade -- a zero -- for environmental monitoring because it couldn't provide information on the volume of toxic discharges to the Strait from sources including food processors, plywood plants, pulp mills, refineries, marine cargo storage, landfills and mines. The study acknowledged discharge data may exist in raw form, but said it is not accessible for evaluation. Although the streams feeding into the Georgia Basin are home to some of the world's most prolific salmon runs, the study said information about the quantities of endocrine disruptors going into the Strait is scant. Nonyl phenol compounds flow out of waste water treatment plants and raw sewage pipes at "maximum concentrations 20 to 30 times the lowest levels known to cause adverse effects to fish," says the study, which recommends toxic chemicals such as those found in Ken Hall's fish food should be placed on a high priority list for regular monitoring. It also says sources of the compounds should be identified and controlled -- noting that over 11,000 kilograms of phenols were used as a wetting agent in pesticide applications by farmers in the Georgia Basin in a single year. "Why we're doing all this, the ultimate reason, is that we are trying to look at the toxicity of chemicals, their persistence in the environment, and the amount of the chemical that's getting into the environment. Those are the three factors you have to evaluate in order to determine the risk," says Environment Canada toxics expert Doug Wilson. "Some substances like PCBs (polychlorinated byphenyls) are known endocrine disruptors and we know a lot about them. But there are newer compounds around where we have to get more information on concentrations in the environment. "Basically the effects on the environment of a lot of these things still have to be researched. What's the effect on the biota, everything from invertebrates to whales? There has to be more research, more literature reviews looking at the sources, concentrations and loadings coming from the sources, identifying the priorities." It would be a mistake to continue to rely on the traditional approach to sewage disposal, and assume that the tidal action of the Strait of Georgia will simply dilute toxic discharges to the point that they are not harmful says Rob MacDonald, a federal researcher with the Institute of Ocean Sciences in Sidney. He says the concentration of PCBs in killer whales is proof that, even at the most minute dilutions, endocrine suppressing toxins climb to the top of the food chain. Hall says studies conducted to date on toxic sewage discharges going into the Strait have failed to provide a clear image of what's happening out there. "All of these studies are done independently, looking at one particular outfall and things like that," Hall says. "I think the big issue is -- what are the cumulative effects of all these outfalls and the non-point sources on the whole Strait of Georgia?" And following up on that story - hours, not days, at LC 50 Vancouver Struggles to Solve Toxic Sewage Problemsfrom the Vancouver SunIf there were ever any lingering doubts about the lethal threat that Greater Vancouver sewage poses to marine life in the Strait of Georgia, they vanished in one of the grimmest endurance tests ever devised to calculate the deadly effects of water pollution. Under the watchful eye of a technician in a Vancouver laboratory, a cluster of finger-length rainbow trout immersed in a tank of effluent from two of Vancouver's primary sewage treatment plants gasped for life, their mouths opening and closing in a desperate effort to get more oxygen from the water they forced through their gills. A standard test to measure toxicity in sewage requires that the fingerlings -- serving much the same role as canaries in a coal mine -- be immersed in the effluent for 96 hours. If more than 50 percent die, it's assumed that the effluent would be toxic to fish once it's pumped into the marine environment -- and there's grounds for possible prosecution. There would be no passing grade for the Iona and Lions Gate sewage treatment facility. |
||||
|
|
|||||
Email WRATH