Desalination and reclamation of water are highlights at Toronto conference
July 5, 2007
By Canadian Consulting Engineer
Toronto saw 12,000 people involved in the water industry descend on the city on June 24-28. Held June 24-28, the A...
Toronto saw 12,000 people involved in the water industry descend on the city on June 24-28. Held June 24-28, the American Water Works Association’s annual conference “ACE07” drew crowds from across North America and the world, enough to make even the cavernous Metro Toronto Convention Centre seem crowded. Attendees were everyone from operators, to scientists, manufacturers and engineers, with a sizeable Canadian presence as well.
One major theme was the increasing pressure being put on water resources by rampant development. It seems that some of the driest areas of North America are those where most people want to go and live, leaving water utilities scrambling to keep up with demand without depleting and degrading their aquifers.
Water reuse and recycling, as well as new technologies such as desalination, were therefore a hot topic among the hundreds of sessions. In “Quenching Maui’s Thirst: is Desalination the Answer,” for example, Martin Steinpress of Brown and Caldwell explained how the U.S. consultants had been brought to the Hawaiian island to figure out new sources of potable water and whether it was better to use brackish groundwater from deep wells or extract seawater for desalination. The problem in Maui arises because people want to live on the drier leeward side of the island and in the central lowlands, rather than where there’s lots of rain, he explained. The tide of development in those drier areas is “explosive,” similar to what’s taking place in California and the southwest states. But existing water sources on Maui also have to serve as agricultural irrigation for the sugar cane and pineapple crops and the indigenous people want demand reduced and the water systems restored.
Another presenter, Trevor Hill of Global Water Management LLC, spoke of the water shortages in Arizona and the solutions they are promoting to force new housing developments to use reclaimed water for watering their lawns and gardens. Similar to dual plumbing schemes that have been used in Sydney, Australia (see “What Goes Around, Comes Around,” CCE June-July 2006), Hill explained that new housing developments in the town of Maricopa, a city of 16,000 south of Phoenix, have pressurized recycled water to every home, and that the reclaimed water is used for toilet flushing in public schools and commercial buildings. Generally, he said, it has been easy to convince the developers to build the impoundment ponds, because they make an attractive neighborhood feature. Hill is a Canadian who now works in Arizona, and said he’d again been struck on his visit to Toronto and his stroll by Lake Ontario that day on how abundant the water resources are in Canada compared to his new home state. In Arizona, for example, they have had 12 years of record low rainfalls, he said, and yet “still they are building golf courses at tremendous rates.” The influx of people to Arizona continues unabated because land and housing is cheap. Maricopa had 900 new homes built in a single month, he said, and an average growth of 10% of the existing housing stock. With the increasing water demand and river flows drastically reduced, the authorities have no choice but to find ways of recycling and reclaiming existing resources.
But Canada is not without its water resource problems, as a presenter in the Canadian Affairs Committee Track showed. Neal Klassen of Kelowna Water Smart spoke passionately against the prosperous householders who live up on the hills above the B.C. city and persist in watering their lawns to a vivid green despite the semi-arid climate. Metering has shown that water consumption is five times higher in summer in the winter, so they know that the demand on the potable water supply is largely going on residential grass. They have encouraged water conservation through measures such as low flow fixtures, etc., but they realized that “grass is the enemy” because it sucks up so much water. The Kelowna city council consequently have adopted seven steps to alleviate the situation, including making development approvals tied to landscaping measures that reduce the demand for water. Standards will require an adequate soil base for lawns, the use of appropriate drought-tolerant plants for the climate, and standards regarding the spacing of sprinkler heads. The only challenge will be implementing the standards, admitted Klassen.
Again the factor driving the politician’s new concern with water shortages is rampant development. Kelowna has seen a 25% growth in population over the last eight years, and this tends to be people expecting a very high standard of living. The city has the second average house price in Canada, second only to Vancouver.
On the other extreme, too much rather than too little water can be a problem in other places of B.C. Another sessions in the Canadian track was a presentation by Douglas G. Neden of the Greater Vancouver Regional District who described the lessons the water authority had learned from Canada’s largest ever boil-water advisory that occurred last November due to the extreme turbidity in the supply lakes after heavy rainstorms pounded the region. Neden talked about how they hope such problems will be minimized once the new Seymour-Capilano filtration plant is operational, scheduled for 2008.
Paul Wobma of CH2M Hill presented another major new Canadian water treatment plant, the Winnipeg water treatment plant project that the company is designing with Earth Tech and UMA.