July 25, 2013 – 6:40am By SELENA ROSS Staff Reporter – Herald News
Expert: Contamination inevitable with hot weather, waste runoff
Kinsman Beach in Lower Sackville, shown Aug. 10, 2012, was closed to swimmers on Wednesday. (INGRID BULMER
Haligonians who want to dip a toe into a local lake this summer could be forgiven for raising an eyebrow.
On Wednesday, Kinsmen, Black Rock and Dingle beaches were closed for swimming.
Last week, it was Shubie Lake, Campbell Point and Government Wharf beaches. The week before it was Kearney Lake, Albro Lake, Sandy Lake and Long Pond. The list goes on.
Swimmers can expect more and more bacteria-related beach closures as summers get hotter, according to water quality experts.
The good news is that the problem can be solved, but not without a bit of effort.
“All those lakes have culverts going into them and then it rains. The dog feces and whatever in the streets goes right into the lake,” said Paul Mandell, a retired Fisheries and Oceans Canada scientist who has been studying Halifax-area lakes for decades, and still does consulting work.
“Effluence that wouldn’t cause closure in beaches (in the past) will because of the rising temperatures,” he said. “It’s been 35, 36 degrees here and that’s enough to cause E. coli to grow.”
Step 1, then, is for people to pick up after their dogs.
The other steps take a bit more long-term planning.
Stormwater pipes that feed directly into lakes via culverts are sometimes accidentally crossed with waste pipes, increasing the bacterial load, says Jocelyne Rankin at the Ecology Action Centre.
Owners of old cottages who aren’t properly managing their septic tanks also send bacteria-laden waste to nearby beaches, said Damon Conrad of the Sackville Rivers Association.
Bayswater Beach in Lunenburg County, a provincial beach, was closed because of bacteria for the first time ever this year. The province said the source of the bacteria was unclear.
There are several cottages upstream from the beach, said Conrad. There’s also a fish farm about half a kilometre away that has been there for several years.
Fish farms and pulp mills are both sources of contaminants, said Mandell. Other sources of bacteria could include fecal matter from agricultural runoff or from wildlife, said Rankin.
Combined with warmer water, any source of bacteria could become a problem, and many could be addressed.
People with septic tanks could research and install septic fields, or systems of trenches that naturally filter the waste, said Rankin.
When it comes to culverts, constructed wetlands next to lakes act as biofilters, said Mandell. There is one by Settle Lake in Dartmouth and they are not expensive to construct.
Local swimming water is not tested in a way that reveals sources of bacteria, so people aren’t likely to know if they’re polluting a local lake, said Rankin.
Halifax Regional Municipality spends about $10,000 per year testing its swimming beaches once a week, said spokeswoman Tiffany Chase.
From 2006 to 2011, the city invested $500,000 to sample water at 55 lakes three times a year as part of the regional plan. The results were published and used to guide future land use planning, but the program ended, she said.
Because the municipality and province generally do a minimum of testing, the problem is one for the public to tackle, said Mandell. He said he’d like to work with anybody interested in dealing with lake pollution.
“It’s very rare in this world to find an urban centre with such a beautiful suite of lakes,” he said. “People really have to take care of the lakes themselves. Every lake in Nova Scotia should have a society that samples the water and checks it out, especially with global warming.”
Most of the dozens of lakes within Halifax Regional Municipality have culverts going into them.
That means popular swimming spots without lifeguards, such as Williams Lake and Tea Lake, likely have similar conditions as others, but no warnings to the public when water is unsafe, said Mandell.
He said he believes Second Lake in Lower Sackville, Bell Lake in the Cole Harbour area and Lake Banook in Dartmouth are the only ones that are culvert-free.
Dollar Lake near Musquodoboit Harbour, which is part of a provincial park, is also a safe bet, said Mandell.
“I swim in Dollar Lake,” he said, “because there’s nothing going into it.”
By SELENA ROSS Staff Reporter