March 11, 2014 12:00 AM
Despite fears that the cloudiness of China Creek could be harming Port Alberni’s water supply, the current treatment system prevents turbidity levels from affecting what comes out of resident’s taps, says city engineer Guy Cicon.
Correspondence between the City of Port Alberni and the Ministry of Forestry, Lands and Natural Resource Operations has brought up concerns that forestry harvesting and the building of roads near China Creek is causing water to be more turbid, or cloudy, making treatment more difficult. Along with Bainbridge Lake, China Creek is one of Port Alberni’s two water supplies.
A letter dated Jan. 20 to the ministry from Mayor John Douglas cites a 2011 provincial report on the China Creek watershed. That study states that most of the watershed’s turbidity has been caused by natural factors.
Between 1998 and 2005, there were 142 landslides in the watershed; 95 due to natural causes while 23 were caused by logging activities and road construction caused another 24.
“Landslides have been attributed to both logging and roadwork,” stated Douglas in the letter. “While these figures and descriptions are not alarming, they affirm our belief that forestry-related activities remain a primary driver of turbidity due to the runoff and sediment production.”
The city currently uses a chlorine system to treat water from China Creek and Bainbridge Lake. This treatment process can be hindered when water becomes too cloudy.
“Elevated turbidity levels can decrease efficiency of disinfection,” said Cicon. “Pathogens can be imbedded in the [turbid] particle if it’s too big and the efficiency of the chlorine isn’t as high.”
But Cicon said the current water treatment system brings no need for alarm. Bainbridge Lake, which has a low turbidity level, serves as a backup if China Creek becomes too cloudy for treatment. The city plans on adding the minimally turbid waters of Sproat Lake as a third source in the future.
“When it rains the turbidity in China Creek increases because of the runoff, but in Bainbridge Lake it doesn’t,” Cicon said. “When the turbidity is high in China Creek, we just switch to Bainbridge Lake. So effectively turbidity isn’t a concern for the drinking water users because we have the backup system.”
The provincial report states that the overall quality of water in China Creek is very good – except for the level of cloudiness in the supply.
“All chemical, physical and biological parameters meet provincial water quality guidelines with the exception of turbidity and Escherichia coli, which exceeded the drinking water guidelines on occasion,” read the province’s report on the China Creek watershed, adding that the effects on water turbidity will decrease as harvesting practices continue to improve and areas are reclaimed.
Part of the China Creek Watershed is privately owned by logging companies, with 5,327 hectares managed by Island Timberlands and another 401 hectares handled by TimberWest.
In an interview last week with The Times, Douglas said that the city has been developing a better relationship with the ministry and logging companies to make sure that forestry practices don’t affect water turbidity. He also said that the involvement of groups of citizens, such as the Watershed Forest Alliance, is important to ensure forestry practices are responsible.
“We want to make sure we have a really good relationship with the industrial sector but we need to make sure that it doesn’t affect our water,” Douglas said.
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