The tests may be clear but chlorine continues to be added to Chilliwack's drinking water system "until further notice."

Last Thursday, a day after Chilliwack's emergency chlorination system was turned on for the first time ever, and two days after a meeting to discuss secondary disinfection of the city's drinking water, resampling for E. coli came back clear.

A low level of E. coli bacteria was confirmed from a test site at South Sumas and Sumas Prairie roads in Greendale last Wednesday.

After the positive test, city crews immediately flushed the pipes and activated the standby chlorination system. Crews were out again Thursday morning to flush the pipes again and resample the water as per protocol.

The use of the standby chlorination system in the main water distribution system means the entire city, not just Greendale, now has chlorinated water.

"Unfortunately this is unavoidable," a note on the city's website says.

Director of public works Glen MacPherson said he is currently overseeing an investigation into what might have caused the positive test result. Once that investigation is completed, the results will be passed on to the Fraser Health Authority (FHA), which has the final say on turning off the chlorination.

MacPherson said he couldn't comment on if the chlorination could extend days, weeks or months.

And while the current chlorination is being done with an emergency system, and that system is not designed for full-time use, MacPherson said it could very quickly be converted.

The positive E. coli test elicited shock, surprise and even a little suspicion among residents as it came less than 24 hours after hundreds of residents attended a meeting to give FHA bureaucrats a piece of their mind about a chlorination edict issued Feb. 5.

Chief medical health officer Dr. Paul Van Buynder told residents that Chilliwack has a great source of drinking water but that secondary disinfection is the only way to ensure the end product will always be safe.

"We need more than just really good water in the ground," Van Buynder said. "We need really good water at the tap."

A petition against water chlorination at www.chilliwackwater.com had more than 4,400 signatures by Monday afternoon. Some tips on reducing the taste and odour of chlorine in tap water from the city's website:

? The simplest thing you can do is to fill a jug with water and keep it in the fridge for drinking. Much of the chlorine will leave the water if left overnight. Cold water also tastes and smells better than water at room temperature.

? Using a water jug with a filter, such as a Brita filter jug, will remove the chlorine from your water and the jug can be kept full in your fridge. Water can be drank as soon as it has filtered into the jug.

? There are various faucet-mounted water filters available at most home improvement and department stores. These filters simply attach onto your existing faucet and chlorine is filtered from the water as it comes out of the tap.

phenderson@chilliwacktimes.com