UPDATE: Arsenic in Rosslyn Village Drinking Water System

Municipality of Oliver Paipoonge                                                                              May 2, 2023

Arsenic in Rosslyn Village Drinking Water System: UPDATE


Since March 9, 2023 the Rosslyn Village Drinking Water System has been subject to a Drinking Water Advisory issued by the Thunder Bay District Health Unit (TBDHU) due to high levels of arsenic.  Under the Advisory water is not to be consumed, even if it is boiled.  Please click the link below to access an information brochure on arsenic published by Health Canada.

On March 28th municipal administration had a meeting about the situation with representatives from the Ministry of Environment, Conservation and Parks (MECP), TBDHU and Ontario Clean Water Agency (OCWA), which is the operator of the system contracted by the Municipality.  MECP said the arsenic needed to be brought down to an acceptable level.  Referring to cases of high arsenic with other Ontario water systems MECP suggested that since the Municipality is already chlorinating the water, filtration may work to remove the excess arsenic.  While there are other treatment options like ozone and reverse osmosis, they are more costly.  In other Ontario jurisdictions with high levels of arsenic filtration with 1 micron (one millionth of a millimetre) filters after chlorination was found to reduce arsenic to acceptable levels.  During the conversation it was identified that the Rosslyn system currently only employs 30 micron filtration. Municipal administration agreed to explore the filtration option.

On April 11th Council approved a proposal from OCWA to conduct a pilot project to see if filtration could work to reduce the high arsenic levels.  Following OCWA’s recommendation on April 20th the Municipality requested services from the Walkerton Clean Water Centre (WCWC).  The WCWC has the expertise and facilities to investigate water quality problems and explore solutions to overcome the problems.  Recently the WCWC has had success with removing arsenic from communal well water systems.

Municipal administration had a meeting with representatives from OCWA and WCWC on April 27th.  The participants talked about how the testing process works in general and making arrangements to get our project started.  The first step is analysis of our system setup and testing data by the WCWC.  OCWA supplied that information to WCWC on May 1st.  If WCWC finds the testing data to be inadequate for its purposes, water from the Rosslyn system would be sent to Walkerton for analysis by WCWC. 

Once WCWC has acquired a good understanding of our water system and its water it will determine treatment options to reduce the arsenic to acceptable levels.  After further consultation with OCWA and the Municipality the WCWC would draft a proposal to construct a model treatment system that would fit on a skid.  If the proposal were accepted by the Municipality, the system on the skid would be shipped to Rosslyn to be tested.  If the model treatment system worked to reduce arsenic levels and a full scale treatment system was determined to be feasible and effective, the Municipality could explore having a full scale treatment system designed and constructed.

At this point it is uncertain how long the pilot project to investigate treatment solutions will take.  At the April 27th meeting the WCWC representatives explained they have a large number of projects already in process but they realize the Drinking Water Advisory elevates the need to expedite our project.  Nonetheless it may still take several months to complete our project.  Once that is done, at this point it is unknown how long it will take to get a full scale treatment system designed, constructed and operational.

Another element of this matter is financing.  How costs will be covered is yet to be determined.  Council will need to grapple with financing as cost forecasts become available.


Health Canada: It's Your Health - Arsenic In Drinking Water


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