New Lead and Manganese Maximum Acceptable Concentration (MAC) Guidelines

posted on Mar 21 2019

On March 8, 2019, Health Canada published a new maximum acceptable concentration (MAC) for lead, and a new MAC for manganese can be expected for April 2019. MACs are set and revised if appropriate and published under Health Canada's Guidelines for Canadian Drinking Water Quality. 

The new MAC for lead is 0.005 mg/L (milligrams per litre), a lower value than the current 0.010 mg/L. The expected MAC for manganese will be 0.12 mg/L.

Alberta Environment and Parks (AEP) uses the Guidelines for Canadian Drinking Water Quality to set drinking water quality objectives in Alberta. So what does this mean for Alberta drinking water systems?    

  1. Municipal water providers will have five years after receiving written notification from their AEP regional Environmental Protection and Enhancement Act (EPEA) signing Director to develop and begin implementation of lead and/or manganese management programs for their systems.
  2. Water utilities will be required to submit their plans for meeting the MAC for lead (at the tap) and manganese (in the distribution system) as part of their annual drinking water system report to AEP and to include the plans in their Operations Program.  
  3. Current monitoring programs may need enhancement to assess the presence and concentration of lead and manganese in water. Monitoring for lead will require water sampling at the tap within buildings because lead concentrations can be affected by plumbing fixtures and building service lines. AEP will be providing guidance documents on water sampling protocols for lead (at the tap) and manganese (in the distribution system and source water).

Once drinking water systems characterize their lead and manganese risks, the next step will be to develop mitigation plans if necessary. AEP, in conjunction with Alberta Health and Alberta Health Services, will be providing guidance on how consumers can reduce their exposure to lead and manganese in drinking water. 

If you have any questions contact your regional Drinking Water Operations Specialist (DWOS) at AEP.