Effective 1st April 2016, due to a shortage of funding, CEMA suspended operations until further notice. 

For information, contact Dan Stuckless, CEMA President: Dan dot Stuckless at

The NOx-SO2 Management Working Group (NSMWG) of the Cumulative Environmental Management Association (CEMA) was formed with the objective of developing and recommending a management plan (framework) for oxides of nitrogen (NOX) and sulphur dioxide (SO2) emissions as they relate to acid deposition, and subsequently eutrophication and ground level ozone.

The Framework will provide a system for managing emissions of oxides of nitrogen (NOx) and sulphur dioxide (SO2). The goal of the framework is to maintain the chemical characteristics of soils and lakes to avoid adverse effects on ecosystems, plants, or animals in the management area. Acidification management objectives, in support of this goal, are defined for soils and lakes in terms of limits in chang to monitored and model-predicted soil and water chemistry.

The purpose of the management objectives is to limit changes in soil and water chemistry to provide protection to biological systems. The framework is based on the following conceptual acidifying emissions management approaches:

  • reasonable, cost effective measures in the design and operation of projects to minimize acidifying emissions. This will include the evaluation of Best Available Demonstrated Technology2 (BADT) in new project design, existing project expansions, and equipment replacement;
  • monitoring and predictive modeling to verify that acidification beyond limits (management objectives) identified in the management framework is not occurring and has a low risk of occurring;
  • emissions management to prevent further increase in emissions, or reduce existing emissions, if management objectives regarding acidification effects are not achieved; and
  • ongoing monitoring and research to validate or improve the ecological assumptions and data underlying the assessment of acidification risk.

The management framework will be implemented in three stages, with immediate implementation of an initial framework. This initial framework will be revised after approximately two years to incorporate the results of short-term research projects, which will be completed at that time. These projects are focused on improving the reliability of acidification effects predictions by the models used for this purpose in the initial implementation of the framework. The framework will be further revised after approximately six years, when the results of several long-term research projects will be available. These projects focus on selection of better predictive models and collection of regional data inputs required by these models.

Framework Report

icon Acid Deposition Management Framework