This manual describes procedures for setting water quality-based effluent limits
for industrial and municipal discharges in Alberta.
The rationale for adopting more stringent water quality and technology limits is
discussed. Background information is provided on how effluent limits are calculated
from existing or desired long-term effluent performance and how substance variability
and sampling frequency are factored into the process.
The basis for in-stream guidelines is reviewed in the context of acute and chronic
values, duration and frequency of compliance. Concepts of design or worst-case
conditions and reasonable potential to exceed in-stream guidelines are introduced,
along with wasteload allocation principles and the subsequent development of end-of-pipe
The relative advantages and disadvantages of steady state and dynamic models for
single and multiple discharge scenarios are reviewed. Examples of applying the methods
described are provided throughout the text.
Updated: May 28, 2018