The Revised Alberta Surface Water Quality Guidelines

Alberta has revised and published surface water quality guidelines (ASWQG) that affect Sylvan Lake.

Notable changes are that the previous recommended nutrient limits for Total Phosphorus (0.05 milligrams per litre, mg/L) and Total Nitrogen (1.0 mg/L) have been withdrawn. See the extracted text here:

ASWQG-Nutrients & Aesthetics-ab.gov-2014-07-11

One more locally-endorsed reference does exist as a protective standard for Sylvan Lake. The Cumulative Effects Management System joint project of AESRD and the Sylvan Lake Management Committee proposed a stricter guideline of 0.035 mg/L for Total Phosphorus while retaining the established guideline of 1.0 mg/L for Total Nitrogen. As these are recommended values they have no firm standing for regulatory purposes.

The 2014-07-11 Alberta Surface Water Quality Guideline revision has replaced a barrier with a “narrative”, a less rigid, more flexible, read-and-react requirement for surface water management and protection.

That new approach seems to be equivalent to removing all speed limits on highways with the governing qualification being: “drive as fast as you want to, as long as you don’t have an accident”. If you then experience a high speed collision (or if Sylvan Lake becomes a chronically turbid green water body during the summer recreational season) then it wouldn’t really matter what the regulatory standard or guideline used to be.

Whether Sylvan Lake has a hard or soft specification for nutrient content, the lake itself will evolve in response to the real world environmental variables that include the set of fluctuating nutrient concentrations that are tracked in ALMS Lakewatch reports and in the Alberta water quality database. A “nutrient narrative” may give more short term comfort to municipal land use planners and developers than may a measurable progression towards hard regulatory limits. However, impaired water bodies like Lake Erie, Lake Winnipeg, America’s Chesapeake Bay, and the Australia’s Great Barrier Reef would respond with regret to their own “narratives” if they could. In those well documented cases it is too late to hope that there will be no catastrophic change.

Nevertheless, if and when excessive blue-green algae and cyanobacterial growth in Sylvan Lake hits the watershed fan, the rolling hopeful scenario of the pre-narrative will likely change quickly to inform property owners and watershed visitors about their property-values, self-protection, and public safety. In that case, any remaining aquatic life will have to defend itself because the watershed public will probably be preoccupied with relocation rather than restoration. The post-narrative experience will be one of regret about change, and memories of “the good old days” of clean, clear water:

CPB-Allison K-v2

Best Practice instruction submitted to a SLWSS contest by an elementary school student.

As a reminder, here are four decades of Total Phosphorus (TP) and Total Nitrogen (TN) concentration data compared to the previously recommended red line limits of 0.035 mg/L and 1.0 mg/L respectively.

TP and TN Time Series

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