Government of British Columbia: Ministry of Environment: Water Quality Guidelines for Mercury
Ambient Water Quality Guidelines for Mercury
Overview Report — First Update
Prepared pursuant to Section 2(e) of the
Environment Management Act, 1981
Original signed by Margaret Eckenfelder
Assistant Deputy Minister
Environment and Lands HQ Division
February, 2001
TABLE OF CONTENTS
Summary
Tables
Preface
Introduction
Recommended Guidelines
Application of the Guidelines
Summary
This report is one in a series that establishes ambient water quality guidelines for British Columbia. The guidelines are safe conditions or levels of contaminants, applicable province-wide, which are set to protect various water uses.
This report updates the 1989 BC Environment guidelines for total mercury (THg) by providing revised water quality guidelines to protect aquatic life from chronic effects of mercury. This was deemed to be necessary since the Canadian Council of Ministers of the Environment (CCME) have recently developed guidelines for mercury in the water column to protect aquatic life and in the flesh of aquatic life to protect wildlife. The report also outlines water quality guidelines to protect avian wildlife feeding on aquatic organisms. The updated guidelines are consistent with the CCME tissue residue guideline to protect wildlife from methyl mercury (MeHg) in their diet. The guidelines for drinking water, livestock, irrigation and recreation, are unchanged from in the 1989 report. The guidelines are summarized in Table 1, Table 2, and Table 3.
A major use of the guidelines is to set ambient water quality objectives. The objectives are the guidelines modified or adopted to protect the most sensitive designated water use in a particular body of water. The objectives are used in the preparation of waste management Permits, Orders, or Approvals, which are the only documents to have legal standing. The objectives, however, are not usually part of these documents.