Desired Outcome: Drinkability

SOLEC Assessment

SOLEC's overall subjective assessment of Drinkability of waters in the Great Lakes ecosystem is "Good", the highest rating under the SOLEC scale. This assessment is described in the SOLEC report as, "The state of the ecosystem component is presently meeting ecosystem objectives or otherwise is in acceptable condition."

Basis for SOLEC Assessment

Data were collected from 22 cities that obtain their drinking water from Great Lakes surface water.⁴ SOLEC presented summary results on five key factors: turbidity, organic matter, pathogens, chemical contaminants, and taste and odor, which are the stated measurements for this indicator.⁵

Commission Assessment

The Commission concurs with the subjective assessment of "Good" for the surface water of the Great Lakes as a source of treatable drinking water. It also recognizes the heightened concern regarding the safety of drinking water from all sources following tragic events arising from outbreaks of cryptosporidium and E.coli.⁶ In this regard, the Commission is pleased that the SOLEC organizers are expanding data collection to include cities that depend on groundwater and tributaries as sources for drinking water.

Indicator Challenges

As an indicator, the condition of raw water going into a treatment plant reflects the local water conditions as well as the overall state of the Great Lakes. Raw water quality also may influence the cost and extent of treatment required in order to meet drinking water standards.

The challenge of applying indicators to the desired outcome of Drinkability is to develop a uniform reporting format in each country and undertake quantitative assessments of the information gathered. This situation is improving as more water treatment plants report results based on standard protocols and implement electronic data storage. Considerable effort will be required to report on temporal and spatial trends of the quality of the raw water.

The above SOLEC indicator focused on surface water. The public is interested in the quality of their tap water. This can be adversely affected by the quality of the source water (surface or ground water), the quality of the treatment process and the quality of the distribution systems, which in some communities are aging.