Section 9: Pollution from Contaminated Ground Water (Annex 16)

Observation

Millions of basin residents rely on groundwater for basic water supplies,¹ yet there is a serious lack of information on groundwater quantity and quality in the Great Lakes basin. Given the threat of contaminated groundwater to human health, as illustrated by the recent Walkerton, Ontario tragedy, and to the health of the Great Lakes basin ecosystem,² there is a critical need for more information on groundwater quality and quantity.

Groundwater issues were recently highlighted by the Commission in its 2000 report, Protection of the Waters of the Great Lakes.

Discussion

Groundwater contaminants of concern³:

• Pathogens (bacteria/viruses)
• Nutrients (nitrate)
• Pesticides (triazines, DDT/DDE, Mirex)
• Chlorinated solvents (trichloroethylene)
• Petroleum products (BTEX, MTBE)⁴
• De-icing compounds (road salt, glycol)

In the 1987 amendment to the Great Lakes Water Quality Agreement, the Parties agreed to identify sources of contaminated groundwater affecting the Great Lakes, map hydrogeological conditions, develop standardized approaches for sampling and analysis to support Remedial Action Plans and Lakewide Management Plans, control groundwater contamination, and report progress to the Commission biennially beginning in 1988.

Contaminated groundwater is polluting surface water due to direct, ground to surface withdrawals by people and through passage of contaminated water into tributaries to the Great Lakes or directly into the Great Lakes. Many Areas of Concern, such as the Maumee and Niagara rivers, are contaminated by groundwater and require serious attention to ensure restoration of beneficial uses.⁵

Citizens of the basin have expressed considerable concern about the potential impact of large scale, intensive livestock farming on the quality and safety of groundwater and surface water. Article VI, Section 1(e)(ii) of the Agreement, calls for "measures for the abatement and control of pollution from animal husbandry operations, including encouragement to appropriate agencies to adopt policies and regulations regarding utilization of animal waste, and site selection and disposal of liquid and solid wastes, and to strengthen educational and technical assistance program to enable farmers to establish waste utilization, handling and disposal systems."

The methods and approach to mapping hydrogeological units are well developed. Nevertheless, there is a lack of such mapping, and far more detailed information about groundwater and the use of groundwater in the basin is needed. Data on withdrawals varies in quality, and data on consumption are extremely limited.

State, provincial and local government attention to the monitoring and regulation of groundwater withdrawals is especially warranted when climate change models are considered.⁶ Protection of groundwater recharge areas is the most efficient and cost-effective way to preserve groundwater quality.⁷

Because groundwater and surface water frequently interact, and it is impossible to distinguish between them in some instances, governments could be proactive and apply the precautionary principle (err on the side of caution) with respect to removals and use of groundwater in the basin. Land conservation programs within the 2002 U.S. Farm Bill offer incentives to protect water bodies from pollution.

Recently announced initiatives and new funding for groundwater monitoring and protection are welcome.⁸ Additionally, progress by governments in controlling the 26 most egregious sources of surface water contamination from contaminated groundwater along the Niagara River is commendable.⁹

Until new and proven technologies can be applied, these efforts will need to be sustained. More remediation sites will need to be added to ensure that the intent of Annex 16 is achieved.