Public Forum on Great Lakes-St. Lawrence Water Quality

Workshop on Source Water Protection

13:30~17:00 Friday, October 19, 2001

Call 519-257-6703 for more information

13:30

Introduction

James M. Haynes, SUNY College - Brockport, New York

13:35

Isabelle Giroux, Impact of pesticide use on the water quality of the St. Lawrence tributaries. Quebec Ministry of the Environment, Quebec City, Que.

Selon le bilan des ventes effectué en 1997 par le ministère de l'Environnement du Québec, 3,3 millions de kilogrammes de pesticides sont utilisés chaque année, dont 80 % pour l'agriculture. C'est la production du maïs qui mobilise les plus grandes superficies traitées et la plus grande quantité de pesticides, en majeure partie des herbicides. Depuis 1992, on a décelé la présence de nombreux pesticides dans vingt cours d'eau. En 1998, des herbicides comme l'atrazine, le métolachlore, le bentazone , le 2,4-D, le dicamba et le diméthénamide étaient présents dans plus de la moitié des échantillons prélevés. Les dépassements de critères de qualité de l'eau et la détection simultanée de 10 à 15 pesticides dans ces cours d'eau suscitent des inquiétudes concernant la santé des organismes aquatiques et la qualité de l'eau potable. Parmi les autres cultures documentées, on a également décelé des herbicides, des insecticides et des fongicides dans des cours d'eau voisins de vergers de pommiers, et de cultures maraîchères. En outre, les eaux souterraines de champs de culture de pommes de terre contiennent des nitrates en concentrations qui dépassent souvent la norme d'eau potable ainsi que de faibles concentrations de pesticides.

The 1997 inventory by the Quebec Ministry of the Environment indicated that 3.3 million kg of pesticides are used annually, 80% of which are used in agriculture. The largest amount of land and greatest quantity of pesticides (mostly herbicides) are associated with corn production; a large number of pesticides have been detected in 20 rivers since 1992. In 1998, herbicides such as atrazine, metolachlor, bentazone, 2,4-D, dicamba and dimethenamid were detected in more than 50% of the samples. Detection of some products in concentration exceeding the water quality guidelines and the simultaneous detection of 10-15 pesticides in these rivers raises concern for the health of aquatic life and the safety of drinking water supplies.

Other water monitoring programs in stream and drainage ditches initiated around apple orchards and vegetable growing regions showed presence of herbicides, insecticides and fungicides. Concentrations of nitrates exceeding the drinking water guideline and low concentrations of pesticides have also been detected in groundwater of potato growing areas.

14:00

Donna Myers ¹ , Mary Ann Thomas ¹ and Jeffrey W. Frey ² , Contaminants in stream water and ground water in the Lake Erie-Lake St. Clair Drainages and implications for source-water quality. ¹ U.S.Geological Survey, Columbus, OH and ² U.S. Geological Survey, Indianapolis, IN.

Water quality in the Lake Erie-Lake St. Clair Drainages, USA, is greatly influenced by land use and human activities. Herbicides such as atrazine, acetochlor, cyanazine, metolachlor, and simazine were detected in 50 to 100% of all stream-water samples collected during 1996-98. Elevated pesticide concentrations in streams persisted for 4 to 6 weeks after applications in agricultural and mixed-land-use areas. Herbicide and nutrient concentrations in several of the streams sampled were in the top 25% of streams monitored nationwide by the U.S. Geological Survey's National Water-Quality Assessment Program. The number of detected contaminants was greater in large streams draining several land uses than in small streams draining a single land use.

Aquifers in glacial deposits near the land surface are the major ground-water source of drinking water in urban and agricultural areas of northwestern Ohio, northeastern Indiana, and southeastern Michigan. In residential areas in this region, more than 75% of the "young" ground waters have been affected by human activities, as evidenced by elevated concentrations of chloride and nitrate. Probable sources are septic systems, roads, and lawns, even though pesticides used on lawns and along roadways were rarely detected. In agricultural areas, elevated nitrates, herbicides, and herbicide breakdown products were detected in almost 60% of shallow wells. Probable sources are agricultural chemicals applied to cropland.

Overall, 30 different pesticides in mixtures of 2 to 18 compounds were detected in samples from the region's streams and ground water. Occurrence of multiple contaminants in streams and ground water is common to more than 50% of samples collected in the Lake Erie-Lake St. Clair Drainages. Drinking-water standards have been established in the United States for only 14 of 88 the pesticides analyzed for in this study, and no standards apply to mixtures of compounds. Although drinking-water standards were not exceeded on an annual basis, pesticide and nitrate concentrations were elevated seasonally in some streams. These findings show that land use and chemical applications to the land can degrade the quality of source waters used for drinking-water supply.

14:25

David Sharpe, The role of 3-dimensional hydrostrati-graphic mapping in support of groundwater protection, Oak Ridges Moraine area, Ontario. Geological Survey of Canada 601 Booth St., Ottawa, Ontario K1A 0E8

The Oak Ridges Moraine (ORM) is a provincially significant aquifer system that is under increasing pressure from rapid urban expansion. Consequently, there is a need to better understand how this water resource system works in order to make wise land-use decisions. Groundwater flow through sandy ORM sediments provides up to 50 % of dry-weather flow or base-flow to adjacent streams and rivers. Storm runoff, mainly from adjacent till plains, provides most of the remaining streamflow. Groundwater is also important in supplying water to more than 250,000 people in the Greater Toronto area. Recent research in the area has focused on describing the regional geological and hydrogeological framework so that the groundwater flow system and links between groundwater and surface water may be understood.

Investment in regional geological mapping is a form of proactive research in support of surface-groundwater protection. Three-dimensional geological mapping is an essential component of understanding regional groundwater flow systems and managing the groundwater resource. Basin analysis provides the methods to map the surface and subsurface geometry and connection of strata and water levels. For example, maps of sediment properties, thickness, continuity and depth to water table provide insight into groundwater flow and can be used to help identify potential water protection areas. Regional three-dimensional hydrostratigraphic mapping such as that carried out in the ORM is an important step in acquiring the knowledge required to carry out effective land use planning in support of water protection.

14:50

Douglas "Dusty" Hall , Successful implementation of Dayton's Source Water Protection Program . City of Dayton, 101 West Third Street, Dayton, Ohio 45401

The sole source of drinking water for the city of Dayton, Ohio is a trillion-gallon underground reservoir known as the Great Miami Aquifer. The City taps this aquifer to provide potable water to about 440,000 consumers in the Dayton region. In 1926, Dayton's first land-use plan promoted industrial growth along the rivers and above this vulnerable aquifer. In the mid-1980s, citizens became aware of the potential conflict between established land uses and the protection of drinking water quality. Citizens, business leaders and local government leaders worked together to develop and implement Dayton's Well Field Protection Program to ensure the long-term safety of the city's drinking water.

This Program balances regulatory and non-regulatory strategies. A unique zoning law controls the types and quantities of hazardous materials present on business premises, and compliance is monitored by professional staff inspectors. A network of over 125 wells is used to provide early warning of groundwater contamination and an extensive emergency capability is in place in the event a response is necessary. PROGRESS (Promoting Regional Opportunities for Growth Recognizing Environmentally Sensitive Settings) provides economic incentives and marketing to promote the transition of business activities from high-risk to "groundwater friendly" uses.

Since its implementation almost 13 years ago, Dayton's Well Field Protection Program has been honored with state, national and international awards and has been cited by the U.S. Environmental Protection Agency as a model for the nation. Dayton's success is the result of a responsive local government moving forward to address a pressing community priority. Source water protection became a community priority when citizen and business leaders as well as source water protection advocates fostered community-wide awareness and a commitment to proactively address threats to drinking water quality.

15:15

Coffee Break

15:35

Bradley B. Brogren, The Michigan Source Water Assessment Program: Surface Water Assessments to Protection Initiatives. Source Water Assessment Program, Michigan Dept. Env. Qual., Lansing, MI

The U.S. Geological Survey and the Michigan Dept. of Environmental Quality are cooperatively completing the Source Water Assessment Program (SWAP) for Michigan in compliance with the 1996 Safe Drinking Water Act. This involves defining public water supply source water areas and identifying potential avenues of contamination. Michigan has approximately 12,000 public water supplies; 69 of which use surface water intakes that serve over 50% of the state's 10 million residents. Nine of these are inland lake and river intakes, while the remaining 60 are associated with the Great Lakes and connecting channels. Source water areas for these surface water supplies are defined by watersheds, flow studies or for the upper connecting channels, a two-dimensional hydraulic flow model.

Source water assessments involve reviewing records of individual water treatment plants (intake location and construction, raw water chemistry, effects of weather, lake currents, etc), inventorying potential contaminant sources in the source water area and determining susceptibility. The assessments will be used by the state to decide appropriate monitoring programs for the water supplies, and by local municipalities to develop source water protection programs. The U.S. Environmental Protection Agency explicitly requires public consultation in developing the SWAP and public notification of source susceptibility. The increased public awareness of source-water issues should result in local initiatives that will not only protect drinking water but also contribute to improved health of the watershed.

16:00

Andrew Piggott, Groundwater, Climate, and Water Use in Southern Ontario. National Water Research Institute, Burlington, ON, Canada.

Thirty percent of the total population of Ontario, and 90 percent of the rural population, are dependent on groundwater as the source of their water supply. While groundwater-based supplies are typically economical, reliable, and of high quality, recent experience has demonstrated that even partial impairment of this source can have significant societal implications. Groundwater has an equally important role in aquatic ecosystems where the discharge of groundwater to wetlands, lakes, and rivers is a major source of stream flow and is often critical to aquatic habitat. Groundwater conditions respond to recharge during previous months and years and therefore a reduction in the infiltration of precipitation, or an increase in pumping, may compromise water supply and aquatic habitat. Recognizing the interaction of groundwater conditions, climate, and water use is very clearly an element of source water protection.

Environment Canada has conducted a multi-disciplinary study of the relation of climate and water use to groundwater conditions within the Grand River watershed in partnership with the Grand River Conservation Authority and Ontario Ministry of the Environment. The results of this study indicate that climate change may lead to reduced snow accumulation and melting and to increased evapo-transpiration, and that these factors, in conjunction with increased water use, may translate to diminished groundwater conditions. By interpreting these findings in terms of human and ecological requirements, it is possible to assess sensitivity to climate and water use and ultimately design management practices that attempt to fulfill these requirements subject to evolving land and water use. Studies that apply similar methods of analysis across the Great Lakes basin are now underway.

16:25

Panel Discussion

17:00

Adjournment