USING A GROUNDWATER DATABASE WITH COMPUTER MAPPING

Ingham County is located in lower central Michigan and contains the state capital, Lansing, Michigan State University and General Motors Corporation. Ingham County has a total population of 279,320 with 42,382 living in the rural areas of the county. The residents of Ingham county obtain 100% of their drinking water from groundwater resources. Approximately 17 percent of Ingham county residents obtain their water from private water supply wells and the other 83 percent from a municipal water system. Ingham County residents have one of the largest known fresh groundwater sources in the state which is the Saginaw bedrock aquifer, containing approximately 4 cubic miles of water under Ingham County. Approximately 95 percent of the population obtain their water from the Saginaw aquifer by wells between 150 and 450 feet deep. The remaining 5 percent obtain water from more shallow glacial deposit type water wells.

In 1981 the Ingham County health Department recognized the need to establish programs that would effectively protect the groundwater resources. Several threats to both groundwater and surface water resources were considered which included chemical storage and spills, landfills, gasoline stations, old underground storage tanks, use of agricultural chemicals, road salt, petroleum fuel lines, surface water runoff, soil erosion, and sedimentation. To implement an effective protection program is was determined that a survey of both the county geology and water chemistry was needed. Computers were used for a well construction/lithology and a water chemistry database. These databases are used in conjunction with other software programs including mapping or GIS software, to help evaluate and analyze the geologic and water chemistry data. Data was collected from a variety of existing public and private water wells throughout the county to develop the databases. Each well in the database was sampled for 33 inorganic parameters which included the major cations and anions. Several wells were also tested for organic chemicals such as solvents or pesticides depending on the site use and concern. This extensive program to collect water samples from wells and match them with well construction records has now been an on-going project since 1981.

This project was not possible without the assistance of several state and local government agencies, academic institutions and a few private consultants. Assistance came in the form of education, consultation, monetary and direct personnel service. The groups that provided this assistance included Michigan State University, Michigan Department of Environmental Quality, Western Michigan University, Michigan Department of Agriculture, U.S. Geological Survey , U.S. Natural Resources Conservation Service, Tri-County Regional Planning Commission and Password computer consultants. Assistance also came from membership with The Southwest Michigan Groundwater Survey and Monitoring Program. By combining resources with other interested counties it became possible to share ideas and approach other agencies for help which also provided the tools to develop the groundwater database.

The county= s current groundwater database includes 11,068 water well records and 1,859 complete water chemistry records in addition to the location of known and suspected groundwater pollution sites. The county also has additional computer generated maps of groundwater flow direction, water chemistry trends, geologic analysis of the bedrock and glacial drift aquifers, site locations of septic tank waste and municipal waste application, soils maps and underground storage tanks.

The groundwater database provides the tools to help us inform and educate the public about the water they drink, provide the information needed to help direct land use planning projects and issue permits for water

supply wells. Geologic cross-sections from well records help determine physical characteristics of land and geology to evaluate proposed developments. A database of soil types is used to predict the potential for on-site wastewater treatment systems. Using the water chemistry database in conjunction with several software programs makes it possible to evaluate an individual water supply and determine the possibility of a pollution concern.

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One example of this work includes a site review for a proposed subdivision. A residential subdivision was proposed near a closed township landfill site. Data from existing wells allowed our office to examine lithology, water chemistry and groundwater flow direction. It was determined that groundwater flow from the landfill did move towards the proposed subdivision. Water chemistry provided information that current groundwater near the proposed landfill was unaffected and would also be used as a baseline for water quality conditions. Lithology data and geologic cross-sections indicated that water wells could also be constructed with casing depths into a deep shale bedrock to provide extra protection for new water wells.

A case study for looking at a specific chemical parameter over the entire county involved using sodium and boron levels in water wells. At the time the county= s groundwater database was being established there was a growing interest from the medical community on boron in the human diet. Boron appears to help reduce osteoporosis in woman. Since boron was tested for in the survey, our colleagues at Western Michigan University asked us to use our GIS mapping tools to review boron levels in the county. A distinct pattern was found which showed that naturally softened water wells (high sodium levels in the water), in the NE quadrant of the county were also high in boron levels, (levels gt 1.00 ppm). Most water in Ingham County is hard water (gt 200.0 ppm hardness as calcium carbonate), but wells in this area appear to be softened by the greater amount of shale bedrock in the boreholes as determined by the well lithology database. This was also a concern since the EPA has issued a health advisory for boron and has proposed a standard of 0.90 ppm for drinking water. These levels of boron were made by the EPA because of the negative effects to the male reproductive system. Boron is also a concern for farmers and greenhouse managers since many plants have a very narrow range for required boron levels and those that are toxic to plants.

Several recommendations were made to examine the role of boron in drinking water. This included a survey of woman for osteoporosis in the areas where woman may have been using this water for an extended part of their lives. It was also recommended that wells which tested for naturally soft water also be checked for boron. This recommendation was also made for individuals involved with plant and crop production and using irrigation water.

Currently Ingham County has moved its water well construction record database to a Statewide Internet type program called WELLOGIC. This statewide program allows anyone to access records from anywhere in the state. Our next project is to move the water chemistry data to a similar statewide water chemistry database.

References and other reading:

1. A Report on the Aquifers of Ingham County@ (1988), Lansing Mich: Ingham County Health Dept.

2. Center for Remote Sensing (1989), C-Map Computer Mapping, Ver. 1.03, E. Lansing, Mich. State Univ.

3. Office of Water (1996), A Boron Drinking Water Health Advisory,@ Drinking Water Regulations and Health Advisories, EPA 822-R-96-001, Washington D.C. : U.S. Environmental Protection Agency.

4. Rowe, G.W., (Dec. 1999), A Surveying Boron and Naturally Soft Groundwater with a Computer Database,@ Journal of Environmental Health, Vol. 62, No. 5: 14-18.

5. Rowe, G.W. and Dulaney, S.J., (1991) Building and Using a Groundwater Database, Lewis Publishers, Chelsea, Michigan.

6. Michigan Department of Environmental Quality, Drinking Water and Radiological Protection Division, A WELLOGIC@ software, Lansing, Michigan, Email: DEQ-DWR-Wellogic@Michigan.gov.

7. SURFER, version 7.0, (1999), Golden Software, Inc., Golden, Colorado, www.goldensoftware.com.

8. STATGRAPHICS PLUS,version 3.0, (1997), Manugistics, Inc., Rockville, Maryland, 20852.

9. ArcMAP 8, (2000), ESRI, New York Street, Redlands, CA 92373-8100, www.esri.com.