GROUNDWATER
POLLUTION POTENTIAL MAPS
Using the DRASTIC system to manage turfgrass
chemical applications at golf courses
Application of chemical fertilizers and pest control compounds for turfgrass maintenance are perhaps the greatest environmental liability facing golf courses today. Contamination of surface water, soils and groundwater have serious consequences in terms of profitability and public opinion of golf courses in general. Development of integrated management system tools to maximize benefits while reducing operating costs and potential liabilities produced by chemical applications have been gaining importance.
The impact that chemical applications will eventually produce arise from a variety of physical and cultural factors. Physical site properties affecting fertilizer/pesticide effectiveness and fate include soil texture, organic matter content, local geology, depth to ground water, topography, and climatic conditions. Often golf courses contain a variety of small-scale geologic settings that are incorporated into the course design to increase the challenge of play or enhance the aesthetic appearance of the course. Differences in topography, soil types, depth to water, and bedrock affect pollution potential from chemical applications.
DRASTIC is a systematic method for mapping and ranking the key physical properties affecting natural pollution potential for a parcel of land. DRASTIC is an acronym for the seven factors used for ranking the pollution potential. These seven factors are Depth to groundwater; aquifer Recharge; Aquifer type; Soil type; Topography; Impact of the vadose zone; and aquifer hydraulic Conductivity. Details of the system are presented in the EPA document entitled "DRASTIC: A Standardized System for Evaluating Ground Water Pollution Potential Using Hydrogeologic Settings."
The DRASTIC system produces a map that graphically illustrates the relative pollution potential of the golf course based upon the hydrogeologic settings present at the facility. An example of a DRASTIC pollution potential map is illustrated on the front page. The map is color-coded to illustrate pollution potential with warmer colors representing areas of higher pollution potential and cooler colors for areas of lesser vulnerability or pollution potential. Each hydrogeologic setting has a map symbol that conveys certain information about the parcel's physical properties. For example, the symbol 7Ac1 134 means that the parcel has glacial till over a limestone aquifer with a pollution potential rating of 134. The seven parameters and their respective ratings for this particular hydrogeologic setting is presented in the table below. A report is provided with each map describing what the various numbers and letters mean relative to their respective hydrogeologic settings.
7
AC: GLACIAL TILL OVER LIMESTONE 
The map depicts the areas on a golf course with the greatest potential for pollution by
surficial chemical applications. The areas with greatest potential require stricter
care and management to reduce potential impact to the environment. Management for
these areas may include:
-
Incorporating sensitive areas into roughs, aesthetic landscaping, or wildlife
habitats in lieu of tees, greens or fairway.
- Reducing, substituting or eliminating chemical applications in lieu of alternative types or methods of fertilization or pest control.
- Revising application formulations or methodology to reduce leaching potential for sensitive areas.
- Planting more drought or pest-resistant varieties of turfgrass in sensitive areas.
- Installing or moving chemical storage areas or underground storage tanks into areas of lesser pollution potential (if present). Alternatively, using or constructing structures of better product containment capability or release-detection capability in areas of higher pollution potential.
- Increased monitoring for highly sensitive areas;
- Modifying irrigation practices to reduce leaching potential (or reduce water-logging).
Development of a groundwater pollution potential map in the development and planning stages of golf course construction will help in building an environmentally proactive approach to managing and designing the course. The map is also an effective tool for communicating plans, methods, and efforts for providing the best, most conscientious means to environmental protection.
If you have any questions or require additional information regarding DRASTIC ground water pollution potential maps, please contact Mr. Kelly C. Smith, C.P.G. at (937) 320-3601.