DRINKING WATER SOURCE ASSESSMENT for Myeerah Nature Center (PWS ID # OH4652616)
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DRINKING WATER SOURCE ASSESSMENT for Myeerah Nature Center (PWS ID # OH4652616) September 17, 2014 INTRODUCTION. The 1996 Amendments to the Ground Water Pollution Potential for Logan Safe Drinking Water Act establish a program for County (ODNR, 1995), depth to water in this states to assess the drinking water source for all aquifer is between 75 to 100 feet below the public water systems. Ohio’s Source Water ground surface. Assessment and Protection Program is designed to help public water systems protect their sources Soils in the area are silty loam (the upper 7 inches of drinking water from becoming contaminated. of soil) and silty clay (beneath the silty loam and This assessment: within 5 feet below ground surface). The soils have a low permeability, meaning that much of the identifies the drinking water source protection rainfall and snowmelt has a tendency to run off area, based on the area that supplies water to the surface then to infiltrate the surface. the well(s); The topography immediately surrounding the well inventories the potential contaminant sources is generally flat with an average relief of 6 to 12 in the area; feet over a distance of 100 feet. Ground water in this area is replenished by the gradual flow of evaluates the susceptibility of the drinking water underground from higher to lower elevations water source to contamination; and and by approximately 4 to 7 inches per year of precipitation that infiltrates through the soil. In recommends protective strategies. karst settings, local flow direction is highly variable and is influenced by fracture orientation. Since The purpose of the assessment is to provide detailed information on local fracture orientation is information that Myeerah Nature Center can use unavailable, flow direction cannot be accurately to help protect its source of drinking water from determined. contamination. PROTECTION AREA. The protection area for SYSTEM DESCRIPTION & GEOLOGY. Myeerah Myeerah Nature Center was delineated on Nature Center is a non-community public water September 15, 2014 and is depicted in Figure 2. system serving 25 people in Jefferson Township, Figure 2 shows two areas, one inside the other. Ohio. This system operates 1 well that pumps The “inner protection zone” is located closer to the approximately 2,000 gallons of water per day. water supply well and a chemical spill in this zone There is no well log for the system, but based on poses a greater threat to the drinking water, so surrounding well log information, the drinking this area warrants more stringent protection. The water is likely obtained from a carbonate bedrock “outer protection zone” is the additional area that aquifer (water-rich zone) that is located in a contributes water to pumped wells within five potential karst region. Ohio’s potential karst years. Together, the zones comprise the drinking regions are carbonate aquifers that are covered water source protection area. by less than 25 feet of glacial material and typically exhibit surficial karst features, such as Method Selection sinkholes. A map of the potential karst regions in A variety of methods can be used to determine a Southwest Ohio is presented in Figure 1. Based public water system’s drinking water source on review of available resources, it appears that protection area, from simple equations to more the aquifer is covered by less than 25 feet of low- complex computer modeling programs. In karst permeability material, which provides minimal areas, the use of modeling programs to determine protection from contamination. Based on the protection areas is inappropriate because modeling programs assume that water is flowing drinking water source protection area was slowly through grains of silt and sand. Also, conducted by Ohio EPA with the assistance of modeling programs require a good understanding Myeerah Nature Center personnel (Figure 2). of the ground water flow direction to produce an accurate protection area. In karst areas, water A facility or activity is listed as a potential can flow quickly through discrete fractures in solid contaminant source if it has the potential to rock and the ground water flow direction is often release a contaminant, based on the kinds and variable. For these reasons, Ohio EPA conducted amounts of chemicals typically associated with dye trace investigations in Ohio’s karst aquifers to that type of facility or activity. It is beyond the better understand how quickly water can travel in scope of this assessment to determine whether Ohio karst areas and define more appropriate any specific potential source is actually releasing protection areas in karst aquifers. Data from dye (or has released) a contaminant to ground water. traces indicate that ground water flow velocity in Also, the inventory is limited to what our staff was karst aquifers can be up to 22,800 feet per day. able to observe on the day of the site visit. Therefore, Myeerah Nature Center staff should be Since dye trace data indicate ground water flow alert to the possible presence of potential sources rates are fast in karst aquifers, a regional of contamination that are not on this list. delineation was performed for Myeerah Nature Center. As a starting point, the volumetric GROUND WATER QUALITY. A review of equation was used to delineate a calculated fixed Myeerah Nature Center’s water quality record radius based on a maximum pump rate of 2,000 currently available in Ohio EPA’s drinking water gallons per day pump, 10 feet aquifer thickness, compliance database did not reveal any evidence and 3% porosity. This circular area represents of chemical contamination at levels of concern in the public water systems inner management zone. the aquifer. To determine the outer management zone, the circular area was extended up-gradient until it Please note that this water quality evaluation has reached a ground water flow divide. some limitations: In addition, the protection area was expanded 1) The data evaluated is for treated water samples laterally to account for uncertainty in ground water only, as Ohio EPA’s quality requirements are flow direction and the contribution from fractures for the water being provided to the public, not that differ in orientation from the primary flow the water before treatment. direction. 2) Sampling results for coliform bacteria and Finally, since there are multiple wells in this karst naturally-occurring inorganics (other than area, a regional composite protection area was arsenic) were not evaluated for this delineated. The Zane Shawnee Caverns public assessment, because they are not a reliable water system shares some of your protection indicator of aquifer contamination. area. SUSCEPTIBILITY ANALYSIS. This assessment If you would like to have more information about indicates that Myeerah Nature Center’s source of how this protection area was derived, or if you drinking water has a high susceptibility to would like to collect additional information and contamination because: revise your protection area, please call Ohio EPA staff listed at the end of this report. Also, a more The well is located in a sensitive potential karst detailed discussion of the technical aspects of area. modeling drinking water source protection areas can be found in the Delineation Guidelines and This does not mean that the aquifer will become Process Manual (Ohio EPA, 2009) on Ohio EPA’s contaminated, only that under the existing Source Water Assessment and Protection Web conditions ground water could become impacted page http://epa.ohio.gov/ddagw/swap.aspx. by potential contaminant sources. INVENTORY. On June 17, 2014, an inventory of PROTECTIVE STRATEGIES. Each public water potential contaminant sources located within the supplier can take a few simple steps to protect the 2 drinking water source. The attached checklist For further technical assistance on drinking water identifies strategies for protecting your drinking source protection, please contact the Ohio EPA water source from the potential contaminant Southwest District Office at (937) 285-6357, or sources located on your property. Ohio EPA visit the Ohio EPA Source Water Assessment and encourages Myeerah Nature Center to please Protection Web page at: take a few minutes to review this checklist, then: www.epa.ohio.gov/ddagw/swap.aspx. Place a checkmark in the box next to the This report was written by Megan Marhelski, Ohio protective strategies that could be implemented EPA, Division of Drinking and Ground Waters, at your facility, and indicate the date you plan Southwest District Office. to implement the strategy. BIBLIOGRAPHY If a protective strategy included in the checklist Ohio EPA public drinking water files. is not appropriate or applicable to the facility, please mark N/A next to the strategy. Ohio Department of Natural Resources, 1995, Ground Water Pollution Potential of Logan If a strategy is already in place, check the box County, Ohio, Report No. 36 and indicate, in the date column, approximately when the strategy was implemented. Ohio Department of Natural Resources, 2000, Glacial Aquifer Map (digital). Please note the protective strategies in this checklist are recommended best management Ohio EPA, 2009, Drinking Water Source practices for the potential contaminant sources Protection Area Delineation Guidelines & Process identified during your inventory and are not a Manual. comprehensive list of the strategies that can be used to minimize the potential for contamination. United States Department of Agriculture, 2013, Local ordinances and state and federal Web Soil Survey, Logan County, Version 11, regulations may also apply to the potential accessed on September 16, 2014 contaminant sources that appear in this checklist. (http://websoilsurvey.nrcs.usda.gov/app/WebSoilS Ohio EPA recommends that you become familiar urvey.aspx) with the requirements of any ordinances and regulations that may apply. Ohio EPA can also provide assistance with education and training activities. Myeerah Nature Center’s shares its drinking water source protection area with Zane Shawnee Caverns.