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Utah Farm•A•Syst Worksheet #1 Page 1Assessing the Risk of Ground WaterContamination fromDrinking Water Well ConditionUtah Farm •A•Syst Worksheet #1 November 1999Why should I be concerned?Nearly 100 percent of Utah’s rural residents use ground water (wells and springs) to supply theirdrinking water and farmstead needs. Wells are designed to provide clean water. If improperlyconstructed and maintained, however, they can allow oil, fuel, fertilizer, pesticides, bacteria and othercontaminants to pollute ground water. These contaminants can put family and livestock health at risk.There are documented cases of well contamination from farmstead activities near drinking water wells.The condition of your well along with its location in relation to sources of contamination determine therisk it poses to the water you drink. For example, a cracked well casing allows bacteria, nitrates, oil andpesticides to enter the well more easily. A spill of pesticides being mixed and loaded near the wellcould result in the contamination of your family’s drinking water supply. Feedlots, animal yards, septicsystems, fertilizer storage, and waste storage areas could release large amounts of nitrate which maycontaminate your well.Preventing well water contamination is very important. Once the ground water supplying your wells iscontaminated, it is very difficult to clean up. The only options may be to treat the water, drill a new well,or obtain water from another source. A contaminated well can also affect your neighbors’ wells, posinga serious health threat to others.The goal of Farm •A•Syst is to help you protect the ground water that supplies your drinkingwater.How will this worksheet help me protect my drinking water?• It will take you step by step through your drinking water well condition and management practices.• It will rank your activities according to how they might affect the ground water that provides yourdrinking water supplies.• It will provide you with easy-to-understand rankings that will help you estimate the risk posed by yourdrinking water well condition and management practices.• It will help you determine which of your practices are reasonably safe and effective, and whichpractices might require modification to better protect your drinking water.Information derived from Farm•A•Syst worksheets is intended only to provide general information and recommendations to farmers regardingtheir own farmstead practices. It is not the intend of this educational program to keep records of individual results.UTAH STATE UNIVERSITY EXTENSION • UTAH DEPARTMENT OF AGRICULTURE AND FOOD • UTAH DEPARTMENT OFENVIRONMENTAL QUALITY • UTAH FARM BUREAU • UTAH ASSOCIATION OF CONSERVATION DISTRICTS • NATURAL RESOURCESCONSERVATION SERVICEFARM •A• SYSTFarmstead Assessment SystemUtah Farm•A•Syst Worksheet #1 Page 2How do I complete the worksheet?Follow the directions at the top of the chart on the next page. It should take you about 12-20 minutes tocomplete this worksheet and determine your ranking. If you have more than one drinking water well, fillout a worksheet for each one.GlossaryDrinking Water Well ConditionThese terms may help you make more accurate assessments when completing Worksheet #1. They may also help clarify some ofthe terms used in Fact Sheet #1.Abandoned well: A well that has been permanently taken out of use. To be permanently abandoned, a well must besealed according to Utah State Engineer’s rules.Air gap: An air space (open space) between the hose or faucet and water level, representing one way to preventbackflow of liquids into a well or water supply.Anti-backflow (anti-backsiphoning) device: A check valve or other mechanical device to prevent unwanted reverseflow of liquids back down a water supply pipe into a well.Aquifer: An underground layer or geologic formation in which ground water saturates the pores between the rocks orsoil particles.Backflow: The unwanted reverse flow of liquids in a piping system.Backsiphonage: Backflow caused by formation of a vacuum in a water supply pipe.Casing: Steel or plastic pipe installed while drilling a well, to prevent collapse of the well bore hole and entrance ofcontaminants, and to allow placement of a pump or pumping equipment.Cross-connection: A link or channel between pipes, wells, fixtures or tanks carrying contaminated water and thosecarrying potable (safe for drinking) water. Contaminated water, if at higher pressure, enters the potable water system.Drilled wells: Wells not dug or driven, including those constructed by a combination of jetting or driving. These wells arenormally 4 to 8 inches in diameter.Dug wells: Large-diameter wells often constructed by hand.Grout: Slurry of cement or clay used to seal the space between the outside of the well casing and the bore hole, or toseal an abandoned well.Milligrams per liter (mg/l): The weight of a substance measured in milligrams contained in 1 liter. It is equivalent to 1part per million in water measure.Parts per million (ppm): A measurement of concentration of one unit of material dispersed in one million units ofanother.Unused well: A well which is currently not in use, but may be used in the future.Water table: The upper level of ground water in a zone of saturation. Fluctuates with climatic conditions on land surface,and with aquifer discharge and recharge rates.Well-cap: A device used to cover the top of a well casing pipe.Utah Farm•A•Syst Worksheet #1 Page 3Utah Farm•A•Syst Worksheet #1Drinking Water Well Condition: Assessing Drinking WaterContamination Risk1. Use a pencil. You may want to make changes.2. For each category listed on the left that is appropriate to your farmstead, read across to the right and circle the statement that bestdescribes conditions on your farmstead. (Skip and leave blank any categories that don’t apply to your farmstead.)3. Then look above the description you circles to find your “rank number: (4, 3, 2 or 1) and enter that number in the blank under “yourrank.”4. Directions on overall scoring appear at the end of the worksheet.5. Allow about 15-30 minutes to complete the worksheet and figure out your risk ranking for well management practices.LOW RISK(rank 4)LOW-MOD RISK(rank 3)MOD-HIGH RISK(rank 2)HIGH RISK(rank 1)YOURRANKLOCATIONSlope of landnear drinkingwater well.Well positionin relation topollutionsources.Well is upslopefrom all pollutionsources. Allsurface waterrunoff is divertedso that it drainsaway from thewell.Well is at gradewith pollutionsources, but surfacewater runoff doesnot drain frompollution sources.No water standsnear the well afterprecipitation.Well is downslopefrom a pollutionsource. Surfacewater runoff is notdiverted and mayreach the well.Settling or depres-sion near casing.Well is locateddownslope frommore than onepollution source.Surface waterrunoff stands nearwell._____Separationdistancesbetweenfarmsteadpollutionsources anddrinking waterwell.All legal separationdistances are med(cesspools,drainfields, sewerlines, septic tanks).Other sources are100 feet (more athigh risk sites).Legal separationdistances are met,but are inadequatedue to other factors(well is usedheavily, coarse soil,shallow groundwater, etc.).One or moresources closerthan legally re-quired separationdistance.* Othersources not cover-ed by law are lessthan 100 feet fromwell._____Position ofdrinking waterwell related toflooding.Well is outside of aflood plain. Noflood water everreaches well.Well is inside floodplain at an elevationabove highest floodlevel on record.Water has notreached well.Well is inside floodplain at an elevationbelow highest floodlevel on record.Flood water mayreach well.Well is locatedinside flood plainand near stream.Flood water standsaround well casingsome years._____WELL CONSTRUCTION**Well Age Less than 20 yearssince construction.20 to 50 years sinceconstruction.50 to 70 years sinceconstruction.Over 70 yearssince construction._____Casing heightabove landsurface orhighest floodlevel.18 inches or moreabove grade or 3feet above thehighest recordedflood level.18 inches abovegrade, but less than3 feet above thehighest flood level.Less than 18 inchesabove grade or thehighest recordedflood level.At or below gradeor highest floodlevel. In a pit or ina basement. Morethan 70 years old._____LOW RISK(rank 4)LOW-MOD RISK(rank 3)MOD-HIGH RISK(rank 2)HIGH RISK(rank 1)YOURRANKUtah Farm•A•Syst Worksheet #1 Page 4Well type. Well drilledaccording to UtahCodes.Driven well or sandpoint.Drilled wellconstructed byunlicensed driller.Dug well._____Well seal. Steel casing ingood condition issealed with 3inches totalgrouting to at least18 feet deep. Wellis securely capped.Extent of grouting isunknown. Well capis loose. Conditionof casing is un-known. Plasticcasing within 18feet of surface.Casing is uncap-ped, corroded,punctured, cracked,or grouting is loose(casing moves byhand). Less than 3inches grouting._____Casing depthand depth ofscreenedintake.Approved solidcasing is installedto bottom of borehole (at least 18feet). Screenedintake.Casing does notreach water table oraquifer. Casing isperforated abovewater table (waterdrips into well).No casing (orlining in dugwells). Screenedintake is less than18 feet below thesurface._____Backflowprevention.Anti-backflowdevices on allfaucets with hoseconnections. Noplumbing connec-tions like drinkingwater and otherwater supplies.Anti-backflowdevices not on allfaucets with hoseconnections, but airgap is maintained.No plumbing cross-connections exist.Drinking water andother water supplieshave plumbingcross-connections.Air gap may bemaintained. No anti-backflow devices.No anti-backflowdevices areinstalled. An airgap is notmaintained.Plumbing cross-connections linkwater supplies_____WELL MANAGEMENTUnused wells. No unused,unsealed wells arein or nearfarmstead.All unused wells arecapped andprotected.An unused,unsealed well is inor near thefarmstead.Unsealed well infarmstead in sameaquifer as drinkingwater well._____Water Testing. Consistentsatisfactory waterquality. All testsmeet standards.Last tests weresatisfactory, but aremore than 1 yearold.Water has not beentested.Water tests do notmeed standards. Achange in odor,taste, clarity, orcolor occurs._____Welldisinfection.Well is disinfectedas bacteria testsindicate.Well is disinfectedannually.Well has never beendisinfected.High bacteriacounts, but notdisinfected._____TOTAL SCORE           _____This worksheet is designed for assessing water table wells. Some categories are inappropriate for artesian walls. See Fact Sheet #1 for moreinformation.Boldface type: Besides representing a higher-risk choice, this practice also violates Utah law.* Illegal for new well construction. Existing wells must meet separation requirements in effect at time of construction. See Fact Sheet #1 forseparation distances.**Contact the Utah Division of Water Rights for copies of water well logs which should provide information about these factors associated with wellconstruction.

Assessing the Risk of Surface and Ground Water Contamination From Drinking Water Well Condition

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Assessing the Risk of Surface and Ground Water Contamination From Drinking Water Well Condition

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