"Revised 10/99/3M.""Water Quality.""Farm-A-Syst : farmstead assessment system. Worksheet #1.""The Missouri Farmstead Assessment System is a cooperative project of University Outreach and Extension; College of Agriculture, Food and Natural Resources; and the Natural Resources Conservation Service. The National Farmstead Assessment Program provided support for development of the Missouri program. These materials are adapted from the Wisconsin and Minnesota prototype versions of Farm-A-Syst. This material is based upon work supported by the Cooperative State Research, Education and Extension Service, U.S. E.P.A, Region V, Water Division and University of Wisconsin Cooperative Extension. University Extension Farm-A-Syst team members: Robert Broz, Water Quality Program Director; Beverly Maltsberger, Regional Community Development Specialist; Robert Kelly, Regional Farm Management Specialist; Joe Lear, Network Support Specialist. Technical review provided by August Timpe, Missouri Department of Natural Resources; Charles Fulhage, Department of Agricultural Engineering, University of Missouri-Columbia; U.S. E.P.A. Region VII, Environmental Sciences Division; and Missouri Natural Resources Conservation Service.

University Outreach and Extension, University of Missouri

University of Missouri: MOspace

Water Quality Farmstead Assessment System Worksheet #1 Published by University Outreach and Extension, University of Missouri Assessing the Risk of Groundwater Contamination from Drinking-Water Well Condition Why should I be concerned? Approximately 95 percent of this country's rural residents use ground water to supply their drinking water and farmstead needs. Wells are designed to provide clean water. If improperly constructed or poorly maintained, they can allow bacteria, pesti­cides, fertilizer or oil products to contaminate ground water. These contaminants can put family and live­stock health at risk. " Cases exist that document well contamination from farmstead activities near drinking-water wells. The condition of your well and its proximity to con­tamffiation sources determine the risk it poses to the water you drink. For example, a cracked well casing allows bacteria, nitrates, oil and pesticides to enter the well more easily. Spilling pesticides being mixed and loaded near the well could result in the contami­nation of your family's drinking-water supply. Feedlots, animal lots, septic systems, fertilizer appli­cations and waste storage areas could release large amounts of nitrate, contaminating your well. Preventing well-water contamination is impor­tant. Once the ground water supplying your well is contaminated, it is difficult to clean up. The only options may be to treat the water, drill a new well or get water from another source. A contaminated well also can affect your neighbors' wells, posing a serious health threat to your family and neighbors. The goal of Farm·A·Syst is to help you protect the ground water that supplies your drinking water. How will this worksheet help me protect my drinking water? • It will take you step by step through your drinking­water well condition and management practices. •	 It will rank your activities according to how they might affect the ground water that provides your drinking-water supplies. •	 It will provide you with easy-to-understand rank­ings that will help you analyze the "risk level" of your drinking-water well condition and manage­ment practices. •	 It will help you determine which of your practices are reasonably safe and effective and which prac­tices might reqUire modification to better protect your drinking water. How do I complete the worksheet? Follow the directions at the top of the chart on the next page. It should take you about 15 minutes to 30 minutes to complete this worksheet and determine your ranking. Focus on the well that provides drinking water for your home or farm. If you have more than one drinking-water well on your farmstead, fill out a worksheet for each one. WQ 651 work sheet Printed with soy ink on recycled paper Archive versin -- See extnsion.missuri.eduDrinking-Water Well Condition: Assessing Drinking-Water Contamination Risk 1.	 Use a pencil. You may want to make changes. 3. Then look above the descriphon you circled to find your "rank number" 2.	 For each category listed on the left that is appropriate to your farmstead, (4,3,2 or 1) and enter that number in the blank under "your rank." read across to the right and circle the statement that best describes condi­ 4. Directions on overall scoring appear at the end of the worksheet. tions on your farmstead. (Skip and leave blank any categones that don't 5. Allow about 15 nunutes to 30 minutes to complete the worksheet and apply to your fannstead.) figure out your risk ranking for well-management practices. LOW RISK LOW-MOD RISK MOD-HIGH RISK HIGH RISK YOUR (rank 4) (rank 3) (rank 2) (rank 1) RANK LOCATION PosHion of drinking-water well in relation to pollution SOurces Upslope from all pollu­nan sources. No surface-water runoff reaches well. Surface water diverted from well. Upslope from or at grade with pollution sources. No surface-water runoff reaches well. Downslope from most poilu tion sources. Some surface-water runoff may reach well. Settling or depression near casmg. Surface-water runoff from live­stock yard, pesticide and fertilizer mixing area, fuel storage or farm dump read>es weU. Separation distances between well and farmstead contamina­tion sources' Meets or exceeds all slate minimum-separa­tion distances. Meets most minimum-separation distances. Meets minimum-sepa­ration distances only for sources required to be at least 100 feel from well." Does not meet all minimum separation dis tances for sources req uired to be at least 100 feet from well. Soil and/or·subsurface po tential to protect ground water CONDITION Fine-textured soils (clay loams, silty clay). Water table or frac­tured bedrock deeper than 20 feet. Medium-textured soils (silt loam, loam). Water table or frac­hlTed bedrock deeper than 20 feet. Medi um- or coarse-tex­tured soils. Water table Or fractured bedrock deeper than 20 feet. Coarse-textured soils (sands, sandy loam). Water table or frac­lured bedrock shallow­er than 20 feel. Condition of casing and well cap (seal) No holes or cracks. Cap tightly secured. Screened ven t. Casing properly grouted. No defects visible. Well vented but not screened. No holes or cracks visible. Cap loose. Holes or cracks VIsible. Cap loose or missing. Can hear wa ter running. C~sing depth Cased more than 30 feet below water level in your well. Cased 15 feet to 30 feet below water level in your well. Cased less than 15 feet below bedrock in your well. No casing. Casing height above land surface More than 12 inches above grade. 8 inches to 12 inches above grade. At grade or up to 2 inches to 8 inches above. 2 ind>es or below grade or in pit or basement. Well age Less than 20 years. 21 years to 50 years. 51 years to 70 years. More than 70 years. Well type Drilled Driven-poinl (sand point) Dug well MANAGEMENT Backflow prevention Anti-backflow devices (such as check valves) installed on all faucets with hose connections. No cross-connections between water sup­plies. Anti-backflow devices installed On some faucets with hose connections. No anti-backflow devices. Air gap maintained. No anti-bac.kflow devices. Air gap not maintained. Cross-connections between water supplies. Unused well No unused, unsealed wells. Unused wells capped and protected. Unused, unsealed well in field. Not capped or protected. Unused. unsealed well in farmstead. Not capped or protected. Water testing Consistent satisfactory water quality. Bacteria, nitrate and other tests meet standards. Occasional deviation from standards with bacteria, nitrate and other tests. Bacteria, nitrate and other lests mostly do not meet standards. No water tests done. Water discolored after rainstorms or during spring melt. Noticeable changes in color, clarity, odor or taste. Bold'ace type: BeSIdes representing a higher-nsk choice, this practice also violates Us;. thi$ rOTAL to calculnte risk ranking Mlssourllaw. ott page 3 of worksheet 'See page 2 01 Fact Sheet #1. Improving D,{nkmg-Wnler Well CondillOIl. ""-Should be a. mimmum distance 150 teet for fertilizer and chemical storage. Page 2	 WQ 651 work sheet planning and prioritizing before you take action. What do I do with these Find any activities that you identified as Is and list them under "High-Risk Activities" in Worksheetrankings? #9. Step 1: Step 3: Begin by determining your overall well manage­ment risk ranking. Total the rankings for the cate­gories you completed, and divide by the number of categories you ranked: __ divided by __ equals Dtotal of # oI categories ran.kU1gs r.nked nsk ranking" "'Carry your answer out 10 one deClmal place. • 3.6 - 4 == low risk • 2.6 - 3.5 =low to moderate risk • 1.6 - 2.5 == moderate to high risk • 1 - 1.5 == high risk This ranking gives you an idea of how your well management practices as a whole might be affecting your drinking water. This ranking should serve only as a general guide, not a precise diagnosis. Because it represents an average of many individual rankings, it can mask any individual rankings (such as Is or 2s) that should be of concern. (See Step 2.) Enter your boxed well management risk ranking on page 1 of Worksheet #9. Later you will compare th}s risk ranking with other farmstead management rankings. Worksheet #8 will help you identify your farmstead's site conditions (soil type, soil depth and bedrock characteristics) and Worksheet #9 will show you how these site conditions affect your risk rank­ings. Step 2: Look over your rankings for individual activities: • Low-risk practices (4s): ideal; should be your goal despite cost and effort. •	 Low- to moderate-risk practices (3s); provide rea­sonable ground-water protection. •	 Moderate- to high-risk practices (2s); inadequate protection in many circumstances. •	 High-risk practices (Is); inadequate; pose a high risk of polluting ground water. Regardless of your overall risk ranking, any indi­vidual rankings of "1 fI require immediate attention. Some concerns you can take care of right away; oth­ers could be major - or costly - projects, requiring Read Fact Sheet #1, Improving Drinking Water Well Condition, and consider how you might modify your farmstead practices to better protect your drinking water. Glossary These terms may help you make more accurate assessments when completing Worksheet #1. They may also help clarify some of the terms used in Fact Sheet #1. Abandoned water well: A permanently discontinued well or a well that is in such disrepair that its con­tinued use for the purposes of obtaining ground water is impractical or may be a health hazard. Air gap: An air space (open space) between the hose or faucet and water level, representing one way to prevent backflow of liquids into a well or water supply. Anti-backflow (anti-backsiphoning) device: A check valve or other mechanical device to prevent unwanted reverse flow of liquids back down a water-supply pipe into a well. AqUifer: A water-bearing formation (soil or rock horizon) that transmits water in sufficient quanti­ties to supply a water well. Bored wells: Wells constructed using augers, scoops, drag lines or similar equipment. These holes are usually of large diameter and are constructed in alluvial or glacial material. Casing: An impervious durable pipe placed in a well to prevent the walls from caving and to keep out surface drainage or undesirable water, gas or other fluids. Cross-connection: A link or channel between pipes, wells, fixtures or tanks carrying contaminated water and those carrying 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 are normally 4 inches to 8 inches in diameter. Driven-point (sand-point) wells: Wells constructed by driving assembled lengths of pipe into the ground with percussion equipment or by hand. These wells are usually smaller in diameter (2 inches or less), less than 50 feet deep and can be installed in areas of relatively loose soils, such as WQ 651 work sheet	 Page 3 sand. Dug wells: A well in which the side walls may be supported by material other than standard weight steel casing. Water enters a dug well through the sides and bottom. Ground water: The water in the zone of saturation in which all of the pore spaces of the subsurface material are filled with water. The water that sup­plies springs and wells is ground water. Grout: Slurry of cement or bentonite clay used to seal the annular space between the outside of the well casing and the bore hole. Also used in sealing abandoned wells. Milligrams per liter (mg!l): The weight of a sub­stance measured in milligrams contained in 11iter. It is equivalent to 1 part per million in water mea­sure. Parts per million (ppm): A measurement of concen­tration of one unit of material dispersed in 1 mil­lion units of another. Pressure grout: Refers to the process of applying grout material under pressure to the annular space of a well for the purpose of sealing it and thus pre­venting vertical movement of fluids through the annular space. Grout must be introduced from the bottom of the annular space. 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 (seal): A method or device used to protect a well casing or water system from the entrance of any external pollutant at the point of entrance into the casing. The Missouri Farmstead Assessment System is a cooperative project of FARM.A .SYST University Outreach and Extension; College of Agriculture, Food and Natural Resources; and the Natural Resources Conservation Service. Farmstead Assessment System The National Farmstead Assessment Program provided support for development of the Missouri program. These materials are adapted from the Wisconsin and Minnesota prototype versions of Farm-A-Syst. This material is based upon work supported by the Cooperative State Research, Education and Extension Service, U.S. E.P.A, Region V, Water Division and University of Wisconsin Cooperative Extension. University Extension Farm-A-Syst team members: Robert Broz, Water Quality Program Director; Beverly Maltsberger, Regional Community Development Specialist; Robert Kelly, Regional Farm Management Specialist; Joe Lear, Network Support Specialist. Technical review provided by August Timpe, Missouri Department of Natural Resources; Charles Fulhage, Department of Agricultural Engineering, University of Missouri-Columbia; U.S. E.P.A. Region VII, Environmental Sciences Division; and Missouri Natural Resources Conservation Service. This publication is available from your University Extension centers or from Extension Publications, University of Missouri, 2800 Maguire Blvd., Columbia, MO 65211, phone 1-800-292-0969. 19 • Issued In furtherance 01 Cooperallve Exfenslon Work Acls of May B end June 30, 1914. In cooperetlon With the United States OUTREACH & EXTENSION Department of Agflcullure Ronald J Turner, D"ector, Cooperallve ExtenSion, UniverSity 01 Missouri and lincoln UniverSity. Columb,a, MO 65211 • University Outreach and ExtenSion does not discriminate on the baSIS 01 race, color, national ongln, sex, religion, age, disability COLUMBIA	 Or status as a Vietnam era veleran In employment or programs • II you have special needs as addressed by Ihe Americans With Disabilities Act and need thiS publicatIon ,n an alternative lormat, write ADA Officer, ExtenSIon and Agricultural Inlormatlon, 1-98 Agriculture BUilding. COlumbia, MO 65211, or call (573) 8B2·7216 Reasonable afforts will be made 10 accommodate your spacial needs UNIVIRSITY O' MISSOURI Page 4	 WQ 651 work sheet Revised 1O/99/3M 

Assessing the risk of groundwater contamination from : drinking-water well condition (1999)

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