University of Missouri Extension

WQ659, New October 1995

Assessing the Risk of Groundwater Contamination — Overall Farmstead Assessment

Farm•A•Syst: Farmstead Assessment System Worksheet #9

As a summary of the work you've already done to assess your farmstead structures and activities, this worksheet has two parts:

Part 1

Your first step will be to combine the individual risk rankings for various farmstead structures and activities (from Worksheets 1 through 8, MU publications WQ651 through WQ658) with your soils ranking and subsurface geologic ranking from Worksheet #8 (MU publication WQ658). Combining these rankings will give you a much more accurate picture of the groundwater contamination risk of your various farmstead practices as they are affected — for better or worse — by your particular site conditions.

Part 2

Your second step will be to list any individual farmstead activities from your 8 worksheets that you ranked with 1s (high risk). You've probably been adding to this list as you've completed each worksheet. In this part, you will be looking at individual concerns, giving you very specific information about the groundwater contamination risk of particular farmstead practices.

Getting started

Part 1

If you have not done so already, take the boxed risk rankings from the top of the scoring sheet of each of the 8 worksheets you completed and transfer them into the following box. (For the worksheets you did not complete, leave the boxes blank.)

Then take your three site-evaluation rankings from Worksheet #8 (MU publication WQ658) (soils ranking, subsurface ranking and combined ranking) and transfer them into the box below, too. (If you have fewer than three site rankings, just record the ones you have and leave the others blank.) The figures in this box are all you need to complete parts 1 and 2 of this worksheet.

Farmstead risk rankings (from Worksheets #1 to #7, MU publications WQ651 through WQ657) Site rankings (from Worksheet #8, MU publication WQ658)
#1: Well condition _____ Soils ranking #1 _____
#2: Pesticide handling _____ Soils ranking #2 _____
#3: Fertilizer handling _____ Soils ranking #3 _____
#4: Petroleum storage _____ Subsurface ranking _____
#5: Hazardous-waste management _____ Combined ranking #1 _____
#6: Household wastewater treatment ___ Combined ranking #2 _____
#7: Animal manure management _____ Combined ranking #3 _____

Step 1
To calculate overall risk rankings for each of the 8 worksheets you completed, take your farmstead risk rankings from the box, add them to the appropriate lines below and calculate the average of the two numbers.

In some cases, you will use the combined site-evaluation rank. In other cases, you will use only the subsurface ranking (for example, when you are calculating the risk associated with a septic system's soil-absorption field or an in-ground manure-storage pit).

If you don't have a combined site or subsurface rank for your farmstead, use the soil rank
Although subsurface information, either by itself or in a combined site rank, gives a more accurate picture of your site's ability to hold and break down contaminants, soil rank is an acceptable substitute for the combined site rank if subsurface information for your site is unavailable.

If you have more than one soil on your farmstead — and therefore more than one soils ranking or combined ranking to transfer — you may need to refer to your farmstead diagram in Worksheet #8 (MU publication WQ658) to see which soil is associated with each farmstead structure or practice. For each category below, use the appropriate soil ranking or combined ranking.

#1: Drinking-water well condition (MU publication WQ651)
Rank from Worksheet #1
(Do not use a site rank)
_____ = _____ Overall drinking-water well risk ranking
#2: Pesticide storage and handling (MU publication WQ652)
Rank from Worksheet #2
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall pesticide risk ranking
#3: Fertilizer storage and handling (MU publication WQ653)
Rank from Worksheet #3
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall fertilizer risk ranking
#4: Petroleum product storage (MU publication WQ654)
(Select one or both categories below, as appropriate to your site.)
Rank from Worksheet #4
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall above-ground storage risk ranking
Rank from Worksheet #4
Subsurface site rank
Total
_____
_____
_____
divided by 2 = _____ Overall below-ground storage risk ranking
#5: Hazardous waste management (MU publication WQ655)
Rank from Worksheet #5
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall hazardous waste risk ranking
#6: Household wastewater treatment (MU publication WQ656)
(Select one or both categories below, as appropriate to your site.)
Rank from Worksheet #6
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall surface household wastewater risk ranking
Rank from Worksheet #6
Subsurface site rank
Total
_____
_____
_____
divided by 2 = _____ Overall subsurface household wastewater risk ranking
#7: Livestock manure management (Select one or both categories below, as appropriate to your site.) (MU publication WQ657)
Rank from Worksheet #7
Combined site rank
Total
_____
_____
_____
divided by 2 = _____ Overall livestock manure management risk ranking

Step 2
Interpret and compare your overall risk rankings. For each ranking in the blanks above, use the box below to assess your overall groundwater-contamination risk from that area of activity on your farmstead. This information should give you a general idea of areas of concern that need addressing.

Keep in mind, however, that each of these rankings is based on an averaging of many individual activities and structures — such as all of your specific pesticide storage and handling practices in Worksheet #2 (MU publication WQ652). Don't use these overall rankings to access or predict the amount, if any, of actual groundwater contamination on your farmstead. An actual determination of groundwater contamination requires an intensive on-site investigation.

Interpreting your scores

Ranking Groundwater-contamination risk
3.6 to 4.0 Low
2.6 to 3.5 Low to Moderate
1.6 to 2.5 Moderate to High
1.0 to 1.5 High

The rankings do provide an overall assessment of the risk level of various farmstead activities and how site conditions affect these levels of risk. Part 2 focuses on specific activities or structures that you ranked as 1s on your individual worksheets.

Part 2
Identifying specific high-risk activities

Step 1
If you haven't already done so, go back to each of the worksheets you completed and identify any individual activities or structures that you ranked as 1s (high risk). You may have already done this as you completed each worksheet.

Step 2
List each activity of concern on the "High-risk activities" chart. Begin by filling in the first three blanks (to the left of the "Response options" section). Do this for each of the worksheets you completed.

Step 3
If you have completed or plan to complete the framstead diagram in Worksheet #8 (MU publication WQ658), you may use the diagram to help identify high pollution risks found using Farm•A•Syst. This diagram can assist you as you set priorities, make plans and take action to address the high-risk concerns on your farmstead.

Step 4
Then, for each activity that you listed, fill in the "response options" and "taking action" sections to the right of the double vertical line on the chart.

Planning is needed to achieve desired results. This is true not only in managing a profitable farm operation or business, but in responding to groundwater pollution risks on your farmstead as well. Some high-risk concerns will require little planning, and your initial response may take care of the problem. Other concerns will require that you develop short- and long-term strategies to respond. Use the taking action section to develop your plan of action for each high-risk concern.

Step 5
Keep this list handy and refer to it often. It provides information for you as you plan how to begin to protect the groundwater that provides drinking water to you and your family.

A few final words

After doing all you can to reduce the risk of groundwater contamination on your farmstead, you may still have well test results showing high levels of some contaminants.

You may want to keep track of potential sources of groundwater contamination beyond your farmstead. You also may want to encourage your neighbors to use this farmstead assessment.

On the other hand, despite the fact that results of your farm well water quality tests are quite good, your worksheet results may show the need for changes. Your well may be upslope from your farmstead, so the water drawn from that area is not affected by your activities. That doesn't mean, however, that contaminants are not entering the groundwater and affecting someone else's drinking water. You need to be as careful as you can about farmstead management, especially if your farmstead is on land vulnerable to groundwater contamination.

You may have quite a few "high-risk" pollution potential rankings. You also may be concerned about your well water quality test results and want to know more about how your farmstead activities might have influenced them. If so, after completing the Farmstead Assessment System, you may want to ask an expert to conduct a detailed site analysis and look more closely at potential sources to determine the causes of the contamination.

For further information about potential sources of groundwater contamination on your farmstead, contact your local MU Extension center or your Natural Resources Conservation Service office.

Table 2
High-risk activities. A listing of individual activities or structures that ranked "1" on your Farm•A•Syst worksheets

After completing each of the 7 assessments appropriate to your farmstead, list any individual activities or structures that you ranked as "1" (high risk). Fill in the worksheet number, the worksheet name and the individual activity of concern. Fill in only the first three blanks for each worksheet. You'll fill out the blanks from "Response options" and "Taking action" later.
      Response options (check one)  
Worksheet number Worksheet name Individual activity identified as being high risk (1) Immediate action possible1 Further planning required2 Taking action3
           
           
           
           
           
           

Note
Continue listing on next page as necessary.

1Change in practice only; cost not a factor;
2Requires major structural improvement or relocation; involves major effort or high cost;
3Proposed first step to address concern
The Missouri Farmstead Assessment System is a cooperative project of MU 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 Extension Service, U.S. Department of Agriculture, under special project number 91-EHUA-1-0055 and 91-EWQI-1-9271.
Adapted for Missouri from material prepared by Susan Jones, U.S. E.P.A., Region V, Water Division, and University of Wisconsin Cooperative Extension.
MU Extension Farm•A•Syst team members: Joe Lear, Regional Agricultural Engineering Specialist and Chief Editor; Beverly Maltsberger, Regional Community Development Specialist; Robert Kelly and Charles Shay, Regional Agricultural Engineering Specialists; Thomas Yonke, Program Director, Agriculture and Natural Resources; Jerry Carpenter, State Water Quality Specialist; and Bob Broz, Water Quality Associate.
Technical review provided by August Timpe, Missouri Department of Natural Resources; Charles Fulhage, MU Department of Agricultural Engineering; U.S. E.P.A. Region VII, Environmental Sciences Division; and Missouri Natural Resources Conservation Service.

 

WQ659 Assessing the Risk of Groundwater Contamination — Overall Farmstead Assessment | University of Missouri Extension

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