Small Acreage Factsheet # 18
Before You Buy:
Wells, Septic Systems, and a Healthy Homesite

To Buy or Not to Buy

The ideal country home provides fresh air, productive soils, and clean water. Many people look for homes based on location, view, and house style. Rural home seekers must do more. In the absence of city utilities, buyers must choose a property that can provide the basic needs: drinking water, sewage treatment, and other considerations.

Soil Survey Savvy

A soil survey is a good place to start in choosing the right property. You can use a soil survey to find out whether land has the right soils for house foundations, septic systems, crops, or wildlife ponds. Soil surveys are only accurate to a 5-acre area, so it’s important to get a professional to conduct an on-site investigation for building and septic system suitability.

You can do a preliminary investigation, just by looking at soil color. Dig a hole and look at each soil layer. Bright brown, red, and yellow colors indicate well-drained soils that may be suitable for septic systems or building sites. Gray soils or gray soils with mottled "rust spots" indicate poorly drained soils that may be good for ponds. Gray or mottled soils may be dry during the summer, but are often saturated during the winter. Vegetation may also indicate soil drainage.

Assessing Steep Slopes

A soil survey has information on land slope and its suitability for buildings and septic systems. Avoid building on steep slopes. Building and placing fill at the top of a slope, making road cuts, removing vegetation, and changing water drainage may cause erosion or landslides on steep slopes. If you see "J-shaped" trunks on trees on a site, beware. This indicates that trees are slowly adjusting to a slumping slope. Look elsewhere for a stable home site.

Floodplains and Wetlands

Floodplains provide "relief valves" that reduce flood damage. Wetlands filter pollutants, provide wildlife habitat, and recharge groundwater. So it’s not surprising that these valuable areas are protected from most building activities. In many situations you will not be able to drain or fill a wetland or build in the floodplain. Look for the location of wetlands on a National Wetlands Resource Inventory Map published by the US Fish and Wildlife Service (USFWS). Floodplain locations may be found on a Federal Emergency Management Agency (FEMA) Floodplain Map. Cost-share funds and tax benefits are available to enhance wetlands and streamside areas for wildlife habitat. Maps and funding information are available at your local Soil and Water Conservation District (SWCD) and USDA Natural Resources Conservation Service (NRCS) office.

The Right to Farm

It’s peaceful and quiet in the country. That is, until your neighbor fires up the tractor and needs to harvest at night. You may live next to farmers whose livelihoods depend on growing crops and livestock. Don’t be surprised if farm activities bring noise, chemical sprays, dust, and odors. Use this as an opportunity to understand what it takes to produce food and fiber. Many counties have "right to farm" laws that protect the farmer’s right to use normal farming activities.

Septic Systems: Installing a New One

Before buying undeveloped property, you should contact the local official for septic system permits. Don’t overlook this essential step! The septic system site will determine the location of the house, well, and other installations. The septic system permitting official may found at your local department of planning, building, community development, or public health, or at the regional Department of Environmental Quality (DEQ) office. Work with the septic system-permitting official to:

• Select a Good Location: Septic systems need gently sloping, moderately well drained ground. Avoid areas with seasonally high water tables, floodplains, slopes steeper than 15 percent, and fractured bedrock. Locate the septic system downslope from existing or planned wells.
• Find the Right Soils: A soil survey may indicate a promising site. However, you will need to have a percolation test done to determine how fast soils can absorb septic liquids.
• Determine the Proper Setbacks: Decide whether a house, well, septic system, and the appropriate setbacks will fit on the property. Is there room for two septic systems—one for immediate use and the other for replacement in the future? A well must be located at least 50 feet from a septic system and 100 feet from a drainfield. Work with your permitting official to determine the setbacks needed from septic systems, buildings, property lines, cliffs, streams, and water lines.
• Decide on the Type of Septic System Needed: If the site investigation indicates poor soils for a conventional septic system, you may be able to use an alternative system. Alternative systems are usually more expensive and may require special maintenance and approval.
• Include a Contingency Clause in the Contract of Sale: If possible, make the purchase dependent upon finding suitable soils for a septic system.

Septic Systems: Checking an Existing One

• Ask When the Septic Tank Was Last Pumped: Tanks should be pumped every 1 to 5 years depending on the household and soils. Check the age of the septic system. Up to 50 percent of all septic systems fail within 25 years. However, some systems that were installed in the 1930’s have been well maintained and are still working.
• Check How Fast Toilets and Sinks Drain: Toilets and sinks that drain slowly may indicate a waterlogged or clogged septic system. Such systems often need to be pumped or replaced.
• Find the Location of the Septic Tank and Drainfield: The areas should not be unusually lush, smelly, green, or wet with seeping sewage. These are signs of a failing septic system that may need to be replaced.

Wells: Installing a New One

If you are looking at property without a well, get a drilling estimate from a licensed well driller. Also, consider the following to protect your future well:

• Locate the Well Upslope and Away from Pollution Sources: When a well is polluted, the cause is usually located at or very near the well. Avoid placing a well in depressions, drainages, or flood prone areas that may add polluted runoff to the well. The well should be located at least 50 feet from the septic tank and 100 feet from the drainfield. The well should also have minimum setbacks from fertilizer and pesticide storage, livestock yards and buildings, and manure piles.
• Install a Proper Well: A well is a direct pipeline from the soil surface to the groundwater. Pollutants most often enter wells through a poor seal at the top of the casing, inadequate casing grout, or a failure to disinfect the well after construction. Get a reputable driller and follow Oregon guidelines for well installation.
• Prevent Backflow Into the Well: During a power failure, most wells have a single check valve to stop the water column from falling back into the well. If the valve leaks (and many do), water flows back into the well and creates suction. Avoid sucking pollutants into your well by installing simple vacuum breakers on faucets and heavy-duty valves on lawn-sprinkling and irrigation systems.

Wells: Checking an Existing One

More than 500,000 Oregonians get their drinking water from private wells. If you are considering a home with an existing well, here are some things to ask about:

• Recent Well Test: When a home is sold or transferred, Oregon regulations require homeowners to test domestic well water for nitrate and coliform bacteria. If the test results are satisfactory, taste the water. The water will likely taste different because wells are not chlorinated and have different mineral contents. If you notice an "off" taste, stained fixtures, or lead or copper pipes in the home, you may want to request additional tests.
• Well Report and Pumping Rate: Your local watermaster may have a record of the well depth and the conditions at installation. A domestic well should produce a minimum of 5 gallons per minute (gpm) for a three-bedroom home, but 10 gpm is better. Lower flow rates may be acceptable if water can be stored (e.g., in a pressure tank). Note any changes in water pressure when you run a faucet and flush the toilet at the same time.
• Well House Inspection: Check the well house and note cleanliness, the casing condition, and proximity to potential pollution sources. The well should be located at least 50 feet from the septic tank and 100 feet from the drainfield. Fertilizers, pesticides, fuel storage tanks, and animals should be located away from the well house.
• Abandoned Wells: Determine whether there are any abandoned or unused wells on the property. Abandoned wells that are susceptible to pollution need to be properly sealed.

For Help

• The permitting department for septic systems is different in each county. Contact your local building, planning, or health department for the permitting official in your county.
• Oregon Water Resources Department (WRD) and Oregon Health Division (OHD) have well information and installation guidelines. Contact WRD at (503) 378-8455 and OHD at (503) 731-4317.
• The local Soil and Water Conservation District (SWCD) or USDA Natural Resources Conservation Service (NRCS) have soil surveys, National Wetlands Inventory, and floodplain information. Look up your local office in the phone book’s blue pages under federal government, Department of Agriculture.

This fact sheet was produced by the Tualatin Soil and Water Conservation District and the Small Acreage Steering Committee. The Oregon Watershed Enhancement Board, Oregon Association of Conservation Districts, and the USDA Natural Resources Conservation Service funded the project. You may reproduce or copy any portion of these fact sheets for nonprofit and educational purposes by notifying the Tualatin Soil and Water Conservation District at (503) 681-0953. Please acknowledge this publication as the source.