How Does a Neighbor’s Property Impact Your Next Septic System Design?

Look over that hedgerow bordering the site you’re evaluating to look for wells, ditches or other factors that may dictate onsite placement or system sizing

Interested in Education/Training?

Get Education/Training articles, news and videos right in your inbox! Sign up now.

Education/Training + Get Alerts

We have spent a lot of column space highlighting how soils, system location and users affect the long-term operation of soil treatment systems. However, a reader recently asked an interesting related question: Are there other things to worry about, such as what is happening on the property next door? This got us thinking about aspects of system siting, installation and design that may be impacted by neighboring properties.

Two obvious items leap immediately to mind because we have seen them numerous times: One is making sure the system to be installed is going to be on the property and not next door. And second is the location of the neighboring well! Numerous times we have looked at systems and then looked past the line of shrubs or other plantings to find the neighbor’s well is too close to the system.

As an aside, we have seen the well issue multiple times after the systems have been approved and installed! Of course, according to those involved, it is because the well is not where it is supposed to be … and then the finger-pointing starts! All required setbacks should be determined relative to neighboring properties as well as your property. This includes buildings, driveways, any part of the other septic system and easements.


Another area where we see numerous problems is easements and covenants. Often this involves the power company or another type of utility. There is a movement in northern Minnesota and Wisconsin to bury electrical lines to avoid trees constantly taking down power lines. Power lines you see overhead may have the potential to be buried, and if the septic system is sitting in this location, there’s a very real possibility it will have to be removed to accommodate the power line. Talking to the power company is important to determine how electricity is supplied to adjacent properties and if any changes are planned.

Right-of-way easement or covenants can also become a problem. These issues take at least two forms; one is where the local municipality, county or state has a road right-of-way identified. These may not be obvious without investigating with the municipality or county highway department. If a system encroaches on the right-of-way, the transportation authority can require its removal.

In waterfront property areas where former resorts are broken up and cabins are sold to multiple owners, we often see access routes to the different properties have been identified that are different from the previous access to the resort. Often these access points have not been used; yet the access remains “on the books” to be used. We have often seen a system sited in one of these access areas, and even though that access point has not been used, the situation has led to lawsuits seeking system removal. The access was created to make sure each property cannot be cut off from service points. Just because it isn’t the common route used in the past doesn’t mean it is not there.

We increasingly see a watershed district or other government authority placing additional requirements for onsite systems. The one we see frequently is when a system is proposed in a groundwater protection area. Additional nitrogen treatment requirements are imposed to protect groundwater. Most often this is to reduce nitrate in groundwater where elevated levels are already found in private or municipal wells. We also see this in place to protect the estuary systems and fisheries when we visit the East Coast.


When we have done work in Arizona, a common restriction is to stay back from washes and other areas that conduct water during rainfall events. Most often, no water is present in these areas for long periods of time, but they can turn into a raging stream carrying large amounts of sediment, including large boulders in extreme conditions. To a person unfamiliar with the area, some of these conduits are not obvious. A discussion with local watershed and zoning officials is worthwhile.

Some consideration should be given to land use on adjacent properties. Is it now and will it continue to be residential in nature? Or are agriculture, industrial or business operations in the area going to expand or disappear in a few years? Agriculture areas often have different environmental requirements involving odors, manure application, fertilizer and pesticide use that could negatively impact the property where you are working.

In our area, agricultural land is sometimes converted to residential lots with onsite systems. In some areas, this land has been extensively drained using tile systems. When these systems are cut off or altered, previous water conditions requiring drainage return. For a homeowner, this means paying more attention to the drainage condition on their property and it also means an aboveground system such as a mound or at-grade will be required. The difference in cost between a gravity-fed system and an aboveground system with pumps and pressure distribution is considerable.

Similarly, in the western states it’s important to identify irrigation ditch locations adjacent to property you are working on. An adjacent ditch can raise the water level during irrigation season, affecting how a sewage treatment system functions.   


Expanding businesses may bring sewer to the area long before it would have ordinarily happened. Ask local zoning authorities if there are plans to expand sewer service. Your customers need to understand their options if sewer or water system expansion is on the horizon.

These are just a few of the conditions we have seen a designer, site evaluator, installer and inspector encounter that could have a major impact on placement and design of new septic systems. From time to time, we expect to revisit this important topic in coming issues.


Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.