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My neighbor has tied into my septic system – What should I do?

The number one answer from property owners is to cut, cap, or fill your neighbor’s lines with concrete and that is the worst advice to follow. There is a possibility that previous owners planned and permitted the “duplex septic system,” a rare but not that unusual setup. We have developed a product specifically covering Duplex Septic Systems.

Before you take any action, go to your county or district health office and check both properties for a letter of interest or an easement. If a legal permit, even an ancient one was issued, you may be out-of-luck to change it even with much time and cost. If a permit is on file, there is likely a community system agreement with how to share costs between properties for repairs and maintenance, and allowance to enter certain parts of each other’s property, etc.

gravity septic systemsIf no permit exists, it is possible that an illegal tap to your system has taken place. That doesn’t mean that either you or your neighbor are permitted to alter the system or change your system into a duplex septic system or cut an existing connection. If two systems are directly connected, either tank to tank, tank to an adjacent drainfield on another property, or even with any pipe connecting one drainfield to another on an adjacent or the same property. This is technically a duplex installation with or without a permit.

Also, it is possible that your systems may both be too old to have permits. An additional connection could have been added before your ownership AND before septic permits were required in your area. Building permits and septic system permits were not always required, especially in rural areas. Local health septic system regulations originate from state or provincial health department guidelines and mandates often years after building permits are required. Septic permits are tailored to regional soil, climate, groundwater conditions, and available technology.

If your system is too old to have a permit, your layout would not be enshrined in a local health database. It would likely be known as a “grandfathered septic system.” This is a legal, but likely “nonconforming” (not exactly meeting current regulations, but working OK) system. This status can last years, provided the system doesn’t fail, and as long as no changes are proposed to the building. Either event would trigger the need to upgrade the system to all current regs.

Almost all counties and planning regions in the US and Canada NOW require wastewater permits whenever new structures with plumbing are planned, plus whenever older structures with plumbing are added to, modified, or repaired. In any case, the authority to redesign, excavate, or modify small to medium sized septic systems is ONLY by county authority. Alteration permits in most cases require a sign-off or work by licensed people, a category that may or more often may not include exemptions for property owners or residents.

Changing any part of an operating system or a sewage collection system could result in a sewage spill, a public health matter. Even removing a bootlegged connection to a system must be “altered” with a local health permit, a sanitary inspection, and often an approved design by a qualified designer or a civil engineer.

Correcting a discovered duplex septic system or designing a septic system serving two properties from scratch.

Whether improving or changing an existing legal connection, bringing an illegal connection into compliance, certifying a grandfathered connection (from before regular permitting,) or proposing a brand-new duplex septic system, the same basic ingredients will be included in the permit application.

1. An inspection of the system by local health OR your licensed designer or engineer may be allowed to perform the initial inspection in most states, provinces, and territories plus local health will discuss with you your options, and how to proceed. In some jurisdictions a licensed excavator, or even the property owner in rare cases may draw up plans and submit them.
2. A Survey by a licensed surveyor would likely be needed showing building locations, surface contours, property lines, easements, and as many of the septic components as are known or discovered via excavation including potable water lines.
3. A design by a qualified designer or engineer will be prepared to show local health what you are proposing. The design will include a site plan showing both properties. all sewage lines, tanks, drainfields, existing and proposed structures, and water lines. The design will likely provide soil information from a qualified expert, and local health can in some cases provide this information to the applicant.

Our module “duplex septic systems” includes a complete model application package including a typical design and a shared system agreement to be signed by both property owners. If your health department requires a perpetual sewage easement allowing certain access to both parties for maintenance and repairs, we include a draft example with the proper wording that would be applied to both properties. A typical draft agreement is included in our package, but your local health office will provide guidance to your specific application requirements. Our products are not intended to be specific to your situation or any existing state or provincial setting. As an applicant or owner, you are responsible for the accuracy, legality, and suitability of all information included in any application to your local jurisdiction regarding any septic system. Our products are designed to help you prepare your submission, but Eco-nomic and its agents are not liable for any loss or damages resulting from their use. Please read the limitations and restrictions that apply to the use of Eco-nomic’s products provided at their point of sale.

Eco-nomic has 35 years of designing septic systems and we also perform hazardous and toxic environmental cleanups. Occasionally both skills are required on the same property, and we guarantee through experience that you do not want to do both, if you can avoid it. If the neighbor’s sewer connection to your septic system is unpermitted, have local health come out and inspect it with you. They are already authorized to enter your neighbor’s property, and you may not. You and your lawyer can take it from there if your neighbor is uncooperative. Do not, I repeat, do NOT alter any system without checking first with local health, because that would make you liable for any consequences, even if your neighbor started it.

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