Shut It Down

Just like when you install a new onsite system, abandoning an old system requires following a careful list of safety procedures.
Shut It Down
In this case of an abandoned septic system, the contractor chose to remove the old tank. (Photos courtesy of Jim Anderson)

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As an installer, at some point in time you will be asked to abandon an existing system or part of a system as part of the new installation. Some general guidelines should be followed as a part of this process, and state and local requirements usually dictate how this should be done. The process is designed to focus on protecting the health and safety of people that may come in contact with the area of the system.

Added to the accepted and required practices, you must consider the homeowners’ desires regarding how they want to utilize that area of their yard in the future.

The first step of abandoning a system properly is to make sure future discharge to the system is permanently denied. This means all piping from the residence or other establishment is either removed or permanently disconnected. The importance of this step was brought home to us a few years ago when a system was not properly abandoned, the tank area left with voids and the piping from the business still intact. There was a huge rain event and the tank area filled with water, which was able to flow back from the tank into the business, flooding the business offices and causing great damage. All this happened because the system was left connected and the tank was not properly abandoned.

The abandonment procedure for sewage tanks, pump tanks, tanks as part of advanced treatment, cesspools, seepage pits, drywells, vault privies, pit privies and distribution devices is the same. Often polyethylene and fiberglass products are removed, while concrete products are abandoned in place.

Any tank should be pumped empty. All solids and liquids should be removed. A note here to the service providers: The contents must be disposed of according to the state and federal rules governing septage. Make sure the tank contents fit the septage definition and are not another kind of waste that should be handled differently. Determine this before you have the waste on the truck so you know ahead of time where you are taking it for treatment and disposal. Installers: Most states require a licensed maintenance business handle this waste. So if you are not licensed for this activity, work with someone who is.

Cesspools, seepage pits and drywells should be pumped empty as well. They should then be filled with clean granular material that is compacted to prevent differential settling and to prevent any cavities in the fill from forming or being left where someone could fall in the future.

Remove all the lids and risers and salvage or recycle them. If recycling isn’t an option, take them and any piping removed to a mixed municipal solid waste landfill as determined by local requirements.

If there is a pump or pump tank in the system, disconnect the power at the source, and remove all controls and panels that are not going to be part of the replacement system. Any devices such as floats that have mercury switches should be set aside and handled as a hazardous waste and disposed of according to state and local requirements. All electrical lines that serviced the pumps, floats and alarms in the system should be removed if they are not going to be reused.

Similar procedures apply for additional pretreatment components contained in tanks, such as ATUs and media filters. The contents, including media, should be removed and disposed of in the appropriate landfill. Distribution networks in the pretreatment device can be included with other piping components for disposal. For ATUs where pumps and blowers or compressors may be involved, they should be removed and recycled or salvaged if possible, or taken to the landfill. As with pump tanks, the electrical components and wiring should be disconnected and removed.

All of these same procedures, including removal of salvageable parts, apply for media filters that consist of some type of modular units, such as peat filters. The peat should be removed with a vacuum truck designed to handle that level of solids. Rock providing drainage at the bottom of the module should also be removed, and the module itself should be removed. This will probably require excavating around the module so a harness can be attached, and then a crane or excavator removes it for reuse or disposal. The cavity or hole from the module should be filled with a compacted granular material to prevent settling and the area graded, topsoil added and vegetation established.

If the tanks are not removed, they must be collapsed or crushed in a manner so that the tank or the cavity for the tank will not hold water. For concrete tanks, this means the bottom of the tank should be broken up to allow water drainage. Fill the tank with a debris-free granular material like sand. The material should be compacted to prevent settling. The rehabilitated area should be graded, topsoil applied and vegetation established consistent with the homeowners’ desires.

Next month we will focus on the proper abandonment of a soil treatment area.


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