How to Install a Septic System

Septic systems, are used primarily in rural areas of the country where waste water treatment is not available. These systems fall into two general categories.

1. gravity fed/conventional and 2. alternative (pump) systems including aerobic treatment units (ATUs.) Alternative systems usually include electric pumps. This is a project recommended for a professional like Murphy's Cesspool & Septic Service with experience in the field due to the potential risk to environment by pollution of the watershed.

Prepare & Design Your System

The first step in any septic installation is to perform a site survey and do a percolation (soil) test on the area where the Septic Tank is going to be installed. The system then can be designed based on the findings of the survey and results of the soil test. After this, the appropriate permits and approvals can be applied for.
Site survey findings that influence the design include things like:

Soil test Findings that Influence the Design Include things like:

Soil Type and Layering (sand, clay, rock, and where it is located relative to depth)
Ability of the Soil to Drain and Filter Wastewater.

Necessary Equipment to Install A Septic System

Placing The Septic Tank

Excavate to at least 2 feet deep and drill a hole through the wall, or go deeper and go under the footing, whichever is desired, or necessary. Plan for the flow to go downhill from here, as this is exactly what a gravity fed system is all about. It does not use a mechanical means other than gravity to discharge the waste from the tank to the drain field.
Pipe 4" Sch. 40 going a foot through the wall or under the footing, and to a minimum of five feet outside the building toward the tank. Set it level where it's going through the wall or under the footing, and from there run with about an 1/8" per foot of pitch (slope) toward the septic tank. Go further or all the way into the tank if required. If not, switch to 4" 3034 with the appropriate adapter and pipe toward the tank with 3034.
Be sure to put a test cap on the end going into the building. If going through the wall, seal around the hole with hydraulic cement, inside and out.
Don't run too much pitch going out to the tank. If there's too much, the water runs away faster than the solids, and the solids may get left in the pipe. Also, there may not be enough pitch to get to the drain field, depending on the depth your drain field is, and how close it will be to the outlet of the tank.

Excavating The Septic Tank

Excavate a hole large enough to set the concrete aerobic tank below ground. Use the laser transit and "shoot" the top of the pipe going out to the tank. Measure the distance from the top of the inlet, to the bottom of the tank. Add this (go up on the grade pole) plus 1 1/2" to the number you shot off the top of the pipe. The grade pole is now set to the depth that you need. Proceed to use this to excavate the hole to the appropriate depth.
Lay out and excavate your leech field as it has been determined by the test done in the permit process. When laying out and excavating, remember to maintain a positive flow between the tank and the drain field.

Place (in most jurisdictions) "inch-and-a-half washed drain rock" from a nearby gravel pit around the pipe. This is required to hold the pipe steady. See your Suffolk County local health requirements for the size of embedment needed or contact Murphy's Cesspool & Septic Service The perforated pipe in a gravity drain field has no slope end to end and has capped ends.

Cover up the pipe and tank once you have a green tag from the health inspector. All areas depending on the rules of the local health department will require a special filter fabric, newspaper, four inches of straw or untreated building paper to cover the drain rock before backfilling.

Installing a Pipe Chamber

Install a pump chamber after the septic tank. The pump chamber or sometimes known as a pressure tank, or dosing tank contains the electric pump which is utilized to move the effluent from place to place, and eventually into the drain field for final disposal.

Set up the pump chamber as you would the septic tank. The pump chamber contains the effluent pump and floats to pump out to the drain field at measured or timed intervals. This is a sealed system. The electrical installation will usually require a licensed electrician to satisfy state regulations. In areas with high ground water, be aware that the pump chamber or additional ATUs may be mostly empty much of the time, and these tanks may have to be protected against flotation by the use of extra weight or other protective structures.

The construction details including the layout of all sewers outside of the home, the location and depth of all tanks, the routing and depth of pressurized effluent lines and other system parts such as the drain field and any additional ATUs must match the septic system plans as approved by the local county health department.

Cover the tank and pressurized lines once the inspector has given his final approval and the system is activated.

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Cesspool & Septic Service, Nassau County & Suffolk County, Long Island, NY