WHAT ARE UNDERGROUND TANKS?

Tanks are best lifted by a crane using a proper lifting sling. They should only be lifted using the intended grooves on the outside of the tank (see figure below). If the tank placement is self-performed, Tanks-A-Lot can lend out slings for a refundable deposit. Using any other lifting apparatus will cause damage and void the warranty.

• After a septic tank is set, it must be appropriately backfilled. The installer should verify that the backfill material is free of clumps, large rocks, frozen matter and debris that can result in voids in the backfill that may allow settling over time.
• All tanks should be backfilled with successive depth increments of uniform gradation. Backfill should be placed in a uniform sequence to all sides of the excavation. Uneven backfill can cause tanks to shift resulting in leaking joints.
• Each layer should be uniform, no greater than 24 inches thick, and of nearly equal heights around the perimeter of the tank. If the material used is compactable, it should be hand compacted to prevent settling of the soil around the tank. Be sure that the method used to compact the material does not compromise the structural integrity of the tank. Mechanical compaction should not be used and will void the manufacturer’s warranty.
• All pipe connections through tanks must remain watertight after backfill. It is critical to ensure there is minimal movement of the inlet and outlet pipes during the backfill process. Tamp the backfilled soil under the pipe to give it a firm foundation. The section of pipe that runs across the excavation from the tank to undisturbed soil should be rigid (Schedule 40 PVC or stronger) to eliminate deflection. The pipe joints should be over native soil rather than in the excavation to ensure they do not settle. Pipes that may run over the top of the tank or in excavated areas (such as electrical conduit and/or effluent lines) can be sleeved in larger pipes to provide extra support.
• Tanks come with a 4″ flex inlet for pipe connections. In instances where these are not used, it is recommended that the inlet be filled/patched in.
• Refer to the manufacturer’s installation guide for more details.

• Many tanks are constructed in two pieces that are joined either before the tank is delivered or after it arrives at the site. The seam may be located near the midsection (midseam). Regardless of the location, the seam must be rendered watertight for proper system function.
• For concrete tanks, a butyl rubber or asphalt-based (bituminous) mastic is placed in the seam before the pieces are joined. The seams to be joined should be clean and dry. Primer should be used to help the sealant adhere to the concrete surface.
• At Tanks-A-Lot we stock and recommend ConSeal CS-75 Surface Primer.  ConSeal CS-75 enhances the bonding between preformed sealants and concrete surfaces aiding in the installation process. Conveniently applied at the job site, CS-75 improves adhesion of the sealant to the concrete.

To Apply:

• Clean the surface with a brush and remove any dirt, debris, flashing, or concrete high points, which could keep ConSeal primer from adhering to the concrete.
• Allow the primer to dry before placing sealant. CS-75 will be tacky within 15-20 minutes.
• ConSeal CS-75 is an adhesive primer that dries tacky. It is waterborne and does not contain volatile or flammable components. Open the pail and apply the product using a standard paintbrush or paint roller.

How much weight can a septic tank withstand? There is no straightforward numerical figure as to the weight pressure that an underground tank can endure. However, you should know that everyone is advised to avoid driving and parking vehicles or heavy machinery over or near a tank location. Subjecting your underground tank to heavy weight from cars, trucks, or tractors, construction equipment, etc. risks damaging the tank. Driving, parking, or building infrastructure over tanks risks damaging your tank, possibly leading to a cave-in.

Unless special provisions have been made such as protection of sewer piping and septic tanks from damage, vehicle-rated septic tank covers or similar steps, do not drive vehicles over septic system piping or septic tanks. A property owner may not immediately recognize a septic system problem when piping has been run below a driveway, as crushing and blockage of the line may not happen until a heavy vehicle enters the driveway (such as the loaded septic pumping truck arriving to pump the septic tank). A septic line may also be broken, permitting soil or roots to enter and complete the clogging process. Driving over or near and damaging a septic tank can result in leaking, a later cave-in, fall-in, or extremely serious hazards.

Here are some best practices to follow:

• Septic tanks should never be built underneath driveways or garages. Your septic tank is ideally situated underneath a soft area of land and away from traffic. If at all possible, mark off the area under which your septic tank is placed. This is so you can be sure not to drive over it and, more importantly, never to park on top of it.
• Water hauling trucks and vacuum trucks should be kept at least 15 feet away from tanks due  to their weight.  Almost all trucks will have enough hose to be able to keep a safe distance.

Vehicle traffic over or near your tank will void the manufacturer’s warranty.

• Tanks in high water tables can be subjected to outside hydraulic pressure. While rare, if this pressure is strong enough water can be forced through seams and joints. As part of our standard installation procedure, Tanks-A-Lot recommends wrapping any seam or joint with a mastic seal such as Sopraseal or Henry’s Blueskin. These products are applied with a coat of adhesive first and then mastic is wrapped around any joint or seam.  Installation is simple, quick and cost effective, and should be done after the tank is placed in the excavation to ensure the seal is not compromised during lifting and/or transportation.
• 2 piece tanks must be done at site by a wastewater professional.
• If additional waterproofing is required due to site conditions, custom concrete using Xypex waterproofing additive can be made. Xypex is a unique chemical treatment for the waterproofing, protection and improvement of concrete. Xypex is added to the concrete mix at the time of batching.
• Speak to a Tanks-A-Lot Sales representative if you think your project requires Xypex.

During a siphon cycle, the siphon traps must be filled with water. When liquid rises above the open end of a pipe called a snifter or vent pipe, air is sealed in the bell and long leg of the siphon. As the fluid in the tank rises, the pressure on the confined air increases and forces water out of the long leg of the trap. When the air pressure is great enough to force all the water out of the long leg, trapped air escapes through the short leg to the air release vent pipe. At this point, the siphon has been “tripped” and fluid is discharged from the siphon until the liquid level in the tank drops to the bottom of the bell. Air is then drawn under the bell, which “breaks” the siphoning action, and the process begins again.

Troubleshooting:

The most common problem you’ll find is the siphon trickling or leaking effluent rather than providing the expected dose.  This is called a trickling siphon or a siphon that has lost its prime. When a siphon has lost its prime there is a loss of air pressure under the bell. Lack of air volume under the bell means the liquid level will not achieve the necessary head to drive the effluent into the distribution system.

Another situation that can cause problems with siphon operation is when a home is intermittently occupied. These include lake homes, vacation cabins or snow birds that leave the north for warmer climates. If the water level is high when they leave, air can diffuse into the effluent over time, which reduces the air volume and causes trickling.

One of the most common issues seen is the bell being installed upside down.  The open end of the bell must be facing downwards as shown in this picture.

• Normal household amounts of detergent, bleach, drain cleaner, toilet bowl deodorizer and other chemicals will not harm the bacterial growth in the sewage tank system.
• Do not deposit coffee grounds, cooking fats, wet wipes, disposable diapers, facial tissue, cigarettes and similar non-compostable material into the septic tank. Place these items in your trash can.
• Use toilet tissue that breaks up easily when wet. There is one available that is specifically for use with a septic tank.
• Sludge buildup should be checked by a wastewater professional and cleaned by a service provider.
• If you have a garburator you may need to have your tank cleaned yearly.
• Call a vacuum truck to empty and clean your septic tank every 2 to 3 years depending on use.
• Be conservative with your use of water. Repair all leaky fixtures and reduce the amount of water used in laundry, bathing and toilet flushing.
• Wash only full loads of laundry. Spread the laundry out over the week to avoid overloading the sewage system in a single day.
• Showers typically use less water than baths. Avoid filling the tub to full and do not turn the shower on full. This could save several gallons with each bath or shower.
• Routinely check the toilet float valve to be sure it isn’t sticking and leaking. Do not flush the toilet unnecessarily.
• If your system is used seasonally, ensure there is 1 foot of fluid remaining in the tank for the offseason, this will help prevent frost heaving.
• Do not allow water softening devices to discharge into the septic system.

Tanks-A-Lot sells septic pump hookup kits. The benefit of using this kit is the ability to disconnect the union to remove the pump for replacement or servicing without entering the tank. Inside this fittings kit are all the fittings required to assemble the connection shown in this diagram. It is important to drill a 3/16″ hole, as shown, to allow the line to drain back after the pump turns off.
The Septic Hook Up Kit can be purchased from Tanks-A-Lot in either 1.5 or 2 inch fittings.

• Place a layer of mulch 8 to 12 inches thick over the pipes, tank, and soil treatment system to provide extra insulation. This can be straw, leaves, hay or other loose material that will stay in place and not become compacted. This is particularly important for new systems that were installed so late in the year that vegetative cover didn’t get established. However, if the system is currently frozen, don’t add mulch now; it will delay thawing in the spring.
• Use water—the warmer the better—if you’re worried your system is starting to freeze. Spread out your laundry schedule so you run one warm/hot load a day. Use the dishwasher and take hot baths. Do not leave water running all the time—this will overload the septic system.
• When going away for an extended period have someone use warm water in the home regularly or pump out your tank before leaving.
• Fix any leaky plumbing fixtures or appliances in your home. This will help prevent freezing problems and help your system perform better all year.
• Keep all vehicle, snowmobile, animal, and people traffic off the system. This is a rule to follow all year as compacted snow and soils cause frost to go down deeper and faster. Pay special attention to the area between the house and tank.
• Keep an eye on your system. If any seeping or ponding occurs, contact an onsite professional to help determine the cause and remedy.
• Add more insulation to your system. This could include replacing pipe with insulated pipe, adding expanded foam panels over septic tanks, or adding more soil cover.
• Do not overfill cisterns. Water in the manway is susceptible to freezing and can damage the manway or tank.

Please refer to the table below to troubleshoot your effluent pump.

This issue is seen in both septic and cistern tanks.  Although there is no right or wrong, plastic fittings can have a tendency to shear off if the ground shifts during settling or frost heaves during winter. The best practice when using brass would be to use a 90 degree elbow to deflect any force applied on the fitting. If using plastic fittings, the best practice would be to sleeve the fitting with 4” plastic pipe. The indent around the outlet is designed for this purpose.  This length of 4” plastic pipe needs to be long enough to bridge the space of backfilled soil around the tank.  This will add a rigid structure in case of ground settling or heaving.

How to identify this is the issue:

• Soggy ground near tank
• Cistern tank may empty to level of outlet inside tank(18 to 22 inches)
• No water pressure inside of house
• Refilling cistern more often than usual
• No pressure to septic treatment field