Pumping Out Your Septic Tank is Not Always A Good Idea. Here’s Why.

You often hear and read about why and when you should pump out your septic tank, but you never hear or read about when you SHOULDN’T. Do you ever wonder when it is a bad idea to empty out your septic tank? In some situations, pumping out your septic tank could damage your septic system. Here are some possible scenarios where this is a bad choice:

1. When the Septic System is Flooded By Water

If your property has been flooded by water due to a major flood or river overflow, pumping out a septic tank while the soil is still very wet could cause some problems you didn’t expect:

• If the septic tank is made of plastic or fiberglass and the groundwater is still high around it, the tank may float up out of the ground. This could damage the septic pipes and lead to more expensive repairs.
  Wait until the floodwaters and groundwater around the septic tank have gone down.
• Floodwaters, including silt and mud, may flow into the septic tank (even if the tank is concrete), filling it with silt and debris that must be removed.  It is best to wait until the waters have gone down and the groundwater is low enough that mud and silt and debris won’t just run back into the tank.

1. If a Septic Tank is Old or Fragile, Don’t Pump Without Inspecting

An old on-site septic system made of dry-laid stones or concrete blocks may fall apart when it is pumped or soon after. Here are some things to keep an eye out for when inspecting:

• The sewage and water in a septic tank that has never been used should be taken out. If a septic tank was set up during very rainy weather, it’s possible that a small amount of water got in while the tank was being set up. However, that’s not a common thing to happen. If there is more than an inch of water in the septic tank, it is possible that surface runoff or groundwater is leaking into the tank and flooding it. Look for stains on the inlet pipe, baffles, covers, and tank sides, which could be signs that water is leaking into the tank. 
• If the distribution box has fallen over or there is evidence that surface water is getting in, these problems will need to be fixed. 
• Make sure that the covers on the septic tank are safe and secure.

1. Do Not Pump the Septic Tank Right Before a Septic Inspection and Test

When a house is being sold, realtors often pump out the septic tank right before the septic test and inspection.  This is because pumping a septic tank shortly before testing Pumping a septic tank right before a test makes it impossible to get an accurate evaluation of the septic system. This means that already existing septic system problems would stay hidden which would therefore present the new buyer with a costly surprise that could have been discovered before the purchase.