Septic or sewer backup prevention:

This document explains how to avoid septic system backups when heavy use of the system is anticipated and for homes connected to a municipal sewer we discuss how to prevent sewer or storm drain backups into a building during rain or heavy flooding.

Guide to Avoiding Septic Backups During Heavy System Use

I bought a home in August 2007 that uses a 2000 gallon Septic Tank.  At that time, it was inspected, possibly pumped out and was in fine working order.  We are a family of 4 and for us, we’ve had no problems. 

On occasion, we have maybe 8 people visit at a given time.  We are expecting about 60-70 people over for a Birthday Party and my husband is freaking out! 

He thinks the septic tank will back up into the drains if we have that many people using the toilets, over a 6 hour period.  My question is: Is my husband correct in thinking that way, will the septic system back up?   Could you PLEASE answer these questions  AS SOON AS POSSIBLE? The party is on 04/26/08.

Why Does the Septic System Back Up During a Party?

Indeed it seems to be just the luck that we are living happily along not giving the septic tank a thought until we have a bunch of guests over for Thanksgiving, Chanukah, Christmas, or a graduation party. Why is it that at events we often see the septic system backing up?

The explanation is that a septic system that backs up during a party was already in trouble, but our usage was modest enough that we just weren't noticing it. The surge of waste water entering the septic tank cannot flow into a flooded drainfield so sewage may back up into the home, usually at the lowest plumbing fixture.

Sometimes it's not the wastewater surge but someone flushing something down a toilet that blocks a drain - that's a problem that can be cleared by a plumber using a plumbing snake or drain router. But often the problem is in the septic field itself.

Here are some simple tips for avoiding a septic backup during times of surges in use such as during a party

1. Pump the septic tank before the party: When a septic system is otherwise in good working condition, the septic system stress created by having many people use the sinks, showers, and toilets over a short time is not so much the solid waste as the high wastewater volume in gallons.
   
   Very high water usage over a short time can flood a drainfield or septic mound which in turn could cause a septic backup. Pump the septic tank tank right before the event, or the day before. This will give some extra capacity to absorbing this high use resulting in a sudden surge in wastewater volume.


2. Avoid using water unnecessarily after pump out. That means don't leave running toilets un-repaired, don't leave water running unnecessarily.
   
   See WATER QUANTITY USAGE TABLES for a table of typical daily residential water usage under normal conditions.


3. See TOILETS, DON'T FLUSH LIST for a list of things that should not be flushed into a septic system: a list of what's ok and what's not ok to put into septic tanks and building drains.Some of these can cause a system drain blockage and thus a sewage backup into the home.


4. Regular septic system maintenance, pumping on schedule, is the long term way to protect the system tank and drainfield from early failure and thus to protect from septic system backups.
   
   See SEPTIC CLEARANCE DISTANCES and
   
   see Ten Steps to Keeping a Septic System Working for a more thorough discussion of how to care for a septic system, or review our complete list of septic maintenance articles
   
   at SEPTIC SYSTEM CARE GUIDE
5. See BLOCKED DRAIN REPAIR METHODS for simple methods to clear a blocked drain yourself.
6. Provide additional or emergency toilets when an unusually large group of people are expected at a site served only by a normal residential septic system, consider renting one or more port-a-potty toilets from a local supplier.
   
   This is an especially good idea if you already know that your septic system is old, failure prone, and/or of limited capacity.
   
   See CAMPING & EMERGENCY TOILETS.

How Much Wastewater Will Be Produced by 60 Visitors During a Party?

In the email example above where our writer assumed there would be up to 70 people visiting the home over a 6 our period, if every visitor uses the bathroom and at each use flushes a toilet twice, that'll be 120 x 4gals = 480 gallons which will be less than the septic tank can hold.

So if otherwise conserve water, we have a typical home septic tank of 1000 gallons or larger, and if we start our festival with the tank nearly empty, we're sure to protect the drainfield from flooding during the event.

If the septic system is already in good working order you should be ok.

If your drains are already backing up, especially during a time of heavy use such as with guests in the home,

see SEPTIC BACKUP REPAIR.

If toilets are overflowing or not flushing,

see TOILET OVERFLOW EMERGENCY.

Guide to Preventing Septic or Sewer Backups Due to Flooding or Sewer Main Backups

Please see our full article on this topic, found

at SEWER BACKUP PREVENTION

...

Continue reading  at BACKWATER VALVES, SEWER LINE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see BACKUP PREVENTION, SEPTIC FAQs - questions & answers posted originally at this page

Or see these

Septic or Sewer Backup Articles

• ADDITIVES / TREATMENTS for SEPTIC SYSTEMS
• BACKUP, SEPTIC-SEWAGE WHAT TO DO
• BACKUP PREVENTION, SEPTIC
• BACKUP PREVENTION, SEWER LINE
• BLOCKED DRAIN REPAIR METHODS
• DRAINFIELD FAILURE DIAGNOSIS
• SEWAGE BACKUP TEST & CLEANUP
• SEWAGE BACKUP PREVENTION - home
• SEWAGE CLEANUP PROCEDURES & STANDARDS
• SEWAGE CONTAMINATION in BUILDINGS
• SEWAGE EJECTOR / GRINDER PUMPS

Suggested citation for this web page

BACKUP PREVENTION, SEPTIC at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to SEPTIC SYSTEMS

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Citations & References

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