Dutch_12078 wrote:
Most standard (non-HE) top load washing machines in use today can use as much as 40 gallons of water per load. Toss in a shower or two, or a bath, and you can easily exceed a 50 gallon discharge in a short time. Most septic tanks have enough head room to accommodate a temporary backup from the leach field if needed. The scum layer just floats up higher.
Not the same. The washing machine isn't dumping all 40 gals at once but only a percentage of the 40 gals over a period of 30-60 minutes. A washing machine will only dump 5-7 gal at a time at the end of each cycle.
A septic tank water level will be equal to the bottom of exit port in the tank and below the inlet port.
Overflowing a septic tank one time is not likely to damage the leach field. It's the accumulated effect over a period of time that causes the damage.