Septic Failure

So I had a septic guy fail a septic system because he ran 3 1/2 gpm into it for over an hour and the water level in the tank was rising. I saw it and it didn’t seem like any of it made it out of the D-Box. He called it out, but the the agent and an engineer who does septic systems said he was wrong, that much water is too much for any septic system, and that he is responsible for any failure since he probably put solids into the D-box.

I always thought 3-5 gpm is what a septic system was supposed to be able to take. I agree with the septic inspector. We have no standards for this in NY though. What is everyone’s thoughts? (There is a NACHI septic course, so feel free to quote it if you want)

3.5 GPM = 210 gallons of water which can overwhelm a system. How old was the home?
What was the system designed to handle, Gallons per day.

Did the inspector dig any inspection holes in the leech bed, if so, did those fill with effluent?

If the D-Box flooded chances are the leech bed is saturated but more information and pictures would help.

Never home, no holes in the leach field. He measured the tank and water volume that entered. The water level raised almost the exact amount of water that was introduced. I looked up the regulations that the septic inspector quoted (one of them being from ASHI) and they all said between 3-5 gpm.

What makes you think it is too much? Just curious.

*Newer, not never

Because most modern septic systems are designed to handle X amount of water per day. A typical three bedroom home, here in NH, would handle 450 gallons per day. The way it’s calculated is each bedroom would average two occupants, each person on average uses 75 GPD, so 150 gallons per bedroom X 3 = 450 GPD. All septic system are designed as a slow dispersal of effluent through the leech field over the course of the day. To introduce 1/2 a days water through the system in an hour could overwhelm the system, depending on it’s design capabilities.

To truly evaluate a septic system you need to dig inspection holes in the leech field to determine how well it drains, without doing that your only guessing. Not sure what methodology the other inspector was following but system failure occurs when the leech field can no longer contain effluent, which may be the case here if it backed up into the D-Box, but again without digging any holes in the leech bed you can’t determine if it’s saturated.

Check out my website, good info there.

Also check out this thread I started a few years ago, you’ll see many pictures throughout the tread on how I evaluate septic systems and why it’s so important to dig inspections holes in the leech bed or EDA (Effluent Disposal Area) as referred to in NH.

Thanks for the feedback, and nice site. What water flow do you recommend? Also, is there licensing/regulations in your State for septic inspectors?

The only thing I can say for that septic inspector is that he had references to back up what he said. I have seen him do several other inspections as well and they were all able to handle the water he put in there. If the leach field had typical length laterals (let’s say three of them), a 1,000 gallon tank, and was done within the past 10 years, how much water should it handle? BTW - there were water reducers in all the toilets on the inside of this house.

Thanks, and I appreciate your feedback.

Your welcome. No regs here in NH for septic evaluations but we have a trade association who has a very good training program.

How much water the system can handle is irevelant as the leech field, as it ages, loses it sieve capabilities or ability to drain. As that happens the material will turn from it’s natural color to gray and then black. Other factor need to be considered such as maintenance. Discharge from water treatment system can also shorten the life expectancy of the system as well.

I’m surprised you guys don’t dig inspection holes, it’s a fairly accepted methodology in many states.

Most of the septic “inspection” companies around here don’t do anything but pump the tank and stick a mirror and a flashlight down it. It takes them all of 20 minutes or so. The reason I’ve always liked that other inspector is that he opens things up and runs his sewer camera down everything. I know a lot of people don’t like regulations, but there should be more than guys just pumping the tanks and walking away

I know, same thing happens here too. The way I evaluate is the most widely accepted method but there are plenty out there that don’t. I’ve re-inspected several systems that were deemed OK but were actually in poor condition.