# Will a cart jetter do this job?



## Western (Jan 25, 2011)

We were out this morning to dig up a septic drain field to diagnose the reason for failure. I had told the owner that we might try jetting the laterals as he is looking to stay as cheap as possible and hopefully buy another year or two on replacing it.

The field comes out of the tank about 10' or 12' and tees into the field, which consists of three 35' laterals on 10' centers, with the ends looped together and a tee in the center line so everything is connected, sort of like an absorption bed except it's in separate trenches. I explain this so you guys will know how much pipe were talking about. It adds up to about 155' of 4" pipe.

We cut out one of the T's at the end of the center lateral and found heavy sludge, which is what I was hoping for. Now we have positive proof that the perforations are clogged and that jetting will probably help.

However, this thread is not a question about drain fields. I have given as much information as possible so you jetter guru's out there will be able to provide me with a solid answer. We are going to be jetting this field in the morning using a subcontractor with a US Jetting 4018. However, as most of you know by reading my previous threads, I'm tired of leaving all this jetting money on the table and want to do it myself, so my question is as follows:

I have always thought I would need a fairly large trailer jet for this type of work, something in the range of what my subcontractor uses. Lately I had almost decided to start with a large cart jetter. Given the specifics of this job, I'm having some doubts about whether I'd be really happy with a cart.
155' of 4" pipe 3/4 full of sludge is a lot of sludge. Really, what kind of luck am I going to have with a 6 gpm @ 4000 psi cart jet? I realize it's going to do the job with enough time, but if it would take me half a day to do with the cart I'd better go with the trailer. Like I said, this particular job is scheduled with a sub, but it's far from the last time I'll face similar situations, so if I'm going into jetting I've got to use the situations I encounter to make sure I get the right equipment when I do.

Anyone with experience, let me know what you think.


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## SlickRick (Sep 3, 2009)

http://www.plumbingzone.com/f23/septic-line-cleaning-6625/


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## Western (Jan 25, 2011)

Thanks, Slick,

The majority of our work is septic and that's where we claim to have the most expertise. I looked at the thread you linked and I can totally see your point if you are using cable equipment after the tank and/or D-box. We have had fairly good success with jetting them in certain cases, although with regards to your thread jetting a drainfield should only be done with careful thought and selection and after a thorough investigation as to the type of failure. You cannot expect to jet and recover nearly all failing drainfields, and especially not hydraulically overloaded or biologically failed (excessive biomat) drainfields.

However, being experienced in septic work I can usually identify the reason for failure. I'll give you my diagnosis here so you can see what we are looking at:

Clue #1. The HO told me that the tank had been pumped recently but before that it had been 15 years. This made me think suspended solids had probably travelled to the field and settled out there.

Clue #2. The national average for wastewater generated per person per day is around 80 to 85 gallons/person/day. This is the information we use when sizing drainfields. We pumped their tank and checked the depth exactly 24 hours later and were surprised to find maybe a couple hundred gallons in the tank max, which means that these people are not using an excessive amount of water, nor are there major leaks in plumbing fixtures that would cause excessive amounts of water going to the system and causing a hydraulic overload failure.

Clue #3. I went to the county and pulled up records of the permit. It showed a pipe and gravel system. A lot of solids that migrate out of a tank will settle out in a pipe. We have had very good results in these particular cases by jetting using a thruster nozzle and pulling the bulk of the sludge back into our excavation, working a little at a time, and vacuuming it up with our septic truck. If the system is a chamber (Infiltrator or equivalent) system, the solids settle in the chambers and seals of the infiltrative surface. These systems are completely destroyed and must be replaced.

Clue #4. We dug up the field lines and found a fairly light biomat, and there was not an excessive amount of water that would indicate a hydraulic overload caused by overuse of water. The water level was well below the pipe. 

Clue #5. We cut the tee out as stated and found heavy sludge, which confirmed Clue # 1 and gave us good reason to pursue the option described in Clue # 2.

Again, these are only clues, but the evidence looks fairly conclusive.

My question is really what size of jet it will take to backflush that amount of sludge into the hole. Will it take a cart or a trailer? We are fairly certain based on the evidence and our previous experience and success that this particular field can be made to accept effluent a while longer by jetting it.


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## SlickRick (Sep 3, 2009)

What you are saying makes the most sense to me so far. Our area is mostly rural. I am glad to hear there is some logic to determine that cleaning is a option.


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## Western (Jan 25, 2011)

SlickRick said:


> What you are saying makes the most sense to me so far. Our area is mostly rural. I am glad to hear there is some logic to determine that cleaning is a option.


Really wasn't trying to be a smart you know what.  Just showing you my logical flow chart.


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## RealLivePlumber (Jun 22, 2008)

You're gonna be a dirty boy at the end of the day. :thumbsup:

My kinda' guy.


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## SlickRick (Sep 3, 2009)

I didn't take it that way. I would love to be able to offer a temp alternative solution to replacement. I am not trying to jack your thread. post some responces to questions on the link I posted about cost, guarentees, etc. I have a market, and the will to do it. I think one guy said he charges around $700.00. I am not taking my equipment out for under $1500.00. It sound more like a $3500.00 job


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## Western (Jan 25, 2011)

SlickRick said:


> I didn't take it that way. I would love to be able to offer a temp alternative solution to replacement. I am not trying to jack your thread. post some responces to questions on the link I posted about cost, guarentees, etc. I have a market, and the will to do it. I think one guy said he charges around $700.00. I am not taking my equipment out for under $1500.00. It sound more like a $3500.00 job


Thanks, Rick,

After reading that thread extensively and observing all the mud slinging and juvenile quarreling that went on there, I decline to show my avatar on that thread. There is a lot of misleading information and a lot of uninformed people spewing wastewater treatment pseudo-science there. Maybe someday a Septic Science 101 thread would be in place, but it would have to be lengthy.

However, back to jetting drainfields, I will tell you here that it's typically a desperate attempt to buy time when a homeowner is having problems but can't cough up the money to replace the system. It will not be attempted if there is a public health issue such as sewage on the surface, which indicates hydraulic failure anyway so jetting would be ineffective. We clearly explain to the homeowner how a septic system works, the biomat growth, variables in lifestyle that can impact their systems, and then clearly state that there is no guarantee that it will restore their systems. We tell them we are careful which ones we do and that we have had good luck on those we have done, but again we cannot guarantee a remediation. 

As far as cost goes, it depends how they go. Some of them we have done when we were already onsite pumping the tank, they had good access through the outlet baffle, and they went really well, in and out in an hour or so. These jobs only get charged a normal jetting charge above the normal tank pumping charge, say around $500-$700. Others, like you described in the other thread, require an excavator, a jetter, and a vac truck. These are more costly, in the $1,000 to $1,500 range depending on the logistics required to make it happen.

It may be that our market is way softer than yours. In our area for the $3,500 you stated these people could get a whole new gravity drain field put in. If they are faced with a more complex system, say in the $15K to $20K range, we have a little more leverage to make a larger profit.


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## SlickRick (Sep 3, 2009)

Western, I appreciate your input. You seem very knowledgeable on septic for sure.


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## Nayman's Drain (Dec 17, 2010)

I do quite a bit of jetting, but hate doing it in the bitter cold we're having here for obvious reasons.
I also do quite a lot of septic service work.
It seems that around my area, most of the septics work on pump-out systems, which in and of itself presents a whole different set of problems to overcome.

Reading your first post, Western, you say you encountered fairly heavy sludge in the line. Would that biomass be equal to say, a kitchen line with that black, gunked soap & grease? Or more like kitchen grease in a 4 inch line in a restaurant w/o a grease-trap.
The reason I ask, is that while I have never encountered the opportunity to jet a leach field, I have done 4" drains in shops servicing the oil patch here. Fairly heavy oily deposits/sludge, much like what you describe, and 100% success.
Using my 3/8 spinner nozzle, I worked against flow for 98% of a 275 foot DWV coming from the mechanical shop thru the offices, under the parking lot and out to the manhole. (the other 6 feet or so, I had to work with flow on account of sharp, short 90s. The trick is to have water flowing, carrying the sludge as you loosen it from the pipes. I used a handy 2" firehose from the washbay, opened about 1/2 way.
Slow going, using lots of water to carry the sludge away will probably get that line clean as a whistle.
My jetter is a modified, beefed up pressure-washer that will put out [email protected] when run at max by a 13HP Honda engine. Lowest psi is around 1800(gpm not known). If I need something lower than that, I use my electric jetter (1500psi max @ 4GPM).
At the 4400psi, the jetter will drag the hose about 200 feet, and if I assist by pushing it down the line, I can get another 75 feet.
MY concern would be to find out what the perforated lines in the field are made of. IF it's the black, thin, perforated plastic that they use for weeping tile as well, a really low PSI is called for. High PSI will tear that stuff to shreds in no time flat.
Western, I'm going to send you a PM with my numbers if you have any Qs, just call.


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